U.S. Naval Research Laboratory Chemistry Division

MTADS Program

User’s Guide

TEMTADS MP 2x2 Cart

v2.00

May 19, 2014

Revision History:

0.90 09/07/2012 Initial Release, DRAFT designation, Based on software builds TEM_Datalogger v3.3.1, TEM_Tablet v3.3.0

0.91 09/10/2012 Updated file format information in Appendix C, Section C.1 0.92 09/12/2012 Added photo and text regarding interior view of cart 0.93 11/17/2012 Populated Section 10, Geosoft Oasis montaj v7.5 UN

Build (T1 08/22/2012) 0.94 01/04/2013 Updated for software builds TEM_Datalogger v4.0.5, TEM_Tablet v4.0.5 1.00 06/05/2013 Removed DRAFT designation

Updated for software builds TEM_Datalogger v5.1.0, TEM_Tablet v5.1.0, Geosoft Oasis montaj v8.0.1 20130403.35509, ConvertTEMTADS v2.2.0 2.00 05/19/2014 Added dynamic data collection section and discussion of the sensor

function test functionality. Updated for software builds TEM_Datalogger v5.6.0, TEM_Tablet v5.6.0, Geosoft Oasis montaj Testing Beta v8.2 20140306.49824, SensorFunctionReference v1.1.0, ConvertTEMTADS v2.2.0, EM3D 2013 v7.14.01.18

Contents

Figures............................................................................................................................................ iii

Tables .............................................................................................................................................. x

Acronyms ....................................................................................................................................... xi

1.0 Introduction ......................................................................................................................... 1

1.1 Organization of this document ........................................................................................ 1

2.0 Technology ......................................................................................................................... 1

2.1 Technology Description .................................................................................................. 1

2.1.1 TEMTADS/3D EMI Sensors ...................................................................................... 1

2.1.2 Application of the Technology ................................................................................... 2

2.1.3 Development of the Technology ................................................................................. 2

2.2 Advantages and Limitations of the Technology ............................................................. 3

3.0 System Overview ................................................................................................................ 4

3.1 TEMTADS MP 2x2 Cart ................................................................................................ 4

3.1.1 Data Acquisition User Interface.................................................................................. 5

4.0 System Setup ....................................................................................................................... 6

4.1 Uncrating and Assembling The System .......................................................................... 6

4.2 IMU Installation ............................................................................................................ 10

4.3 GPS Installation ............................................................................................................ 11

4.4 Electronics Backpack .................................................................................................... 13

4.5 Interconnections ............................................................................................................ 14

4.6 Support Equipment / Battery Chargers ......................................................................... 17

4.7 Sled Mode ..................................................................................................................... 17

4.8 Litter Mode ................................................................................................................... 21

i

5.0 System Start Up ................................................................................................................ 22

5.1 Connecting Batteries ..................................................................................................... 22

5.2 System Startup .............................................................................................................. 22

5.2.1 System Configuration ............................................................................................... 23

6.0 IMU Installation Orienation Testing ................................................................................. 36

7.0 Sensor Function Testing ................................................................................................... 38

8.0 Dynamic Data Collection .................................................................................................. 42

9.0 Cued Data Collection ........................................................................................................ 48

10.0 Data Handling ................................................................................................................... 61

10.1 Data Transfer ................................................................................................................ 61

10.2 Data Conversion............................................................................................................ 61

11.0 System Shutdown.............................................................................................................. 63

11.1 System Shutdown.......................................................................................................... 63

11.2 Tablet Shutdown ........................................................................................................... 63

11.3 Disconnecting Batteries ................................................................................................ 63

12.0 System Diagnostics ........................................................................................................... 65

12.1 Location and Orientation Indicators ............................................................................. 65

12.2 TEM Data Diagnostics .................................................................................................. 69

13.0 System Maintenance ......................................................................................................... 73

14.0 Generating A Sensor Function Reference File ................................................................. 75

15.0 Data Processing ................................................................................................................. 79

16.0 References ......................................................................................................................... 89

Appendix A. Communications Configuration Details ......................................................... A-1

A.1 Physical Connection.................................................................................................... A-1

ii

A.2 Wired Ethernet Connection......................................................................................... A-1

A.3 Wireless Ethernet Connection..................................................................................... A-1

A.4 Legacy Wireless Ethernet Connection ........................................................................ A-2

Appendix B. Cable Wiring Schematics ................................................................................ B-1

Appendix C. Data Formats ................................................................................................... C-1

C.1 TEM Data file (*.TEM) .............................................................................................. C-1

C.2 Location and Orientation DatA file (*.gps) ................................................................ C-2

C.3 Field Notes file (*.txt) ................................................................................................. C-3

Appendix D. Software Configuration Details ...................................................................... D-1

D.1 TEM_DataLogger Windows Registry Settings .......................................................... D-1

D.2 TEM Datalogger Notes Configuration File ................................................................ D-2

D.3 TEM Datalogger Sensor Reference File ..................................................................... D-2

D.4 EM3D 2013 Configuration File .................................................................................. D-2

Figures

Figure 2-1 – Individual TEMTADS/3D EMI sensor with 3-axis receiver under construction. ................................................................................................................1

Figure 3-1 – TEMTADS/3D EMI sensor array with weather cover removed (left). Sketch of the EMI sensor array showing the position of the four sensors. The tri-axial, revised EMI sensors are shown schematically (right). The direction of travel for the array and the orientation of the sensor cubes are indicated. ..................4

Figure 3-2 – The NRL TEMTADS Man-Portable 2x2 Cart (left) and TEMTADS MP 2x2 Cart with GPS Antenna Tripod (right)........................................................................4

Figure 3-3 – (left) TEMTADS 2x2 Electronics Backpack, (right) Screenshot of Cued Mode Interface ............................................................................................................5

Figure 3-4 – EM3D User Interface – Dynamic Mode .....................................................................6

iii

Figure 4-1 – (left) MP System packed in wooden crate, rotated to show door (right) crate with door removed ......................................................................................................7

Figure 4-2 – Inside wheel spacer configuration for Wheeleez tire ..................................................7

Figure 4-3 – Inside wheel spacer configuration for Wheeleez tire with wheel in place ..................8

Figure 4-4 – Outside wheel spacer configuration for Wheeleez tire, progression as washer and cable tie are installed. ...........................................................................................8

Figure 4-5 – MP System handle bracket, (left) as shipped, (center and right) assembled with handle. .................................................................................................................9

Figure 4-6 – Sensor Cart As Shipped with Sensors and GPS Tripod Installed. Bulkhead Connectors Are Terminate Installed Internal Cable Umbilical (Not Shown). ............9

Figure 4-7 – (left) IMU with data / power cable disconnected, (right) data / power cable connected. .................................................................................................................10

Figure 4-8 –IMU data / power cable and (left) serial extension cable, (right) power cable. .........10

Figure 4-9 – (left) IMU shown on mounting plate, cable removed for clarity, (right) IMU mount bolts with one wingnut installed (view from underneath). ............................11

Figure 4-10 – IMU with Data / Power cable attached, indicating proper cable run. .....................11

Figure 4-11 – (left) GPS antenna installed on MP Cart, (right) Combined GPS / IMU cable run from GPS tripod to cart handle. ................................................................12

Figure 4-12 – Banded DB-9 Serial Extension Cable .....................................................................12

Figure 4-13 – Sensor Cable Bundle Secured to Cart Handle.........................................................13

Figure 4-14 – Electronics Housing and Battery Box Strapped into Backpack ..............................14

Figure 4-15 – DataLogger2 Tx Interconnect Panel .......................................................................15

Figure 4-16 – DataLogger2 Tx Interconnect Panel with Cables in Place ......................................15

Figure 4-17 – DataLogger2 Rx Interconnect Panel .......................................................................16

Figure 4-18 – DataLogger2 Rx Interconnect Panel with Cables in Place .....................................16

Figure 4-19 –Sled Mode (left) Tool Bag of Provided Sled Parts, (right) Unpacked Tool bag and Skis. .............................................................................................................18

iv

Figure 4-20 –Sled Frame ...............................................................................................................18

Figure 4-21 – (left) threaded rod and plug inserted into ski, (right) standoff in place. .................19

Figure 4-22 – (left) half-round retaining block, (right) standoff and frame secured together. ....................................................................................................................19

Figure 4-23 – (left) Gusset Support Block Installed, (right) Shorter Optional Standoffs. .............20

Figure 4-24 – Assembled Sled. The frame is version 2 (forthcoming) with additional standoffs, and handle shown is a previous version. ..................................................20

Figure 4-25 – Litter Mode Options (left) sled-based version, (right) cart-based version. .............21

Figure 5-1 – Electronics package, backpack, and batteries, with batteries in place and connected ..................................................................................................................22

Figure 5-2 – RDP Session Initial Screen on the Tablet PC ...........................................................23

Figure 5-3 – Desktop of DL2 with the TEM DataLogger Icon Highlighted .................................24

Figure 5-4 – TEM DataLogger Main Screen .................................................................................25

Figure 5-5 – TEM DataLogger Setup Tab .....................................................................................25

Figure 5-6 – TEM DataLogger Location and Orientation Tab ......................................................26

Figure 5-7 – Observing Location Serial Data Flow .......................................................................26

Figure 5-8 – Observing Orientation Serial Data Flow ...................................................................27

Figure 5-9 – Desktop of DL2 with the EM3D Icon Highlighted ...................................................28

Figure 5-10 – EM3D splash screen ................................................................................................28

Figure 5-11 – EM3D Main GUI screens ........................................................................................29

Figure 5-12 – EM3D Main Control Window .................................................................................29

Figure 5-13 – (left) EM3D Main control window expanded to show settings, and (right) Acquisition parameters window ...............................................................................30

Figure 5-14 – EM3D (left) GPS configuration, (right) GPS configuration with serial flow enabled ......................................................................................................................32

Figure 5-15 – EM3D IMU configuration with serial flow enabled ...............................................33

v

Figure 5-16 – EM3D DAQ .INI File View Window .....................................................................35

Figure 6-1 – Positive ROLL, PITCH, and YAW rotations of the IMU ........................................36

Figure 6-2 – System displays a Positive ROLL angle for the IMU ...............................................37

Figure 6-3 – System displays a Positive PITCH angle for the IMU ..............................................37

Figure 7-1 – Standard acquisition parameters for cued surveys ....................................................38

Figure 7-2 – Standard acquisition parameters for dynamic surveys ..............................................39

Figure 7-3 – TEM Tablet Sensor Function tab, ready to collect a background .............................40

Figure 7-4 – TEM Tablet Sensor Function tab, ready to conduct a Sensor Function Test ............41

Figure 7-5 – Test item positioned for a sensor function test (left panel) and examples of the test results (right panels) .....................................................................................41

Figure 8-1 – DL2 Desktop with the EM3D application icon highlighted ......................................42

Figure 8-2 – EM3D Main Screens at Startup .................................................................................43

Figure 8-3 – System and Operators Collecting Dynamic Data ......................................................43

Figure 8-4 – EM3D Main GUI with Setup Shown ........................................................................44

Figure 8-5 – EM3D Data Table with Three Modes Shown ...........................................................45

Figure 8-6 – EM3D “Dancing” Arrows with a significant signal present over sensor #3 .............45

Figure 8-7 – EM3D Main Screens Ready to Collect Data .............................................................46

Figure 8-8 – EM3D Main Screen Ready to Collect Data ..............................................................46

Figure 8-9 – EM3D Main Screen While Collecting Data ..............................................................47

Figure 9-1 –Tablet PC Desktop .....................................................................................................48

Figure 9-2 – TEM Tablet Main Screen at Startup ..........................................................................49

Figure 9-3 – Filename Textbox Location on TEM Tablet Main Screen ........................................49

Figure 9-4 – Filename Entry Keyboard with Filename “010” Entered. ........................................50

Figure 9-5 – TEM Tablet Main Screen with Filename Entered .....................................................50

vi

Figure 9-6 – TEM Tablet Main Screen with Data Collection Button Locations Highlighted ...............................................................................................................51

Figure 9-7 – TEM Tablet Main Screen at Beginning of Data Collection Cycle ............................52

Figure 9-8 – TEM Tablet Main Screen with Typical Background Data Presented .......................53

Figure 9-9 – TEM Datalogger Main Screen with Typical Background Data Presented ...............54

Figure 9-10 – TEM Tablet Main Screen with Standard 4-inch Al Sphere Data Presented ...........56

Figure 9-11 – TEM Tablet Location Screen with Data Presented for a Standard 4-inch Al Sphere .......................................................................................................................56

Figure 9-12 – TEM Tablet Polarization Screen with Data Presented for a Standard 4-inch Al Sphere ..................................................................................................................57

Figure 9-13 – TEM Tablet Main Screen with Data Presented for a Small ISO80 .........................57

Figure 9-14 – TEM Tablet Inversion Location Screen with Data Presented for a Small ISO80 ........................................................................................................................58

Figure 9-15 – TEM Tablet Inversion Polarization Screen with Data Presented for a Small ISO80 ........................................................................................................................58

Figure 9-16 – TEM Tablet Main Screen with the Note Button Highlighted .................................59

Figure 9-17 – TEM Tablet Field Notes Dialog ..............................................................................59

Figure 9-18 – TEM Tablet Field Notes On-Screen Keyboard .......................................................60

Figure 9-19 – TEM Tablet Field Notes Dialog Filled Out .............................................................60

Figure 10-1 – DataLogger2 Rx Interconnect Panel with USB Key Inserted for Data Transfer .....................................................................................................................61

Figure 10-2 – ConvertTEMTADS Main Screen .............................................................................62

Figure 10-3 – ConvertTEMTADS Select File Dialog ....................................................................62

Figure 10-4 – ConvertTEMTADS Main Screen After Conversion is Complete ............................63

Figure 11-1 – Desktop of the DataLogger2 Computer with the Shutdown Batch File Highlighted ...............................................................................................................64

Figure 12-1 – TEM Datalogger Main Screen at Idle .....................................................................66

vii

Figure 12-2 – TEM Datalogger Main Screen with the GPS Receiver Unplugged ........................67

Figure 12-3 – TEM Datalogger Main Screen with RTK Degraded ..............................................67

Figure 12-4 – TEM Datalogger Main Screen with the IMU power unplugged ............................68

Figure 12-5 – TEM Datalogger Main Screen During Data Collection with the IMU power unplugged ..................................................................................................................68

Figure 12-6 – TEM Datalogger Main Screen with Typical Background Data Presented .............69

Figure 12-7 – TEM Datalogger Error Message for Low Transmitter Current ..............................70

Figure 12-8 – TEM Datalogger Main Screen with Background Data Collected as Data ..............71

Figure 12-9 – TEM Datalogger Main Screen with a 4-inch Aluminum Sphere Centered above the Array .........................................................................................................71

Figure 13-1 – Internal View of the Electronics Housing ...............................................................74

Figure 13-2 – Air Inlet Fan Cover Location Shown With Respect to Tx Connector Panel and Main On/Off Switch ...........................................................................................74

Figure 14-1 – TEMTADS Sensor Function Reference Generator Main Screen ...........................76

Figure 14-2 – TEMTADS Sensor Function Reference Generator File Selection Dialog..............76

Figure 14-3 – TEMTADS Sensor Function Reference Generator Main Screen with Data .TEM File Selected ...................................................................................................77

Figure 14-4 – TEMTADS Sensor Function Reference Generator Background Selection Dialog ........................................................................................................................78

Figure 14-5 – TEMTADS Sensor Function Reference Generator Main Screen with Both .TEM Files Selected ..................................................................................................78

Figure 15-1 – Oasis montaj Load Menu Dialogs for (left) UX Analyze Advance and (right) IGRF ..............................................................................................................79

Figure 15-2 – (left) UX Analyze Settings Dialog, (right) Compute Single Point GRF Values Dialog ............................................................................................................80

Figure 15-3 – Import Advanced Sensors Dialog ...........................................................................80

Figure 15-4 – (left) Display Decay – QC Input, and (right) Calculate Background Statistics Dialog ........................................................................................................82

viii

Figure 15-5 – Display Decay – QC results plot for the Overlay-All option ..................................83

Figure 15-6 – Level Advanced Sensor Data Dialog (left), Decay Display – QC Dialog (right) ........................................................................................................................84

Figure 15-7 –Decay Display – QC Results for Leveled Data ........................................................86

Figure 15-8 – Modeling Parameters – Static Survey Mode – Panels 1 and 2 ...............................87

Figure 15-9 – Modeling Parameters – Static Survey Mode – Panels 3 and 4 ...............................87

Figure 15-10 – Modeling Results – Shotput, Static Survey Mode ................................................88

Figure A-1 – DataLogger2 Wireless Network Configuration Screens #1 .................................. A-3

Figure A-2 – DataLogger2 Wireless Network Configuration Screens #2 .................................. A-3

Figure A-3 – DataLogger2 Wireless Network Configuration Screens #3 .................................. A-4

Figure B-1 – Datalogger 2 Rx Connector Schematic ..................................................................B-1

Figure B-2 – Datalogger 2 Tx Connector Schematic ...................................................................B-2

ix

Tables

Table 7-1 – Standard data acquisition parameters .........................................................................39

Table A-1 – DataLogger2 Wired Ethernet Address ................................................................... A-1

Table A-2 – Connectify DataLogger2 Wireless Ethernet Address ............................................. A-2

Table A-3 – DataLogger2 Wireless Ethernet Address ............................................................... A-2

Table B-1 – Datalogger 2 Rx Connector Pin Out ........................................................................B-1

Table B-2 – Datalogger 2 Tx Connector Pin Out ........................................................................B-2

Table B-3 – Tx1 Tyco 206037-1 and Tx2 206036-1 Pin Out ......................................................B-3

Table B-4 – Tx2 Molex 19-09-1029 Receptacle Pin Out (socket contacts): ...............................B-3

Table B-5 – Rx1 Tyco 206305-1 and Rx2 206306-1 Pin Out .....................................................B-3

Table B-6 – Rx2 Switchcraft / Conxall 3280-9sg-524 and Sensor Switchcraft / Conxall 4282-9PG-300 Pin Out ...........................................................................................B-3

x

Acronyms

Abbreviation DefinitionAHRS Attitude Heading Reference SystemAOL Advanced Ordnance LocatorAPG Aberdeen Proving GroundASCII American Standard Code for Information InterchangeCOM# The label assigned by a PC to a given serial (RS-232) portDOP Dilution of PrecisionEMI Electro-Magnetic InductionESTCP Environmental Security Technology Certification ProgramGPS Global Positioning SystemHDOP Horizontal Dilution of Precision (2D)IEEE Institute of Electrical and Electronics EngineersMP Man-PortableMR Munitions ResponseMTADS Multi-sensor Towed Array Detection SystemNRL Naval Research LaboratoryPDOP Position Dilution of Precision (3D)QC Quality ControlRDP (Microsoft) Remote Desktop ProtocolRMS Root-Mean-SquaredRx ReceiverSAIC Science Applications International CorporationSWaP Size, Weight, and PowerTEM Time-domain Electro-MagneticTEMTADS Time-domain Electro-Magnetic MTADSTOI Target of InterestTx Transmit(ter)UXO Unexploded OrdnanceUSB Universal Serial BusVGA Video Graphics Array

xi

xii

1.0 INTRODUCTION

1.1 ORGANIZATION OF THIS DOCUMENT

This document is designed to serve as a User’s Guide for the NRL TEMTADS MP 2x2 Cart system, or MP System. A brief description and history of the system’s development will be presented. Then, the reader will be walked through setting up, starting, running, extracting data from, and shutting down the system. The Appendices provide reference material that may be useful to the user.

2.0 TECHNOLOGY

2.1 TECHNOLOGY DESCRIPTION

2.1.1 TEMTADS/3D EMI Sensors

The original design of the MP System utilized the standard TEMTADS Electromagnetic Induction (EMI) sensor. Based on the results of the MP system demonstration at the Aberdeen Proving Ground (APG) Standardized UXO Test Site in August, 2010 [1,2], revision of the sensor technology was indicated. A modified version of the sensor element was designed and built, replacing the single, vertical-axis receiver coil of the original sensor with a three-axis receiver cube. These receiver cubes are similar in design to those used in the second-generation Advanced Ordnance Locator (AOL) and the Geometrics MetalMapper (ESTCP MR-200603) system with dimensions of 8 cm rather than 10 cm. The CRREL MPV2 system (ESTCP MR-201005) uses an array of five identical receiver cubes and a circular transmitter coil. The new sensor elements are designed to have the same form factor as the original, aiding in system integration. A TEMTADS/3D coil under construction is shown in Figure 2-1.

Figure 2-1 – Individual TEMTADS/3D EMI sensor with 3-axis receiver under construction.

1

Decay data are collected with a 500 kHz sample rate after turn off of the excitation pulse for up to 25ms. This data collection configuration can result in raw decays of up to 12,500 points; too many to be used practically. These raw decay measurements are typically grouped into logarithmically-spaced “gates” with center times ranging from 25 µs to 24.35 ms with proportional widths and are saved to disk.

2.1.2 Application of the Technology

This technology may be applied in either of two data collection mode, dynamic or survey mode and cued mode. In dynamic mode, a series of lane markers (e.g. strings and stakes) are placed over the survey area to provide a visual guide for maintaining lane spacing. Data are then collected to cover the area by pushing the MP System along the indicted lanes at a slow walking speed (0.75 m/s). The status of the transient EMI (TEM) sensors is indicated on the operator screen. The operator is able to review positioning and orientation data for the platform during data collection. In cued mode, a list of target positions is developed from some source. As an example, the anomaly list could be derived from EM61-MK2 data previously collected over the site. The cart is then positioned over each target, the transmitter for each array sensor fired in sequence, and decay data are collected from all twelve receive coils for each excitation. These data are stored electronically on the data acquisition computer. Prior to moving to the next target, the operator evaluates a display of the 4 monostatic, 3-axis signal amplitude decays, evaluates the symmetry of the responses, and compares the values at the first usable time gate (89 µs) to a ‘low SNR’ threshold. If desired, the collected data can be processed by a single-dipole inversion routine to extract target location and shape parameters. Of primary interest is the offset between the array location and the fit location. If the fit location is outside of the specified tolerance (e.g. 30 cm), the operator can elect to reposition the array and collect additional data for the target prior to leaving the target location.

2.1.3 Development of the Technology

The MP System is a man-portable four-element TEM system designed and built by NRL with funding from ESTCP to transition the TEM sensor technology of the TEMTADS towed array (ESTCP Project MR-200601) to a more compact, man-portable configuration for use in more limiting terrain under project MR-200909. This system was initially configured to operate in a cued mode, where the target location is already known. Preliminary testing of the initial system configuration [3] found that for high SNR (≥ 30) targets one measurement cycle provided enough information to support classification. For deeper and/or weaker targets, more robust estimates of target parameters were obtained by combining two closely-spaced measurements. Two measurements per anomaly were typically made proactively to avoid the potential need to revisit a target a second time. As part of project MR-200909, a demonstration was conducted to rigorously investigate the capabilities of this new sensor platform for unexploded ordnance (UXO) classification in a cued data collection mode at the APG Standardized UXO Test Site in August, 2010 [4]. Those results indicated that the inversion performance of the system was not comparable to that of the full TEMTADS array for lower SNR targets due to the limits of the smaller data set (fewer looks at the target). Revision of the sensor technology was indicated for

2

the MP System to collect sufficient data over an anomaly. A modified version of the EMI sensor was designed and built, replacing the single, vertical-axis receiver loop of the original coil with a tri-axial receiver cube. These receiver cubes are identical in design to those used in the CRREL MPV2 system (ESTCP MR-201005). The new sensor elements were designed to have the same form factor as the originals, aiding in system fabrication. The completed MP system was demonstrated by the NRL team as part of the ESTCP Munitions Response Live Site Demonstrations at several sites including the former Camp Beale, CA in June, 2011 [5], at the former Spencer Artillery Range, TN in May, 2012 [6], and at the Massachusetts Military Reservation, MA in June, 2012 [7]. Three additional MP Systems have been fabricated for loan to other groups as part of the ESTCP Munitions Response Live Site Demonstrations. The second unit was first used at the former Camp Beale, CA in September – October, 2012 and has been in service since. The third and fourth loaner units have since joined the loaner pool.

As part of several of these recent demonstrations, the MP System has been deployed in a dynamic mode prior to data collection in cued mode. The results have been encouraging [6] with lessons learned. Development and further demonstrations of this mode of operation are ongoing.

2.2 ADVANTAGES AND LIMITATIONS OF THE TECHNOLOGY

The TEMTADS 5x5 Array was designed to combine the data advantages of a gridded survey with the coverage efficiencies of a vehicular system. The resultant data should therefore be equal, if not better, in quality to the best gridded surveys (the relative position and orientation of the sensors will be better than gridded data) while prosecuting many more targets each field day.

There are obvious limitations to the use of this technology. The TEMTADS 5x5 Array is 2-m square in area and mounted on a trailer. Fields where the vegetation or topography interferes with passage of a trailer of that size will not be amenable to the use of the present array.

The MP System was designed to offer similar production rates in difficult terrain and treed areas that the TEMTADS 5x5 Array cannot access. With the upgraded TEMTADS/3D sensors, similar performance can be achieved with similar classification-grade data quality. The MP array is 80 cm on a side and mounted on a man-portable cart. Terrain where the vegetation or topography interferes with passage of a cart of that size will not be amenable to the use of the system.

The other serious limitation is anomaly density. For all systems, there is a limiting anomaly density above which the response of individual targets cannot be separated individually. We have chosen relatively small sensors for this array which should help with this problem but we cannot eliminate it completely. Recent developments, including solvers designed for classification in multiple-object scenarios such as Leidos’s multi-target solver [8], are being evaluated and their performance characteristics in cluttered environments determined.

3

3.0 SYSTEM OVERVIEW

3.1 TEMTADS MP 2X2 CART

The MP System is a man-portable system comprised of four of the TEMTADS/3D EMI sensors discussed in Section 2.1.1 arranged in a 2x2 array as shown in Figure 3-1. Direction of travel is to the left Figure 3-1 (left) and up in Figure 3-1 (right). The orientation of the sensor cubes is also noted. The MP System, shown in Figure 3-2 (left) at Fort Rucker, AL, is fabricated from PVC plastic and fiberglass. The center-to-center distance is 40 cm yielding an 80 cm x 80 cm array. The array is typically deployed on a set of wheels resulting in a sensor-to-ground offset of approximately 20 cm. The transmitter electronics and the data acquisition computer are mounted in the operator backpack, as shown in Figure 3-3. The MP System can be operated in two modes; dynamic or survey mode and cued mode. A Global Positioning System (GPS) antenna and (optionally) an inertial measurement unit (IMU) are mounted above the TEM array as shown in Figure 3-2 (right). Data collection is controlled in dynamic mode using G&G Science’s EM3D application suite, the same software that is used for the Geometrics MetalMapper systems. In cued mode, the locations of the anomalies must already be known and flagged for reacquisition. Custom software written by NRL provides cued data acquisition functionality.

Figure 3-1 – TEMTADS/3D EMI sensor array with weather cover removed (left). Sketch of the EMI sensor array showing the position of the four sensors. The tri-axial, revised EMI sensors are shown schematically (right). The direction of travel for the array and the orientation of the sensor cubes are indicated.

Figure 3-2 – The NRL TEMTADS Man-Portable 2x2 Cart (left) and TEMTADS MP 2x2 Cart with GPS Antenna Tripod (right)

1 2

4 3EM Sensor

Direction of Travel

+Y

+X+Z

Sensor Orientation

4

Figure 3-3 – (left) TEMTADS 2x2 Electronics Backpack, (right) Screenshot of Cued Mode Interface

In dynamic mode, a series of lane markers (e.g. strings and stakes) are placed over the survey area to provide a visual guide for maintaining lane spacing, as shown in Figure 3-2 (left). Data are then collected to cover the area by pushing the MP System along the indicted lanes at a slow walking speed (0.75 m/s). The status of the TEM sensors is indicated on the operator screen. The operator is able to review positioning and orientation data for the platform during data collection.

In cued mode, the operators position the cart over each anomaly location in turn and collect a set of TEM data. Geolocation and cart orientation are monitored and recorded. Functionality to record field notes is provided. If anomaly flagging is unavailable or undesirable, it is possible to load a list of virtual flag locations into the vendor-provided survey controller for the GPS unit and use the provided interface for anomaly-to-anomaly navigation. This has been tested using a Trimble R8 GNSS version 3 GPS receiver and a TSC2 survey controller.

3.1.1 Data Acquisition User Interface

The data acquisition computer is mounted on a backpack worn by one of data acquisition operators, shown in Figure 3-3 (left). The second operator controls the data collection using a tablet computer which wirelessly (IEEE 802.11n) communicates with the data acquisition computer. The second operator also manages field notes and team orienteering functions. In Figure 3-2 (left), a data collection team is shown in action. In dynamic mode, the EM3D software is operated directly via Microsoft Remote Desktop (RDP) Connection. The EM3D user interface is shown in Figure 3-4. In cued mode, a separate application runs on the tablet computer and the RDP is limited to system startup/shutdown and configuration. The tablet PC user interface for cued mode is shown in Figure 3-3 (right).

5

Figure 3-4 – EM3D User Interface – Dynamic Mode

4.0 SYSTEM SETUP

The MP System is typically shipped in a 48” x 55” x 66” palletized, wooden crate weighing approximately 400 pounds. A #2 Phillips-head screwdriver is required to uncrate the system. A cordless drill, a charged battery, and at least one #2 Phillips-head bit are recommended. Additional equipment is shipped in Pelican™-style plastic shipping cases. These cases may arrive separately, shrunk-wrapped to the top of the crate or to a pallet, or in a second wooden crate.

The following directions for unpacking and assembling the MP System are lightly adapted from the TEMTADS User Manual Addendum [9], which is provided in printed form with each MP System. This document is intended to help you through the unpacking, setup, and repacking of the MP System.

4.1 UNCRATING AND ASSEMBLING THE SYSTEM

The system is delivered in a wooden crate, as shown in Figure 4-1. The first step is to locate the side panel on the box marked “DOOR,” shown in Figure 4-1 (left), and remove the panel using a screwdriver or cordless drill and bit. Remove the contents carefully, taking note of how they were packed to assist in repacking the system at the end of the survey. Figure 4-1 (right) shows how the crate contents should look upon receipt and how it should look when returned. If any significant shifting has occurred during shipment, please contact NRL to discuss.

6

Figure 4-1 – (left) MP System packed in wooden crate, rotated to show door (right) crate with door removed

Set the cart on the provided foam block when removed from the crate. Put the wheels on the cart. Care should be taken to keep the axles and the inside of the wheel hubs free and clear of debris. The wheels are Wheeleez 15-inch Tuff-Tire Wheels.1 For lighter-duty usage, standard garden cart wheels,2 typically available at Lowe’s, may be substituted. The Delrin axle adapters are press-fit into the wheel and are required for the wheel to be installed on the axle. Which type of wheels are provided with the system will determine the number and placement of spacers on the axles. The configuration of spacers for the Wheeleez wheels is shown in Figure 4-2, Figure 4-3, and Figure 4-4.

Figure 4-2 – Inside wheel spacer configuration for Wheeleez tire

1 Wheeleez 38 cm (15") Polyurethane Foam Tuff-Tire Wheel, P/N: WZ1-38TT-PB 2 PreciseFit 14” Plastic Wheel, Model 0188327

7

Figure 4-3 – Inside wheel spacer configuration for Wheeleez tire with wheel in place

Figure 4-4 – Outside wheel spacer configuration for Wheeleez tire, progression as washer and cable tie are installed.

Note: The spacers were placed on the axles prior to shipment and are held on by an open zip tie.

Once spacers and wheels are in place, secure the wheels with zip ties. The handle needs to be reattached to the cart next. The cart handle bracket, as shipped is shown in Figure 4-5. Four three-inch-long fiberglass bolts (1/2” diameter)3 and the accompanying washers4 and nuts5 are used to attach the handle to the cart, two on each side. These bolts can wear out over time. A small supply of the fiberglass hardware required for the system are provided with the system. Figure 4-5 (right) and (center) shows the proper alignment of the handle and gussets on one side

3 McMaster-Carr P/N: 91345A724, 1/2”-13 x 3” Fiberglass Cap Screw Flange Head 4 McMaster-Carr P/N: 91395A033, 1/2”-13 Fiberglass Hex Nut 5 McMaster-Carr P/N: 90940A019, 1/2” Durable Polycarbonate Flat Washer

8

with the bolts, washers, and nuts in place. As with all the plastic and fiberglass hardware, DO NOT OVER TIGHTEN!!

Note: All necessary bolts, washers and nuts for the handle are already in place and should be so for repacking.

Figure 4-5 – MP System handle bracket, (left) as shipped, (center and right) assembled with handle.

The sensor cart is provided with the TEMTADS/3D sensors installed and cabled to a bulkhead. The cart ships with the GPS tripod installed as well. As shown in Figure 4-6, the sensors and cable umbilical are not shown.

Figure 4-6 – Sensor Cart As Shipped with Sensors and GPS Tripod Installed. Bulkhead Connectors Are Terminate Installed Internal Cable Umbilical (Not Shown).

9

4.2 IMU INSTALLATION

An inertial measurement unit (IMU) is provided with the system. This device is fairly delicate and not waterproof, so it is shipped separately and with the cabling disconnected. To install, first secure the data / power cable to IMU using a small slotted screw driver. Tighten both screws until snug. It is important to alternate the tightening of both screws to keep the connector straight during the process. Otherwise it may be damaged. See Figure 4-7.

Figure 4-7 – (left) IMU with data / power cable disconnected, (right) data / power cable connected.

Next, connect the DB-9 connection on the data / power cable to a 9-pin serial extension cable (male / female). See Figure 4-8 (left). Then connect the IMU power connector (barrel connector) to the matching end of the IMU power cable. See Figure 4-8 (right).

Figure 4-8 –IMU data / power cable and (left) serial extension cable, (right) power cable.

Attach the IMU to the IMU Mounting Plate located under the GPS Mounting Plate on the cart, using two nylon screws and wing nuts. DO NOT CROSS THREAD OR OVER TIGHTEN. See Figure 4-9. The location of the IMU below the GPS antenna provides some measure of protection from the weather. The IMU housing is not weather sealed and care must be taken to protect the IMU from water infiltration.

10

Figure 4-9 – (left) IMU shown on mounting plate, cable removed for clarity, (right) IMU mount bolts with one wingnut installed (view from underneath).

Install the IMU cable assembly and run the cable towards the rear of cart. Secure the cable assembly as shown in Figure 4-10. DO NOT PULL CABLE TIGHT ON THE FIRST TURN. Place a zip tie on the starboard upright post all thread to provide strain relief for the cable.

Figure 4-10 – IMU with Data / Power cable attached, indicating proper cable run.

4.3 GPS INSTALLATION

A GPS receiver and antenna are NOT provided with the MP System. Most testing has been with the Trimble R8 v3 GNSS Smart Antenna, but any receiver with an RS-232 output that can output the $GPGGA or $PTNL, GGK location strings should work. This receiver has several features which lend itself to use, including an exchangeable battery, a DB-9 serial output connector, integrated receiver and antenna, and good Size, Weight, and Power (SWaP) characteristics.

First, mount the GPS antenna to the GPS Mounting Plate on the cart as shown in Figure 4-11 (left). The mount is a standard 5/8”-11 thread. The length of exposed thread can be adjusted by loosening the nuts on the under of the mounting upright and tightening the nuts on the upper surface.

11

Figure 4-11 – (left) GPS antenna installed on MP Cart, (right) Combined GPS / IMU cable run from GPS tripod to cart handle.

Connect a serial cable to the GPS receiver and to a second DB-9 serial extension cable.

Note: In the case of the Trimble R8 v3 GNSS, this cable needs to have a null-modem configuration.

One of the provided serial extension cables should be marked with black ink to help trace which cable is connected to which port, as shown in Figure 4-12. Using small zip ties, gather both the GPS and IMU cables together into a single cable bundle, using the heavier GPS cable to strain relief the IMU cable. Start the process at the Mounting Plates and continue all the way to the data acquisition computer. The GPS serial cable connects to COM1. The IMU serial cable connects to COM2 and the IMU power cable connects to the BNC connector labeled “IMU PWR.” See Figure 4-11 (right). Secure the cable bundle to the cart handle. See Figure 4-13.

Figure 4-12 – Banded DB-9 Serial Extension Cable

12

Figure 4-13 – Sensor Cable Bundle Secured to Cart Handle

4.4 ELECTRONICS BACKPACK

The data collection electronics are primarily contained within the electronics housing located in the backpack. The only exceptions for the TEM electronics are the receiver preamplifiers which are integral to the receiver cubes. The electronics backpack is designed to be reasonably rugged and weather resistant. Air intakes are shrouded and waterproof connectors were used when available. It is recommended to cover the backpack with a poncho or similar if caught outside during light rainfall.

NOTE: Operation through standing water or in moderate or greater rainfall is not recommended both for the protection of the equipment and due to induced strong gradients in the background response.

The electronic housing should be removed from its shipping container and attached to the backpack. The electronics housing is attached to the backpack6 using webbed belting material, as shown in Figure 4-14.

The battery box is located at the bottom of the backpack. The system is powered by two Ultralife UBI-2590 Lithium-Ion (Li-Ion) batteries,7 one for the transmitter and one for the computer. Place one battery in each compartment of the battery box. The data collection computer and electronics will run for two hours plus on a single UBI-2590 battery.

6 Currently we use the Granite GEAR Stratus Flatbed, Model # 586000. This item is currently discontinued by the manufacturer. 7 http://ultralifecorporation.com/be-military/products/military-rechargeable/UBBL02/

13

Figure 4-14 – Electronics Housing and Battery Box Strapped into Backpack

The transmitter will run for two – four hours on a single UBI-2590 battery, depending on fractional on-time for the transmitter. Six to eight batteries are required for a typical survey day.

4.5 INTERCONNECTIONS

There are two interconnect panels on the electronics housing. The transmitter interconnect panel is on the bottom of the electronics housing, next to the main power switch, as shown in Figure 4-15. The transmitter cable, Tx1, connector connects to “Tx” connector which is an Amphenol shell size 20 circular military connector. Figure 4-16 shows the Tx interconnect panel with the cables in place. Connect the Amphenol connector on the TX1 cable to the “Tx” connector on the DL2 and to the smaller plastic circular connector on the MP System cart. See Figure 4-11 and Figure 4-13 for how to route the Tx1 cable through the cart handle and to the cart. The transmitter power cable connects to the “PWR” connector which is an Amphenol shell size 12 circular military connector.

14

Figure 4-15 – DataLogger2 Tx Interconnect Panel

The receiver interconnect panel is on the side of the electronics housing, as shown in Figure 4-17. The receiver cable, Rx1, connector connects to “Rx” connector which is an Amphenol shell size 20 circular military connector. Figure 4-18 shows the Rx interconnect panel with the cables in place. See Figure 4-11 and Figure 4-13 for how to route the Rx1 cable through the cart handle and to the cart. The CPU power cable connects to the “CPU Power” connector, which is an Amphenol shell size 12 circular military connector. The CPU power cable is configured to allow for the “hot-swapping” of computer batteries, or the changing of the battery while keeping the computer running. There are several additional connectors on the Rx Interconnect Panel. They include two USB ports connected to the data collection computer. The “USB2” connector is used for the data collection computer’s WiFi adapter. “USB1” is available for data transfer or the connection of a USB keyboard and/or mouse. There is a wired Ethernet jack (ETH), connected to the data collection computer. There is a sticker on the right side of the Rx interconnect panel with the Ethernet IP addresses for the DL2. See Appendix A for further details about the data collection computer’s wired and wireless connectivity.

Figure 4-16 – DataLogger2 Tx Interconnect Panel with Cables in Place

15

The “VGA” connector is provided for connecting an analog computer monitor to the data collection computer. The data collection computer’s two serial (RS-232) ports are available on the “COM1” and “COM2” DB-9 connectors. By default the system is configured to expect GPS data on “COM1” and IMU data on “COM2,” both transmitting at 115,200 baud. The remaining connector, “IMU PWR,” provides +15 VDC power for external devices such as an IMU as a BNC jack connector. The LED on the interconnect panel is the data collection computer’s power LED. When the LED is lit (green), the computer is running.

Figure 4-17 – DataLogger2 Rx Interconnect Panel

Figure 4-18 – DataLogger2 Rx Interconnect Panel with Cables in Place

16

4.6 SUPPORT EQUIPMENT / BATTERY CHARGERS

Two Ultralife CH0004 2-Bay Chargers8 are provide with the MP System to charge the UBI-2590s. If possible, it is recommended to set up a single charger onsite to charge used batteries during the day on an ongoing basis for protection against running out of batteries. Otherwise, additional batteries and chargers can be purchased separately from a variety of vendors9.

NOTE: While it is possible to use and store the UBI-2590 battery at temperature below freezing (32 ºF, 0 ºC), charging Li-Ion batteries at temperatures at or below freezing can shorten battery lifetime and potentially damage the battery [10].

The system is delivered with one of two brands of tablet PCs. The older Archos 9 Tablet PCs10 have removable batteries, each of which will last for at least two hours in the field. There are no OEM or aftermarket chargers for the Archos batteries, so two tablets are provided with the MP System. One is for use in the field. The other is provided as a battery charger and as a backup field tablet. The Archos tablet PCs are only appropriate for cued mode operation. For deployments that may involve dynamic mode data collection, two Motion Computing CL910 tablet PCs11 are provided. These tablets are more powerful than the Archos tablets and are necessary to prevent overloading the data acquisition PC when using RDP. The Motion Computing tablets do not have removable batteries, but their larger internal batteries typically allow for more than a half-day of surveying each. As such, two are provided.

While all connectivity to the data collection computer is planned to occur via WiFi and RDP over wired / wireless networking, it is recommended to have a VGA monitor, keyboard, and mouse available in the field in case of network connectivity issues. VGA monitors typically require an external power source.

4.7 SLED MODE

A sled configuration of the MP System with skis replacing the wheels is available. The sled version is currently only available as a prototype. The finalized version will be available in Summer 2014. If requested, additional parts will be provided. Due to the length of the skis, more assemble is required on-site. A tool bag of parts, one or more pairs of skis, and a different sled frame will be included in the shipment, as shown in Figure 4-19 and Figure 4-20. The provided standoffs place the sensor-to-ground distance at 15 cm. A second set of standoffs is provided that can drop the distance to 10 cm.

8 http://ultralifecorporation.com/be-military/products/chargers/ch0004/ 9 For example, Radio Reconnaissance Technology, Fredericksburg, VA, http://www.radiorecon.com/ 10 http://store.archos.com/pc-tablets.html 11 http://www.motioncomputing.com/us/products/rugged-tablets/cl910

17

Figure 4-19 –Sled Mode (left) Tool Bag of Provided Sled Parts, (right) Unpacked Tool bag and Skis.

Figure 4-20 –Sled Frame

To assemble the sled, the following steps should be followed:

1. Insert threaded rod with plug through holes from the bottom of ski. 2. Slide standoff over threaded rod.

18

Figure 4-21 – (left) threaded rod and plug inserted into ski, (right) standoff in place.

3. Insert half-round retaining block into the four ends of the main sled tubes, if they are not already in place.

4. Place cart frame on the 4 threaded rod post ensuring that the post goes through the half-round retaining blocks.

5. Secure with recessed nut on top of cart frame.

Figure 4-22 – (left) half-round retaining block, (right) standoff and frame secured together.

6. Place gusset support through bottom of ski and secure each with 2 dowels.

19

7. Attach gussets to gusset supports. 8. Insert square fiberglass tube between gusset support and standoff support. 9. Place zip ties around gusset support and standoff support and secure.

Figure 4-23 – (left) Gusset Support Block Installed, (right) Shorter Optional Standoffs.

10. Attach handle to gussets.

Figure 4-24 – Assembled Sled. The frame is version 2 (forthcoming) with additional standoffs, and handle shown is a previous version.

20

Once the sled is assembled the GPS / IMU can be secured to the cart using the same mount from the wheeled cart. If the cart has never been used with a GPS mount, the holes will have to be drilled in the frame. Using the holes in the sensor cover as a template, drill the frame using a ½” drill bit. Also, if you need to adjust the handle height, the holes in the gusset plates will have to be enlarged or you will have to use smaller bolts. Smaller bolts are the preferred method so as not to lessen structural integrity.

4.8 LITTER MODE

A frequent request is for a litter-carried version of the MP System. This currently exists, but only as a prototype. A finalized version is currently under development and should be available in Summer 2014. Two litter-carried versions are currently available on request. They are shown in Figure 4-25. The fiberglass carry poles shown in Figure 4-25 (left) have been replaced with carbon fiber versions, shown in Figure 4-25 (right) which exhibit significantly less flex when the litter is in motion.

Figure 4-25 – Litter Mode Options (left) sled-based version, (right) cart-based version.

21

5.0 SYSTEM START UP

5.1 CONNECTING BATTERIES

To start up the MP System, the first step is to install two UBI-2590 batteries in the backpack and connect each to the electronics housing. One connects to the Tx “PWR” connector using the single-headed TX PWR cable. The second connects to the “CPU PWR” connector using the double-headed CPU PWR cable. The batteries, in place and connected, are shown in Figure 5-1. Make sure to have a charged tablet PC available.

Figure 5-1 – Electronics package, backpack, and batteries, with batteries in place and connected

5.2 SYSTEM STARTUP

The data acquisition computer will be referred to as the DataLogger2 (DL2) for the remainder of the document.

Note: Do NOT have the GPS RS-232 cable connected to the DL2 initially. An issue has been identified wherein, if a GPS receiver is connected to either COM port, the system will attempt to “boot” from the receiver rather than the system hard drive. The severity varies from receiver to receiver and system to system. Both slow booting and total non-booting results have been observed.

Turn DL2’s Main On/Off switch (seen in Figure 4-15) to the “ON” position. The red light will illuminate. Turn on the Tablet PC by pressing and holding the on/off switch for a few seconds. DL2 will beep when the computer starts. When the tablet PC has completed booting, open an RDP session to DL2, as shown in Figure 5-2. For robustness, the computer’s IP address (See Appendix A) is used. If necessary, the username on the DataLogger2 is “Operator” and the password is “temtads”.

22

Figure 5-2 – RDP Session Initial Screen on the Tablet PC

Once the RDP session is open, connect the GPS RS-232 cable, if used, to the DL2.

5.2.1 System Configuration

The TEM DataLogger application is used for cued data collection and offers access to a collection of field QC functionality tools. It is recommended that the operator begin with the TEM DataLogger application, even if the data collection effort will ultimately be a dynamic survey. Start the TEM DataLogger application by selecting and holding the application icon on the desktop, highlighted in yellow in Figure 5-3. When the contextual menu opens, select “Open.” When the application opens, the screen will look like the one shown in Figure 5-4.

The majority of system configuration options are available on the [Setup] tab. Most of the configuration options do not require routine modification, but there are a small number which may. To change them, select the [Setup] tab. The [Setup] tab contents are shown in Figure 5-5. The data collection parameters; block time, number of repeats, and number of stacks are located in the upper middle portion of the screen in the “Acquisition Parameters” frame. The default data collection parameters for MP System cued data collection are: 0.9 seconds, 9 repeats, 18 stacks, decimated decays, 50 µs holdoff time, with 5% gate widths. These parameters result in a 25ms decay time, 122 time gates per decay, and a total data collection time of 1 minute. The default data collection parameters for MP System dynamic data collection are: 0.033 seconds, 3 repeats, 1 stack, decimated decays, 50 µs holdoff time, with 20% gate widths. These parameters result in a 2.78ms decay time, 19 time gates per decay, and a total data collection time of 133 milliseconds. Two buttons are provided to assert the respective setting. The default sensor height in cart configuration is 0.2 m. Data files are by default stored in the “TEM Data” subdirectory of “My Documents.” The data file storage location is set at the bottom of the screen in the “Output Data Files” frame.

NOTE: Standard practice is to not modify the output data file location, but to rather gather the files at the end of each day and place them in a new subdirectory with a useful name such as the day’s date.

23

Figure 5-3 – Desktop of DL2 with the TEM DataLogger Icon Highlighted

In order to provide additional metadata in the data filenames, the two textboxes in the Site Identifiers frame (lower right of tab) can be used to define filename prefixes which will be automatically appended to filenames without requiring additional typing on the operator’s part.

While the two prefixes can be any valid string, the intention is provide the opportunity to provide a “site” or area designation, and a “subsite” designation. For example, if “Site” is defined as “BlossomPoint” and “Sub site” is defined as “testfield” and the operator collects a file with the filename “1315”, the resulting filename will be “BlossomPoint_testfield_1315.tem”.

Data collection parameters related to location and orientation sensors are accessible from the “Location and Orientation” tab, shown in Figure 5-6.

All supported GPS receivers and the supported IMU communicate via RS-232 serial communications. To enable either type of sensor, check the corresponding “Expect …” checkbox. In Figure 5-6, both location and orientation are enabled. Confirm that the correct settings are set (Baud Rate, etc.). The “Serial Data Flow” frame at the bottom of the screen provides an opportunity to verify that each sensor is working correctly. Selecting the “Location” radio button will display the raw NMEA data stream in the textbox, as shown in Figure 5-7.

24

Figure 5-4 – TEM DataLogger Main Screen

Figure 5-5 – TEM DataLogger Setup Tab

25

Figure 5-6 – TEM DataLogger Location and Orientation Tab

Figure 5-7 – Observing Location Serial Data Flow

26

Figure 5-8 – Observing Orientation Serial Data Flow

Additionally, the NMEA output is parsed and the corresponding UTM (meters) Northing and Easting are displayed along with the number of GPS satellites. Functionality with Trimble $GPGGA and $PTNL, GGK NMEA sentences has been tested. At this time, the NMEA sentence checksum is not parsed or verified. Similarly, selecting the “Orientation” radio button will display a representation of the raw binary output string. The output is parsed and Pitch, Roll, and Yaw values are displayed. If the checksum on the string does not verify, a Yaw of “777” is displayed. Bad packets (invalid checksum) are not included in any collected data. Orientation functionality is currently only provided for the Microstrain 3DM-GX3-25 Miniature Attitude Heading Reference System (AHRS).12

If the ultimate goal is to conduct a dynamic survey, the configuration of the EM3D software should be verified as well. Start the EM3D application by selecting and holding the application icon on the desktop, highlighted in yellow in Figure 5-9. When the contextual menu opens, select “Open.” Initially when the application opens, an application “splash screen” will look like the one shown in Figure 5-10.

12 http://www.microstrain.com/inertial/3DM-GX3-25

27

Figure 5-9 – Desktop of DL2 with the EM3D Icon Highlighted

Figure 5-10 – EM3D splash screen

28

Figure 5-11 – EM3D Main GUI screens

The user interface (GUI) of EM3D is divided into three main windows. The upper left element (window) shown in Figure 5-11, repeated in Figure 5-12, is the main control window for the application. Data acquisition is controlled with the buttons in the “Acquire” frame. Access to the system configuration parameters is made through the “Show Setup” button. The current root filename prefix displayed and can be altered in the “File Name” frame. The system configurations can be managed with the pull-down box in the “Job” frame. The remaining controls provide access to functionality not typically used in MP System surveys. To verify the system configuration parameters are correct, press the “Show Setup” button. The main window will expand to what is shown in Figure 5-13 (left).

Figure 5-12 – EM3D Main Control Window

29

Figure 5-13 – (left) EM3D Main control window expanded to show settings, and (right) Acquisition parameters window

The series of yellow buttons in the “Setup” frame in the lower left provide access to the configuration of individual subsystems of EM3D. First, press the “Q” button or “Acq Params” to access the EM3D Acquisition Parameters. These parameters control the acquisition of the TEM data. Figure 5-13 presents graphically the expected configuration for using the MP System in dynamic mode. The “Mode, Time, and Gates” frame is where the primary configuration is made. Radio buttons provide the selection of Full Wave, Raw Decays, and Gated Decays mode. As discussed in Section 2.1.1, data collection in Full Wave mode can results in some 50,000 data points per transient per transmitter firing and records data throughout the transmit cycle including the transmitter on-time. This mode is typically only used for diagnostics. Raw Decays, as the name suggestions, provides a single decay transient per receiver per transmitter firing. These decays are arithmetically combinations of the positive and negative polarity transmitter firings within a transmit waveform. While these decays have the highest fidelity, they are also as large as 12,500 points and typically only used for diagnostics. The final mode, Gated Decays, bins the data into “windows” with a fractional width assigned in the “Gate Width (%)” value text box. Gated Decays mode is typically used with gate widths of 5% for cued data and 20% for dynamic. The delay between the transmitter turn off and the start of data acquisition, or hold off time, is displayed in the “Hold Off (us)” value text box. For TEMTADS systems, a value of 50 µs is used.

The remaining two settings in the “Mode, Time, and Gates” frame control the recorded decay time and the number of repetitions (stacking) performed. The “Decay (ms)” pull-down box lists the available decay times. This value is for a single decay recorded from a single transmitter. The value of the “Time Total (s)” sets the time required to fire all transmitters for the configured decay time. The text boxes below calculate the effect of the above settings and serve as a cross check that the settings are correct. In the example shown in Figure 5-13 (right), a decay time of 2.78 ms is selected and a total time of 130 ms. With the assumed duty cycle of 50%, the time required for a transmit cycle at 2.78 ms is (4 * 2.78 ms) = 11.12 ms. Three stacks are desired for

30

a small amount of signal averaging, or 33.36 ms. The MP system has 4 transmitters, so (4 * 33.36 ms) = 133.44 ms, as indicated. The check value of “NStacks/Tx” confirms 3 stacks will be made. The combination of the 50 ms Hold Off Time and the 2.78 ms decays results in 19 gates (“N Gates” in the display). The available choices for decay time are 0.93, 2.78, 8.33, 25, 75, and 225 ms.

The “Survey Type” frame is where the survey mode can be configured. This will typically be set to “Dynamic” for the MP System, since cued mode surveys are typically done using the TEM Datalogger software. Cued mode data collection can be done using the “Static” setting. The “Static MultiPt” mode can be used for data collection where multiple soundings are recorded for a single flag position. The contents of the “Select Transmitters” frame are populated from the system configuration file (*.ini), which will be discussed below. Transmitters which are colored green will be included in the transmit cycle, ones colored red will not be. Transmitters can be individually toggled on or off by clicking on the corresponding button. The “All” button will select all transmitters and the “Off” button will deselect all transmitters.

The “File Names and Folder” frame is where the location for saving data files is defined and the convention used for generating filenames is set. The current location for saving data files is shown in the “Storage Folder” value text box. The ellipsis “…” button to the right can be pressed to select another folder location.

NOTE: Standard practice is to not modify the output data file location, but to rather gather the files at the end of each day and place them in a new subdirectory with a useful name such as the day’s date.

The pull-down box for the “File Naming Method” indicates the current method. Press the down arrow to open the pull-down list and select the desired method. The choices are: “As Shown”, “Incremented Numbers”, and “No File Saved”. For “AsShown,” the filename typed in the filename text box on the main screen is used. For “NoFileSaved,” no file is saved. The default for the MP System is “IncrementedNumbers” which take the contents of the main screen filename textbox as a prefix and automatically append numbers starting at “00001” and incrementing by one.

The “After Acquisition” frame activates several available post-acquisition activities. These features include: inversion of the collected data set, export of the collected data set to non-.tem file formats, plotting of the collected data set, and processing through Dartmouth’s Joint Diagonalization routines. None of these features are typically used with the MP System and should not be checked (activated).

Returning to the main screen by clicking on the “X” in the upper right of the window.

The GPS input parameters can be viewed and modified by pressing the “G” button or “GPS”. These parameters configure the expected GPS input stream for processing. Figure 5-14 (left) shows the GPS configuration screen upon entry with GPS input turned off. This is the likely state to find EM3D in if the expected GPS / COM port configuration was not found on

31

application startup. Figure 5-14 (right) shows the same window with a valid configuration and a GPS connected. The “GPS On” checkbox enables EM3D to listen for incoming GPS data when checked and disables the feature when unchecked. There are also two pairs of radio buttons on the top row of the “GPS” frame. “Free Run” is the default setting which allows GPS packets to be received and processed as they arrive. “Triggered” enables a specialized mode where the DAQ computer can send a trigger pulse to the GPS receiver to provide a location measurement at that specific point in time. This mode is not typically used.

The “GPS Receiver and Port” frame is where the type of NMEA input string, computer COM port, and baud rate are set. For the MP System, the GPS is typically connected to COM1 at 115,200 Baud, as shown in Figure 5-14. The supported “Receiver ID” values are “Gpgga”, “Gpggartk”, “Ptnlggk”, “SpglE500E”, or “None”. The default select for the MP System is “Gpggartk”, which is a higher precision version of the original $GPGGA NMEA string. In the “UTM Zone” frame, how the EM3D software handles the conversion of latitude and longitude to UTM grid coordinates can be set. The options are: “Auto” or “Manual”. If “Manual” is selected, a N/S-qualified UTM Zone must be entered, “18N” for example. The conversion is handled by the software library DotSpatial13. If the system is being used in Hawaii, select the checkbox labeled “Hawaii” to use the correct projection. Once properly configured, the fields in the bottom half of the screen will populate with values for verification purposes, as shown in Figure 5-14 (right).

Figure 5-14 – EM3D (left) GPS configuration, (right) GPS configuration with serial flow enabled

Note: It is best to run serial devices at as high a baud rate as possible to reduce the total amount of time the computer spends receiving to the packet and potentially not doing other tasks.

When configuration is complete, press the “OK Done” button in the upper right to close the window.

13 http://dotspatial.codeplex.com/

32

Returning to the main screen, the IMU input parameters can be viewed and modified by pressing the “O” button or “AHRS”. These parameters configure the expected IMU input stream for processing. Figure 5-15 shows the IMU configuration screen upon entry with IMU input turned on. IMU data input can be disabled via the “Sensor On” checkbox, much like as discussed above for the GPS. The standard configuration for the MP System is shown in Figure 5-15. For the MP System, the Lord Microstrain 3DM-GX3-25 is the default AHRS sensor. The IMU is typically connected to COM2 on the DL2 and configured for 115,200 baud. When properly configured and enabled, the “Current Data” frame will be populated with the current orientation values. The raw binary string is shown in the “Raw1” value text box. The heading, or Yaw, referenced to magnetic North, Pitch, and Roll angles are shown in their respective value text boxes. The “Mag Declination” value text box may either be left at “0” which applies no correction, or set to the correct regional magnetic declination. This value is only used in the Map display and any real-time inversions. The value is noted in the saved data file in the acquisition parameters, but is not otherwise used. The “Raw Data Processing” frame allows configuration of how the AHRS data packets are handled. The options are: “Most Recent”, “Average Between Reports”, and “Filter and Report Filtered”. The default is to report the most recent value. At 10 Hz, the recommended data rate, there is approximately 1.3 AHRS packets per TEM data packet and averaging is unlikely to help. A time constant is required for the Filter option.

Figure 5-15 – EM3D IMU configuration with serial flow enabled

33

Note: It is best to run serial devices at as high a baud rate as possible to reduce the total amount of time the computer spends receiving to the packet and potentially not doing other tasks.

The supported AHRS types are: the Crossbow CXM54314, the Microstrain 3DM-GX115, the Microstrain 3DM-GX3-25, the Xsens Mti16, and None. A second orientation sensor can be configured in a similar fashion, with the same configuration options. There is no display for the outputs of the second orientation sensor.

When configuration is complete, press the “OK Done” button in the upper right to close the window.

Returning to the main screen, the data acquisition systems configuration parameters can be viewed and modified by pressing the “INI” button or “DAQ”. Figure 5-16 displays the currently loaded configuration. This information is stored in a Windows configuration file (.INI) located in “C:\Program Files (x86)\GGSciences\EM3D 2013\”. The standard MP System configuration is detailed in Appendix D.2. The typical user should not be required to edit these values as they define the geometry of the transmitter and receiver coils and the electronics configuration of the DAQ. The buttons in the lower right provide the ability to load, save, and restore default settings.

14 Obsolete unit, data sheet available at http://www.willow.co.uk/CXM543_Users_Manual.pdf 15 http://www.microstrain.com/inertial/3DM-GX1 16 http://www.xsens.com/products/mti/

34

Figure 5-16 – EM3D DAQ .INI File View Window

Press the “OK Done” button in the lower right to close the window.

The remaining Setup features, Inversion and Background are accessed via the “I” and “B” buttons. These features are not typically used in the MP System and are not discussed further in this manual version.

Press the “Hide Setup” Button to return the main window to its normal, collapsed mode.

35

6.0 IMU INSTALLATION ORIENATION TESTING

It is recommended that the installed orientation of the IMU is verified prior to commencing data collection. While the Orientation serial data flow is turned on in TEM Datalogger, as shown in Figure 5-8 and discussed in the associated text, it is possible to verify the correct orientation. To do so, remove the mounting bolts for the IMU. Facing the direction of travel, rotate the IMU (or cart) around the along-track axis to produce a positive ROLL as shown in Figure 6-1. Verify that the data acquisition system records a positive ROLL, Figure 6-2. Standing on the side of the sensor with the direction of travel to your right, rotate the IMU around the cross-track axis to produce a positive PITCH as shown in Figure 6-1. Verify that the data acquisition system records a positive PITCH, as shown in Figure 6-3. Looking down on the sensor from above, rotate the IMU around the vertical axis to produce a positive YAW as shown in Figure 6-1. If any of these checks do not give the correct response, reorient the IMU on its mount and repeat the test.

Figure 6-1 – Positive ROLL, PITCH, and YAW rotations of the IMU

36

Figure 6-2 – System displays a Positive ROLL angle for the IMU

Figure 6-3 – System displays a Positive PITCH angle for the IMU

37

7.0 SENSOR FUNCTION TESTING

Given the complicated nature of interpreting multi-static TEM data from systems like the MP System, a common question from field crews is “How can I tell the system is working?” To help answer that question, a Sensor Function Test functionality was implemented. This test allows the operator to get a non-ambiguous, first-order Yes/No answer for this question. There remain a large number of caveats that must be explored by the QC/QA data analysis chain. Since dynamic and cued data collection use different data acquisition parameters, this test should be run for each relevant set of conditions.

In preparation for each sensor function test, use the [Setup] tab in TEM DataLogger or TEM Tablet applications to set the correct data acquisition parameters for the survey you are planning. The easiest way to accomplish this is to use the [Standard Cued] or [Standard Dynamic] buttons, Figure 7-1 and Figure 7-2 respectively. The standard parameters are listed in Table 7-1.

Figure 7-1 – Standard acquisition parameters for cued surveys

38

Figure 7-2 – Standard acquisition parameters for dynamic surveys

Table 7-1 – Standard data acquisition parameters

Parameter Cued Survey Dynamic Survey Acq Mode Decimated Decimated Gate Width 5% 20%

Stacks 18 1 Repeats 9 3

Stack Period 0.9 0.033 Hold Off Time 50 µs 50 µs

The sensor function test compares the background-subtracted TEM response for a known target against a reference response recorded with the same combination of hardware and data acquisition parameters. If the reference response stored on the systems for the combination of hardware and data acquisition parameters you are using is available, the [Sensor Function] tab will be available in the TEM DataLogger or TEM Tablet applications. Access that tab to perform a sensor function test.

Position the sensor in a spot known to be clear of buried metal. Often the clear position in the IVS will be the best choice. Specify a filename and collect a background measurement from [Sensor Function] tab of the data acquisition software by pressing the “Collect Null” button, as shown in Figure 7-3. The data acquisition cycle will commence and when completed, the display will look similar to the one shown in Figure 7-4.

39

Figure 7-3 – TEM Tablet Sensor Function tab, ready to collect a background

Without moving the sensor, mount the chosen test item in same location as was used for the reference measurement. For example, the small ISO80 shown in Figure 7-5 (right) is placed in the hole on the top of the sensor housing.

Collect sensor function data by pressing the “Sensor Function” button, shown highlighted in Figure 7-4. Entry of a filename is not required as the same root filename as was used for the background measurement is used and the suffix “_sf” is appended. If the results agree with the reference values, a green LED is displayed as shown in Figure 7-5 (upper right). If they do not agree, a red LED is displayed and a summary of the incorrect results is displayed as shown in Figure 7-5 (lower right).

When done with the sensor function test, return to the [Settings] tab and ensure that the correct data acquisition parameters are set. Then if collecting cued data, select the “Data Collection” tab to return to the main screen. Otherwise exit the TEM DataLogger or TEM Tablet applications and open EM3D on the DL2.

40

Figure 7-4 – TEM Tablet Sensor Function tab, ready to conduct a Sensor Function Test

Figure 7-5 – Test item positioned for a sensor function test (left panel) and examples of the test results (right panels)

41

8.0 DYNAMIC DATA COLLECTION

In dynamic mode, the MP System is operated directly via RDP. To collect dynamic data, open and RDP connection to the DL2 and launch the EM3D application on the desktop, shown highlighted in Figure 8-1. The main screen is shown in Figure 8-2.

Figure 8-1 – DL2 Desktop with the EM3D application icon highlighted

Once the system is up and running, the basic data collection pattern is to collect data in a series of closely-spaced, parallel lines until the entire survey area is covered. A line spacing of 40 cm is recommended for the MP System, but at the operator’s discretion, this spacing can be widened somewhat if small items, such as 20mm Projectiles, are not part of the targets of interest list. It is recommended to store each line in its own data file to minimize the potential for any data issue impacting a large section of data. The recommended method for maintaining the line spacing is to stake out strings 1.2 m apart across the survey area and use the strings as guides, as shown in Figure 8-3.

42

Figure 8-2 – EM3D Main Screens at Startup

Figure 8-3 – System and Operators Collecting Dynamic Data

43

The EM3D application has several mechanisms for providing QC feedback to the operators. Referring to the “Show / Hide Windows” frame in Figure 8-4, the following displays are available: the data table, the “dancing arrows” display, a moving map, and a TEM data plot windows. The moving map and TEM data plot displays present a significant load on the system and should not be used in dynamic mode on the MP Sytem. The Data Review feature, “R,” is not current used for the MP System. The Export, Batch mode feature, “X,” should not be used for the MP System as the output file format is not currently compatible with Oasis montaj’s UX-Analyze Advanced module. The ConvertTEMTADS program discussed in Section 10.2 should be used instead.

Figure 8-4 – EM3D Main GUI with Setup Shown

The Data Table feature can be toggled on and off by the “D” button. For the MP System, the default is for the Data Table to be enabled. There are three modes for the Data Table, selected via a set of radio buttons: Navigation, AcqParams, and Acquire Data. The Acquire Data mode is the recommended mode. In this mode, the GPS fields (GPSQ, GPSUtc, LocalX, and LocalY) can be used to monitor the status of the GPS receiver and radio link. The IMU field (Heading, Pitch, and Roll) can be used to monitor the status of the IMU. The remaining fields provide insight into the status of the DAQ computer. When collecting data, the point numbers should be incrementing smoothly and the buffer usage should remain small (<1%). The TxCurrent field can be used to monitor the state of the transmitter battery. The operators should develop a site / project specific threshold for transmitter current to identify the time to change the transmitter battery. An initial recommendation is 5.5 Amps.

44

Figure 8-5 – EM3D Data Table with Three Modes Shown

The “Dancing” Arrows feature can be toggled on and off by the “A” button. For the MP System, the default is for the Arrows to be enabled. Figure 8-6 shows a significant target placed over sensor #3, a small ISO80 placed directly above the receiver cube center. For the MP System, use of the arrows is recommended only as a visual diagnostic that the EMI sensors are responding to external stimulus.

Figure 8-6 – EM3D “Dancing” Arrows with a significant signal present over sensor #3

Press the “Hide Setup” button to minimize the main window to look like the one shown in Figure 8-7.

45

Figure 8-7 – EM3D Main Screens Ready to Collect Data

To start data collection, the operators should move the beginning of a survey line. When in position, the operator with the tablet should verify the GPS and IMU status. Then the tablet operator should start data acquisition by green “Acquire” button in the main window, as shown in Figure 8-8. The tablet operator should verify that all of the parameters in the Data Table continue to look correct and that the Arrows display is reasonable. Then the tablet operator should indicate to the cart operator to move forward. The recommended walking pace is 0.75 m/s to maintain a reasonable down-track data density. The tablet operator should continue to monitor the displays until the cart operator has completed the line. Then the tablet operator should stop acquisition by pressing the red “Stop” button, as shown in Figure 8-9. Repeat the process until the survey of the area is complete or it is time for an operator rest break.

Figure 8-8 – EM3D Main Screen Ready to Collect Data

46

Figure 8-9 – EM3D Main Screen While Collecting Data

NOTE: It is currently possible to crash EM3D by pressing the “Start” button twice in a row before pressing “Stop”. Exercise caution to avoid this situation.

47

9.0 CUED DATA COLLECTION

While it is possible to operate the MP System directly via RDP, a local application on the tablet PC provides much of the same functionality and is designed for stylus-free use of a touch screen. For example, an easy-to-use, on-screen keyboard is provided for filename entry. To launch the local application, minimize or close the RDP session on the tablet. Launch the TEM Tablet application on the desktop, shown highlighted in Figure 9-1. The main screen is shown in Figure 9-2.

Once the system is up and running, the basic data collection pattern is a) to collect an initial background measurement to use for background subtraction, b) the collection of cued data for a series of flagged anomaly locations, and c) the occasional collection of additional background measurements as dictated by site conditions.

Figure 9-1 –Tablet PC Desktop

To collect a background measurement, the cart operator places the sensor cart over a known anomaly-free spot. To enter a filename for a data collect (background or data), the tablet operator touches the filename textbox, highlighted yellow in Figure 9-3. The on-screen keyboard will open and the filename can be entered. Once “OK” is pressed, the keyboard closes and the main screen returns with the filename populated, as shown in Figure 9-5. The application suite provides the functionality to display data as either current-corrected voltages (mV/Amp), or with a background measurement subtracted. This functionality is controlled by the “Collect Null” checkbox on the main screen and the associated settings on the “Setup” tab.

48

Figure 9-2 – TEM Tablet Main Screen at Startup

Figure 9-3 – Filename Textbox Location on TEM Tablet Main Screen

49

Figure 9-4 – Filename Entry Keyboard with Filename “010” Entered.

Figure 9-5 – TEM Tablet Main Screen with Filename Entered

To collect a data set as a background, press the “Collect Null” button. The button text will change to “New Null” after the first null has been collected. If the entered filename already exists, an error message will appear and the operator will be prompted to enter a new filename. A “_b” will be appended to any file collected as a background. The background will be subtracted from all plotted data going forward until another background is collected or the program is restarted. To collect a data set for a target, press the “Collect” button. Both the “Collect” and “Collect Null” buttons are highlighted yellow in Figure 9-6.

50

Figure 9-6 – TEM Tablet Main Screen with Data Collection Button Locations Highlighted

Figure 9-7 is a screenshot of the display after the location and orientation averaging is complete. Location and orientation data are averaged for 2 seconds and stored in a text file with the same filename as the TEM data and a “.gps” extension. While averaging is ongoing, a running count of the number of data packets received is displayed in the lower left of the screen, highlighted in red. In this example, the data are collected as background. The data rates for the both the GPS and the IMU are 10 Hz, with the expectation of receiving 20 samples in 2 seconds. The GPS count is 20 and the IMU count is 18, indicating that the number of data packets were received from both systems. A small fraction of the IMU packets are received with failing checksums. The loss of 1-5 packets is typically acceptable. Repeated loss of half or more should initiate a troubleshooting session. In the lower left of the screen, the status has changed from “Collecting Location and Orientation” to “Acquiring … as a Null.” In Figure 9-7 the blue square in the upper left (highlighted in yellow) indicates that data for Sensor 1 is being acquired. This will change to a sensor reading when acquisition is complete and the blue square will move to the next block in the schematic.

51

Figure 9-7 – TEM Tablet Main Screen at Beginning of Data Collection Cycle

The results of a typical background measurement are shown in Figure 9-8. The upper left corner displays a schematic of the array. The raw voltage value for the monostatic, vertical-axis receiver value corrected for transmit current for the first usable decay time gate, gate 18 typically, are shown. If the transmitter battery is not attached, the reported transmit current will be zero (0) Amps. If a receiver cable is disconnected, the decay values will be near zero voltage (0.00). For a good background shot, all gate 18, Rz(18), values will be around 25 mV/A. Increasing response results in a more negative response. Strong signals will lead to negative voltages. The right side of the screen displays the monostatic decay curves for each receiver cube. These responses are color-coded to indicated which receiver axis is which, red, green, and blue for the z,x,y axes, respectively. The absolute values of the decay curves are displayed on log-log scales. The remaining portion of the screen contains the system controls.

When data collection is complete, the status bar on the bottom of the screen will be updated to indicate the last filename used and filename and collection time of the last background, as shown in Figure 9-8.

52

Figure 9-8 – TEM Tablet Main Screen with Typical Background Data Presented

To conserve WiFi transmission bandwidth, only a subset of each decay is sent to the TEM Tablet application. A sparsing factor of 4 is typically used, or every fourth data point in each decay is transmitted. This factor can be configured on the TEM Datalogger Setup Tab (See Figure 5-5). For comparison, a representative set of background data displayed by the TEM Datalogger application is in Figure 9-9 with the complete decays shown.

Throughout data collection, it is the responsibility of the operator to monitor the GPS and IMU status. In the bottom left of the screen, an LED is shown for each sensor. If data packets are being received and parsed, the LED (highlighted in red in Figure 9-8) will be colored green. While TEM data is being collected, the location and orientation sensors are switched off and therefore the LEDs will be colored gray to indicate that they are inactive. If location and orientation data are expected and not being received, the LEDs will be colored red.

Additionally, once a second, the GPS position in UTM (meters) will be displayed along with the GPS fix quality (FQ), the number of GPS satellites in view (SV), and the appropriate Dilution of Precision (DOP, HDOP for $GPGGA and PDOP for $PTNL, GGK). The IMU Yaw value will be updated and displayed once a second in the bottom right of the screen. If the IMU data packet is invalid (bad checksum), the status code “777” will be displayed.

53

Figure 9-9 – TEM Datalogger Main Screen with Typical Background Data Presented

A new background measurement should be made every 30 – 90 minutes, depending on site conditions. If the temperature and relative humidity are relatively constant, every 60 – 90 minutes is sufficient. If not, more frequent backgrounds are recommended.

Measurements over a target take approximately one minute, and a typical survey hour can cover 35 – 40 anomalies if inter-anomaly spacing is favorable. An example of a standard target, a 4-inch diameter Aluminum sphere is shown in Figure 9-10. The Aluminum sphere was located under the center of the array on the ground, for an effective depth of -5 cm.

At this point, the data collection operator might be considering moving the sensor array over to better capture the target which appears to be far off from the array center. As the EMI response of a target is both a function of the intrinsic target parameters (size, shape, material composition, etc.) and extrinsic properties (sensor – target relative orientation and location), it is possible for the operator to misinterpret the results. As such, the ability to conduct a ‘quick and dirty’ inversion is provided. Once the data collection cycle is complete (as shown in Figure 9-10), the operator can press the now-active “Invert” button, highlighted in yellow. After a few seconds, the results of a single-dipole inversion are shown on two tabs. The first tab, “Location,” shows the inverted position of the item with respect to the array as shown in Figure 9-11. The target is represented by a circle with a cross through it, shown highlighted yellow in Figure 9-11. The target fit depth and radial offset are printed in the upper left of the tab. The relative cart orientation is indicated by showing the location of cart handle in the figure. As expected, the inverted position of the sphere is roughly -5 cm (depth -7 cm) and roughly centered (offset 2

54

cm). If the second tab, “Polarizabilities,” is selected, the calculated principal polarizability decays are shown as seen in Figure 9-12. As expected for an item with spherical symmetry, the three principal polarizability decays are equal.

In Figure 9-13, an example for a small ISO80 positioned under Sensor #1 (refer to Figure 3-1 for sensor locations and ID #’s). As expected, the strongest z-axis response is from Sensor #1, with weak responses from Sensors #2 and #4 and little response from Sensor #3. TEM data are stored in the designated location with the fully-populated version of the anomaly number provided (Site_Subsite_AnomalyID) with at “.tem” file extension.

The target fit depth and radial offset are printed in the upper left of the tab. The relative cart orientation is indicated by showing the location of cart handle in the figure. As expected, the inverted position of the ISO80 is roughly 0 cm, or on the surface (depth -2 cm) and offset under sensor #1 (offset 30 cm). If the second tab, “Polarizabilities,” is selected, the calculated principal polarizability decays are shown as seen in Figure 9-15 for a small ISO80. As expected for an item with axial symmetry, the principal polarizability decays sort out into one large and two smaller, and equal ones. When the operator is done with the fit results tabs, pressing the “Hide” button, highlighted in Figure 9-15, or collecting a new data set will return the view to the standard data view.

The operator has the ability at any time during the data collection process to record field notes regarding any anomaly by pressing the “Note” button, highlighted in yellow in Figure 9-16. When the “Note” button is pressed, the “Field Notes” dialog will open, as shown in Figure 9-17. If a data file has been collected, the current anomaly ID will be taken from the filename textbox on the main data collection panel and prepopulated into the “Notes for Anomaly” textbox. Up to six preselected data quality conditions are prepopulated into large buttons to allow the operator to quickly indicate a data quality condition without requiring typing. These conditions are read from the file “TEM_DataLogger_Notes.ini” stored in the application execution directory. The file is written in plain text and can be modified to suite the current situation. If there is additional information required or none of the button captions applies, the operator can press the comment area (the large textbox in the middle of the screen). An on-screen keyboard will open and the operator can type a comment, as shown in Figure 9-18. Press “OK” to return to the “Field Notes” dialog.

55

Figure 9-10 – TEM Tablet Main Screen with Standard 4-inch Al Sphere Data Presented

Figure 9-11 – TEM Tablet Location Screen with Data Presented for a Standard 4-inch Al Sphere

56

Figure 9-12 – TEM Tablet Polarization Screen with Data Presented for a Standard 4-inch Al Sphere

Figure 9-13 – TEM Tablet Main Screen with Data Presented for a Small ISO80

57

Figure 9-14 – TEM Tablet Inversion Location Screen with Data Presented for a Small ISO80

Figure 9-15 – TEM Tablet Inversion Polarization Screen with Data Presented for a Small ISO80

58

Figure 9-16 – TEM Tablet Main Screen with the Note Button Highlighted

Figure 9-17 – TEM Tablet Field Notes Dialog

59

Figure 9-18 – TEM Tablet Field Notes On-Screen Keyboard

Figure 9-19 shows the “Field Notes” dialog with the “Data Issues” button pressed and a comment entered. When the operator presses “Save”, this information is stored in a text file with the same filename as the TEM data and with the extension “.txt”.

Figure 9-19 – TEM Tablet Field Notes Dialog Filled Out

60

10.0 DATA HANDLING

10.1 DATA TRANSFER

TEM data is stored on the computer hard drive in the G&G Sciences’ proprietary “.tem” format. Location and orientation information for cued data are stored in plain-text files with the extension “.gps” and “.txt”, respectively. To download data, restore or reopen the RDP session on the tablet PC to the DL2. The .tem, .gps, and .txt files can be copied to a USB key or hard drive. The storage device needs to be directly plugged into DL2, as shown in Figure 10-1.

Figure 10-1 – DataLogger2 Rx Interconnect Panel with USB Key Inserted for Data Transfer

10.2 DATA CONVERSION

Data analysis tools such as Geosoft’s Oasis montaj are typically not able to read the binary .tem files produced by TEM Datalogger or EM3D directly. The performance of the UX-Analyze Advanced package for Oasis montaj is much improved if several pieces of metadata (e.g. data collection time) are injected into the TEM data structure prior to import. For the Geometrics MetalMapper systems, a tool provided by Snyder Geoscience, TEM2CSV, provides this functionality as part of its feature set. For the TEMTADS MP 2x2 Cart, this functionality is provided by the ConvertTEMTADS application. This program is designed to be run on the data analyst’s computer, not the DL2. An installer for the current version of the application is available online to download.17 Once installed and the data are copied to the data analyst’s computer, start the application. The initial screen is shown in Figure 10-2. The only user configurable setting is to include the data collection date in the .csv or not, controlled by the “Add Date” checkbox. By default the date should be included.

17 http://www.squeakthump.org/dataexchange/ConvertTEMTADS/

61

Figure 10-2 – ConvertTEMTADS Main Screen

To start the conversion process, press the “select .tem files” button. The file selection dialog will open as shown in Figure 10-3. Select one or more .tem files for conversion and press “OK” to continue. When the main screen opens again, press the now-active “convert to .csv” button. The program will indicate progress file by file by displaying the filename on the screen. When all conversions are complete, the message “Conversion Complete” will be displayed, as shown in Figure 10-4. The .csv files are now created and ready for import into data analysis tools.

Figure 10-3 – ConvertTEMTADS Select File Dialog

62

Figure 10-4 – ConvertTEMTADS Main Screen After Conversion is Complete

11.0 SYSTEM SHUTDOWN

11.1 SYSTEM SHUTDOWN

If collecting cued data, close the TEM Tablet application on the tablet PC. If necessary, maximize or reopen the RDP session from the tablet PC to DL2. Close the TEM DataLogger or EM3D application. Press and hold the “shutdownow.bat” batch file (highlighted yellow in Figure 11-1) on the computer’s desktop. When the contextual menu opens, select “open”. The DL2 will commence its shutdown procedure. When complete, the RDP session will close and the green power light on the Rx Interconnect panel will go dark. The DL2 is now off and the Main On/Off switch can be moved to the “OFF” position where the red light is off.

11.2 TABLET SHUTDOWN

Shut down the tablet PC with the Windows 7 standard Start Menu / Shutdown procedure. When the blue power LED is dark, the tablet is shut down.

11.3 DISCONNECTING BATTERIES

The final shutdown step is to disconnect and remove the two UBI-2590 batteries in the backpack. First disconnect the Tx PWR cable from the battery. Disconnect the CPU PWR cable from the battery. Place both UBI-2590 batteries on a charger when available. Connect the tablet PC to its wall charger.

63

Figure 11-1 – Desktop of the DataLogger2 Computer with the Shutdown Batch File Highlighted

64

12.0 SYSTEM DIAGNOSTICS

An important part of operating an advanced EMI sensor system is in ensuring that the system and all of its subcomponents are fully functional and providing the field team with the confidence that they can know that the system is fully functional. In this Section, the main problem indicators that the software provides to warn the operator of detectable issues are discussed along with several simple checks that the NRL team has found useful for diagnostics and troubleshooting.

12.1 LOCATION AND ORIENTATION INDICATORS

Starting with application start, TEM Datalogger and TEM Tablet both provide status indications for Location and Orientation sensors. These indicators are shown across the bottom of the main screen, as shown in Figure 12-1. For these examples, the system is shown with both GPS and IMU enabled. If either is disabled, the corresponding indicators will not be shown.

In Figure 12-1, the system is shown in a functioning state. The two LEDs in the lower left-hand corner indicate that data packets are coming from each system by coloring the LEDs green. If data flow ceases, the LEDs will turn red. During TEM data collection, the serial ports are explicitly closed, shutting off data flow. During this period, the LEDs will be colored gray. In the bottom center portion of the screen, additional GPS status data is shown. The three colored textboxes indicate the GPS fix quality (FQ), number of GPS satellites (SVs), and the appropriate Dilution of Precision (DOP).18 The $GPGGA NMEA sentence provides horizontal DOP values (HDOP). The vendor-specific $PTNL, GGK NMEA sentence provides positional (3D) DOP values. The background color of these textboxes indicates the status of the numerical values displayed. The FQ textbox is colored green with the FQ indicates RTK fixed, yellow for RTK float, and red for all other values. If the number of GPS satellites is 5 or greater, the textbox background is green, otherwise it is red. If the DOP value is less than or equal to 4, the textbox background is green, otherwise it is red. The final two GPS status indicators are the UTM Northing and Easting values (in meters), as calculated from the latitude and longitude values from the data packet.

In Figure 12-2, the main screen is shown after the GPS receiver has been unplugged. This is demonstrative of a dead GPS battery or broken serial cable. The GPS LED has turned red to indicate that data packets are not arriving. The contents of the GPS status textboxes are cleared and filled with dashes, as further indication that GPS data packets are not being received.

18 http://en.wikipedia.org/wiki/Dilution_of_precision_%28GPS%29

65

Figure 12-1 – TEM Datalogger Main Screen at Idle

In Figure 12-3, the response when the RTK is degraded by covering the GPS antenna is shown. The GPS status values are out of tolerance, and the textbox backgrounds are colored red. The GPS LED is colored green because data packets are being received. GPS status values, along with UTM Northing and Easting values, continue to update as data, albeit bad data, is being received.

If the IMU is being used, the IMU LED will be colored green if data packets are being received. Figure 12-4 shows the system response to the IMU power being unplugged. As data packets are not being received, the IMU LED turns red and the contents of the “Yaw” is cleared. If the checksum on the IMU data packet does not verify, a value of “777” is displayed for the Yaw, as shown in the Yaw textbox. Bad packets (invalid checksum) will not be included in any collected data. As an example, Figure 12-5 shows the data collections screen post-collection of the location and orientation data. The count of IMU data packets is 0, as expected and the reported Yaw value is replaced with dashes.

66

Figure 12-2 – TEM Datalogger Main Screen with the GPS Receiver Unplugged

Figure 12-3 – TEM Datalogger Main Screen with RTK Degraded

67

Figure 12-4 – TEM Datalogger Main Screen with the IMU power unplugged

Figure 12-5 – TEM Datalogger Main Screen During Data Collection with the IMU power unplugged

68

12.2 TEM DATA DIAGNOSTICS

There are two main components to ensure that the MP System is fully operational from a field QC perspective, evaluation of background response and stability and exercising all receiver channels to ensure connectivity and proper operation. This section will lay out several diagnostics tests that the NRL team has found to be useful for this purpose and for troubleshooting. It is recommended to either run these tests directly on the DL2 or to decrease the sparsing factor for the tablet to “1” from “4” to observe sufficient detail.

The results of a typical background measurement are shown in Error! Reference source not found.. The upper left corner displays a schematic of the array. The current-corrected voltage (mV/A) for the monostatic, vertical-axis receiver decays for the first usable decay time gate, gate 18 typically, are shown. The right side of the screen displays the monostatic decay curves for each receiver cube. These responses are color-coded to indicated which receiver axis is which, red, green, and blue for the z,x,y axes, respectively. The absolute values of the decay curves are displayed on log-log scales. Increasing response results in a more negative response. Strong signals will lead to negative responses.

Figure 12-6 – TEM Datalogger Main Screen with Typical Background Data Presented

Two numerical values are overplotted on the decay curves. The first is the background-subtracted, current-normalized decay value for the first usable time gate, Rz(18). If the measurement was collected as a background, the values are obviously not background subtracted. In this case, the values reported on the decay plots and in the array schematic will

69

agree. For background subtracted cases, they will not. If a receiver cable is disconnected, the non-background subtracted decay values (shown in the array schematic) will be near zero voltage (0.00).

The z-axis response (red) will be the strongest with typical Rz(18) values of +20-30 mV/A. The z-axis response will show two sharp peaks. These peaks actually reflect sign changes in the data (i.e. + to – or – to +). Since the plots are of absolute values, they show as peaks. Both peaks should be present, one at early time and one at late time. The x- and y-axis responses should be two decades smaller (100x) and relatively flat with time. A slight decay is often observed.

The second value is the peak transmit current for the transmit cycle corresponding to the data plotted (i.e. Tx current for Tx1 is shown on the decay plot for sensor 1. The transmitter current should typically be 6.0 A or more. If the transmitter battery is not attached, the reported transmit current will be zero (0) Amps, as shown in Figure 12-7. It is recommended to terminate data collection and resolve the issue.

A final check of the background response is to monitor the reproducibility of the background response. One or more additional measurements are made of a known background area as data rather than as a background by using the “Collect” button. The results of one such using Figure 12-8. If the system is behaving well, the background-subtracted “background” response should be very small and show a small decay in time. In Figure 12-8, the Rz(18) values were ±0.35 mV/A or lower.

Figure 12-7 – TEM Datalogger Error Message for Low Transmitter Current

Once the operator is convinced the background response of the system is good, the next set of checks are to confirm that the receivers are responding correctly to an external target. When the array is cart-mounted and on its wheels, it can be difficult to properly center a target underneath the array, so a quick and easy test is to place a test object above the array where it can easily be centered. The drawback is that the inversion routines do not work with items placed above the array, so no fit results can be checked. Figure 12-9 shows the results of a data collection with a 4-inch Al sphere placed 18 cm above the array center. The z-axis decay is large and slightly larger than the x- and y- decays. The Rz(18) values are approximately equal and in the -20 – -30 mV/A range. This test indicates that all receiver channels are working.

70

Figure 12-8 – TEM Datalogger Main Screen with Background Data Collected as Data

Figure 12-9 – TEM Datalogger Main Screen with a 4-inch Aluminum Sphere Centered above the Array

71

Note: Any target can be used for these tests. It is recommended to select a relatively simple one (i.e., a sphere or a pipe section) and use the same one each time. This allows the operator to become familiar with the response of the item and enhances recognition of issues.

Placing the same sphere on the ground, roughly centered underneath the array yields approximately the same target – array separation at 15 cm.

72

13.0 SYSTEM MAINTENANCE

The contents of the electronics housing do not generally require maintenance and are not considered user-serviceable. For reference, a picture of the unit internals is shown in Figure 13-1. One should make sure that the intake and exhaust fan protection screens are cleaned periodically to prevent them from being fouled with debris. The DL2 chassis has been designed to allow easy removal of the fan screens for cleaning or replacement. Figure 13-2 shows the location of the main air inlet fan. Using a #1 Phillips screw driver, the four (4) screws holding the metal cover in place can be removed. The fan screen can then either be cleaned or replaced19 without disturbing the rest of the electronics. A second fan is located on the side of the DL2 unit above the Rx Connector Panel. This fan is the air exhaust fan and typically does not require cleaning. The exhaust fan screen is mounted with the same hardware and can be removed and cleaned/replaced in the same fashion.

Cables should be inspected routinely for wear and damage. Connectors should be checked for loosening as undesired relative motion can lead to wear and cable breakage. The cart superstructure should be examined for cracks and breaks in the plastic component. Any damage should be repaired as soon as possible. Periodically, the white “clam shell” top and bottom covers should be inspected for damage from impacts with rocks and such. Any debris or moisture buildup should be removed. If a battery fails sooner than expected, it should be marked with a piece of tape or similar and monitored for reproducibility. If the battery continues to fail, it should be replaced.

19 McMaster-Carr P/N: 19155K3, Plastic Fan Guard W/Filter, for 2.36"(60mm) Fan

73

Figure 13-1 – Internal View of the Electronics Housing

Figure 13-2 – Air Inlet Fan Cover Location Shown With Respect to Tx Connector Panel and Main On/Off Switch

74

14.0 GENERATING A SENSOR FUNCTION REFERENCE FILE

The functionality on the “Sensor Reference” tab in TEM Datalogger is driven by comparing a background-subtracted data set (background file without target and data file with target) to a known good background-subtracted data set for that same item, placed in the same location, using the same sensor and electronics. A reference file stores the known good data and must be present to access the “Sensor Reference” tab.

A generator program is provided to take the two required data files and generate the reference file. Prior to running the program, you will need to gather two .tem files: One background shot where no test item is located on top of the array, and one signal shot with the item of choice in the location you plan to use. These should be collected using the “Data Collection” tab of the TEM Datalogger application.

Prior to updating the reference file, rename the existing one. It is located at the top level of the C: drive, “C:\ TEMTADS_SensorFunctionReference_X_Y_##.csv” where “X” and “Y” are letters corresponding to the IDs of the sensors and electronics used to collect the reference data and “##” indicates the decay time, either 3 or 25 ms, respectively.

To access the reference generator software, a shortcut is typically provided in the “TEMTADS Projects” folder on the DL2 desktop. If no shortcut exists, navigate to the executable location. The executable (‘SensorFunctionReference.exe’) should be located in a location similar to:

C:\My Documents\Visual Studio 2008\Projects\TEMTADS MP\\SensorFunctionReference\SensorFunctionReference_1_1_0_Distribute\SensorFunctionReference\bin\Debug

If no shortcut is provided, add a shortcut to the application to the desktop.

Run the application. The main windows will open, as shown in Figure 14-1. Verify that the correct serial numbers are indicated for the sensors and electronics you are using, “A” for both in this case. The IDs can be found on the cart and electronics. Press the “Data .tem File” Button to load the .tem data file for the target in place. A file open dialog will open. Browse to and select the correct .tem file, as shown in Figure 14-2. Press the “OK” button to return to the main screen, which will now look like Figure 14-3.

75

Figure 14-1 – TEMTADS Sensor Function Reference Generator Main Screen

Figure 14-2 – TEMTADS Sensor Function Reference Generator File Selection Dialog

Navigate to and select the .tem file with the target present. Press “Open” to select. The application main screen will now look like Figure 14-3.

76

Figure 14-3 – TEMTADS Sensor Function Reference Generator Main Screen with Data .TEM File Selected

Repeat the process using the “Background .tem File” button to select the background file that you want to use, as shown in Figure 14-4.

Now press the “Create Reference File” button to generate the reference file. It will be written directly to its required location, the top level of the C: drive. For this example, the filename would be “C:\ TEMTADS_SensorFunctionReference_A_A_25.csv”. Verify that the new file has been written (present, has the right creation date, etc…). You are now ready to use the new target for in-the-field system response checks.

77

Figure 14-4 – TEMTADS Sensor Function Reference Generator Background Selection Dialog

Figure 14-5 – TEMTADS Sensor Function Reference Generator Main Screen with Both .TEM Files Selected

78

15.0 DATA PROCESSING

The entirety of the data processing workflow for the MP System is beyond the scope of this document. This section will provide a brief how-to tutorial for importing cued TEM data from the MP System into the Geosoft Oasis montaj environment and the UX-Analyze Advanced module for data QC purposes. The reader is referred to the UX-Analyze Advanced tutorial [11] and other training materials available from Geosoft and SAIC for further discussion.

After copying the converted data files (.csv) to a computer with UX_Analyze Advanced installed, open Oasis montaj and start a new project. Then add the UX_Analyze Advanced menu by selecting GX / Load Menu and then selecting UX-Analyze Adv.omn from the file dialog, shown highlighted in Figure 15-1. Similarly, load the IGRF menu.

Figure 15-1 – Oasis montaj Load Menu Dialogs for (left) UX Analyze Advance and (right) IGRF

Once the menus are loaded, the first step is to configure several initial settings. To do this, select UX-Analyze Adv / Settings. The dialog shown in Figure 15-2 (left) will open. Select Static and select a name for the Geosoft database (.gdb) that will contain the final results, test.gdb in this example. The anomaly window size defines the size of the anomaly maps that are generated as well as the search radius to find the associated cued data if using a target list. We recommend using the value 2. The values for the remaining fields are largely unused, the provided settings are recommended.

Prior to importing data, the magnetic declination of the Earth’s magnetic field for the survey area needs to be determined. Oasis montaj provides this capability via the IGRF / Compute Single Point GRF Values selection. When selected, the dialog show in Figure 15-2 (right) will open. The data analyst must provide the first six values and press Calculate. This will populate the remaining three values, including the magnetic declination. It is not necessary to record these values, as the magnetic declination will be automatically carried forward in the processing pipeline. Press Close to close the dialog.

79

Figure 15-2 – (left) UX Analyze Settings Dialog, (right) Compute Single Point GRF Values Dialog

The next step is to import the converted data and background files into data and background .gdb files, respectively. To begin, select UX-Analyze Adv / Import Advanced Sensor Cued Data. The dialog shown in Figure 15-3 will open. Select TEM2x2x3 as the sensor type and supply the current ride height of the sensors, 0.2m in this example. The default configuration GPS antenna position is prepopulated. Revise the values, if necessary.

Figure 15-3 – Import Advanced Sensors Dialog

Select the data files (including background files) by pressing the ellipsis next to Input .CSV file(s) and making the file selection in the dialog box that opens. Make the appropriate selection for “Survey Type.” With the exception of TEM Datalogger files pre-version 4.6.2, a flag is set in the .csv file to indicate background vs. data files. Choosing the “Automatically detected”

80

radio button will allow all .csv files to be imported in one step. Backgrounds will automatically be partitioned off into a .gdb with the same name as the data and a “_background” added. Enter the filename for the .gdb file which the data should be stored in or select an existing one via the ellipsis. Unless the individual situation requires it, select “From CSV file header” for the source of Data chip ID’s. The recommended default offset for duplicate ID numbers is 10000.

If a target list is not available, select the checkbox next to Import data chip center(s) into target database to create a target database. Target information can also be import from a .csv or .gdb source file. It is possible to import the survey data and background files separately using the same process above and two iterations with different values for “Survey type”. If this is done, it is typically not necessary to import the backgrounds into the target database.

The first data QC diagnostic is to look at the TEM decays for the background data. To do this, select UX-Analyze Adv / QC Tools / Decay Display – QC. The dialog shown in Figure 15-4 (left) will open. Ensure that the entries are correct and similar to those shown in the Figure. In particular, ensure that the sensor type is correct, the background database is correct, the option “selected-overlaid” is selected, the correct sensor data channel is selected, the correct beginning time gate is selected (14 is the recommended value), and a meaningful prefix is provided for the output. The Maps to Plot section is where the output details are selected. With 48 transmitter / receiver combinations for the MP System, selecting All Transmitters can result in an overwhelming number of maps to review, but it is the most complete view, as shown in Figure 15-5. The results are stored in the .\UXANALYZE_wrk\decay_maps subdirectory as both as .map and .png (if checked) files. The user should inspect the decays and note any backgrounds that deviate from the norm. If more than one background file is available, the variation can be explored by selecting UX-Analyze Adv / QC Tools /Calculate Background Statistics. The dialog presented is shown in Figure 15-4 (right).

81

Figure 15-4 – (left) Display Decay – QC Input, and (right) Calculate Background Statistics Dialog

82

Figure 15-5 – Display Decay – QC results plot for the Overlay-All option

83

The next step is to level, or background subtract, the data using the available background data. Select UX-Analyze Adv/ QC Tools / Level Advanced Sensor Data. The dialog shown in Figure 15-6 (left) opens. The Site database is the location of the survey data. When selected, the available data sets available to be leveled will appear in the Site lines area. A similar process is used to select the backgrounds for leveling. At this point the user can deselect any background previously noted to be problematic. Sensor channel should be populated with the array channel containing the TEM data (UXA_DATA, typically). Sensor channel suffix defines the suffix to add to the new array channel containing the leveled TEM data, typically “lev”. A proximity method should be selected. This determines which background to use to level each survey file. If “Location” is selected, the geographically nearest background spot will be selected for each survey data set. If “Time & Location” is selected, there are more options. By default, a very generous time threshold of 12 hours and no distance tolerance are selected. As the example data was collected without moving the array, a time threshold of 2 hours and no distance tolerance is appropriate. If no distance tolerance is entered the background nearest in time within the time threshold is selected. The distance tolerance sets how close two or more background points can be and still be considered the same location. Backgrounds within the tolerance are considered the same and only time is used to pick between them.

Figure 15-6 – Level Advanced Sensor Data Dialog (left), Decay Display – QC Dialog (right)

84

Next is to look at the leveled data TEM decays. To do this, select UX-Analyze Adv / QC Tools / Decay Display – QC. The dialog shown in Figure 15-6 (right) will open. Ensure that the entries are correct and similar to those shown in the Figure. In particular, ensure that the sensor type is correct, the correct sensor data channel is selected (the leveled data channel created in the last step), the correct beginning time gate is selected (14 is the recommended value), the option “selected-individual” is selected and a meaningful prefix is provided for the output. The Maps to Plot section is where the output details are selected. With 48 transmitter / receiver combinations for the MP System, selecting All Transmitters can result in an overwhelming number of maps to review, but it is the most complete view, as shown in Figure 15-7. The results are stored in the .\UXANALYZE_wrk\decay_maps/target group_prefix subdirectory as both as .map and .png (if checked) files.

Once the data are leveled and the decays QC checked, the recommended next QC step is to model the data and review the results. To model a series of targets in a batch mode, select UX-Analyze Adv /Model Targets – Batch Mode … The multi-tabbed dialog shown in Figure 15-8 and Figure 15-9 opens to Panel 1 – Survey Database (Figure 15-8 (left)). Verify that the selections are correct, in particular the sensor channel and sensor height. The sensor height channel (“Z”) is one that was populated during the data import process. Also select whether to do a single- or multi- dipole inversion via the Multiple Object Solver checkbox.

The single-dipole solver is recommended for initial QC for speed and simplicity of analysis. Moving to Panel 2 – Target Database (Figure 15-8 (right)), verify the selections and select the target range to process with the Start ID, End ID, and Mask Channel. On Panel 3 – Target Database (Figure 15-9 (left)), verify that the correct range of time gates is selected. The contents of Panel 4 – Coil Geometry (Figure 15-9 (right)) do not require confirmation or general usage.

After confirming all of the settings, press the OK button to proceed. After some processing time, the modeling results will be stored in the .\UXANALYZE_wrk\fit_results\target database_target group subdirectory as IDL save sets (.IDL) and as images (.png). The results for a shotput are shown in Figure 15-10 as an example.

85

Figure 15-7 –Decay Display – QC Results for Leveled Data

86

Figure 15-8 – Modeling Parameters – Static Survey Mode – Panels 1 and 2

Figure 15-9 – Modeling Parameters – Static Survey Mode – Panels 3 and 4

87

Figure 15-10 – Modeling Results – Shotput, Static Survey Mode

88

16.0 REFERENCES

1. MR-200909 / MR-200807 joint In-Progress Review, October, 2010.

2. “TEMTADS Adjunct Sensor Systems, Hand-held EMI Sensor for Cued UXO Discrimination (ESTCP MR-200807) and Man-Portable EMI Array for UXO Detection and Discrimination (ESTCP MR-200909), Final Report,” J.B. Kingdon, B.J. Barrow, T.H. Bell, D.C. George, G.R. Harbaugh, and D.A. Steinhurst, NRL Memorandum Report NRL/MR/6110—12-9401, U.S. Naval Research Laboratory, Washington, DC, April 5, 2012.

3. “Man-Portable EMI Array for UXO Detection and Discrimination,” T.H. Bell, J.B. Kingdon, T. Furuya, D.A. Steinhurst, G.R. Harbaugh, and D.C. George, presented at the Partners in Environmental Technology Technical Symposium & Workshop, Washington, DC, December 1-3, 2009.

4. “STANDARDIZED UXO TECHNOLOGY DEMONSTRATION SITE SCORING RECORD NO. 933 (NRL),” J.S. McClung, ATC-10514, Aberdeen Test Center, MD, March, 2011.

5. “2011 ESTCP UXO Live Site Demonstrations, Marysville, CA, ESTCP MR-1165, Demonstration Data Report, Former Camp Beale, TEMTADS MP 2x2 Cart Survey,” J.B. Kingdon, D.A. Keiswetter, T.H. Bell, M. Barner, A. Louder, A. Gascho, T. Klaff, G.R. Harbaugh, and D.A. Steinhurst, NRL Memorandum Report NRL/MR/6110—11-9367, Naval Research Laboratory, Washington, DC, October 20, 2011.

6. “2012 ESTCP UXO Live Site Demonstrations, Spencer, TN, ESTCP MR-1165, Demonstration Data Report, Former Spencer Artillery Range, TEMTADS Demonstration,” submitted August 15, 2012.

7. “2012 ESTCP UXO Live Site Demonstrations, Central Impact Area, MA, ESTCP MR-1165, Demonstration Data Report, Massachusetts Military Reservation, TEMTADS MP 2x2 Cart Survey,” in publication as NRL Memorandum Report.

8. “Source Separation using Sparse-Solution Linear Solvers,” J.T. Miller, D.A. Keiswetter, J.B. Kingdon, T. Furuya, B.J. Barrow, and T.H. Bell, Detection and Sensing of Mines, Explosive Objects, and Obscured Targets XV, Proc. of SPIE Vol. 7664, 766409 (2010).

9. TEMTADS User Manual Addendum, Version 5, G.R. Harbaugh, April 2014.

10. C.T. Love, private communication, April 16, 2014.

11. http://www.geosoft.com/resources/goto/ux-analyze-advanced

89

APPENDIX A. COMMUNICATIONS CONFIGURATION DETAILS

A.1 PHYSICAL CONNECTION

The MP System is provided with a standard VGA video connector and two USB ports. It is recommended to have a VGA monitor, a keyboard, and a mouse available (including a power source) in case of severe loss of network connectivity. One of the USB ports is used by the wireless Ethernet adapter and is generally not available. A wireless combination keyboard / mouse combination, such as the Logitech Wireless Combo Mk520 With Keyboard and Laser Mouse20, is a good choice for conserving USB port usage.

Some of the operations involving the tablet PC are facilitated by having a physical keyboard available. For these purposes, a small wireless keyboard is recommended such as the FAVI Entertainment Wireless Keyboard21.

NOTE: Electrical transients from the EM transmitter firing have a negative impact on the operation of USB keyboards attached to the system. We recommend using a wireless keyboard / mouse combination or not having the keyboard attached during transmission.

A.2 WIRED ETHERNET CONNECTION

An RJ-45 wired Ethernet jack is provided as part of the system. Communication with DL2 can be achieved using the RDP. The IP configuration of the wired connector is:

Table A-1 – DataLogger2 Wired Ethernet Address

IPAddress 192.168.1.200 Submask 255.255.255.0 Gateway and DNS N/A

Set your laptop/tablet for a different IP address in the same subdomain (192.168.1.xxx) that is not already used. A standard Cat5e Ethernet cable should be sufficient for connection, if your device’s Ethernet port can auto-negotiate. Otherwise, a cross-over Ethernet cable will be required.

A.3 WIRELESS ETHERNET CONNECTION

With the switch to Windows 7 for the DL2, the wireless networking connection is simplified. The details for the legacy configuration are retained in the next section.

20 http://www.amazon.com/Logitech-Wireless-Combo-Keyboard-920-002553/dp/B003VANO7C 21 http://www.amazon.com/FAVI-Entertainment-Wireless-Keyboard-TouchPad/dp/B003UE52ME

A-1

Rather than using an Ad Hoc WiFi configuration, the application Connectify22 is used to turn the wireless Ethernet adapter connected to the DL2 into a WiFi access point. Configuration of clients (e.g. the tablet PCs) is significantly reduced using this connection method. A different WiFi adapter is required to support this functionality, the D-Link DWA-140.

Table A-2 – Connectify DataLogger2 Wireless Ethernet Address

IPAddress 192.168.89.1 Submask 255.255.255.0 Gateway and DNS N/A SSID WhoMe2 Network Type Infrastructure Pass Phrase NRLtemtads

A.4 LEGACY WIRELESS ETHERNET CONNECTION

A Buffalo WLI-UC-GNM wireless Ethernet adapter is provided with the system. Communication with DL2 can be achieved using RDP. The IP configuration of the wireless adapter is:

Table A-3 – DataLogger2 Wireless Ethernet Address

IPAddress 192.168.1.202 Submask 255.255.255.0 Gateway and DNS N/A SSID WhoMe Network Type Ad-hoc

The wireless network is an “ad-hoc” one, rather than an infrastructure type (with access points) which is set to start immediately on system startup. The wireless network is used by the tablet computers for controlling the system. All tablets are assigned the same IP address, 192.168.1.210. The Windows XP configuration screens for the wireless networking are shown in Figure A-1, Figure A-2, and Figure A-3.

22 http://www.connectify.me/

A-2

Figure A-1 – DataLogger2 Wireless Network Configuration Screens #1

Figure A-2 – DataLogger2 Wireless Network Configuration Screens #2

A-3

Figure A-3 – DataLogger2 Wireless Network Configuration Screens #3

A-4

APPENDIX B. CABLE WIRING SCHEMATICS

Figure B-1 – Datalogger 2 Rx Connector Schematic

Table B-1 – Datalogger 2 Rx Connector Pin Out

Preamp Contact Function Wire Color Sensor #1 Sensor #2 Sensor #3 Sensor #4 Rx Board

Channel 1 B+ (Vcc) Positive Lead White s m W B - 2 RX-axis Positive Lead Red j Y V C 1 or 4 3 RX-axis Negative Lead Black (Red) i Z U D 4 RZ-axis Positive Lead Blue h a T E 2 or 5 5 RZ-axis Negative Lead Black (Blue) g b S F 6 RY-axis Positive Lead Green f c R G 3 or 6 7 RY-axis Negative Lead Black (Green) e d P H 8 B- (Vdd) Negative Lead Black (White) r n N J - 9 Ground (Vcc, Vdd, Common) Shield q p M K -

B-1

DataLogger and DataLogger 2 Tx Connector

Figure B-2 – Datalogger 2 Tx Connector Schematic

Table B-2 – Datalogger 2 Tx Connector Pin Out

20-16 Pin Function Cable Label C Sensor 1 (Tx0) Negative Lead 1 / D Sensor 1 (Tx0) Positive Lead 1 / + N Sensor 2 (Tx1) Negative Lead 2 / P Sensor 2 (Tx1) Positive Lead 2 / + S Sensor 3 (Tx2) Negative Lead 3 / R Sensor 3 (Tx2) Positive Lead 3 / + J Sensor 4 (Tx3) Negative Lead 4 / H Sensor 4 (Tx3) Positive Lead 4 / +

B-2

TEMTADS MP 2x2 Cart Bulkhead and Internal Connectors

Table B-3 – Tx1 Tyco 206037-1 and Tx2 206036-1 Pin Out

206037-1 Socket contacts

Function Tx1 20-16 Pin

7 Sensor 1 (Tx0) Positive Lead D 11 Sensor 1 (Tx0) Negative Lead C 8 Sensor 2 (Tx1) Positive Lead P 12 Sensor 2 (Tx1) Negative Lead N 9 Sensor 3 (Tx2) Positive Lead R 13 Sensor 3 (Tx2) Negative Lead S 10 Sensor 4 (Tx3) Positive Lead H 14 Sensor 4 (Tx3) Negative Lead J

Table B-4 – Tx2 Molex 19-09-1029 Receptacle Pin Out (socket contacts):

19-09-1029 Function 1 (D-Shaped) Sensor Negative Lead

2 Sensor Positive Lead

Table B-5 – Rx1 Tyco 206305-1 and Rx2 206306-1 Pin Out

206305-1 Pin Contacts Function Wire Color Sensor #1 Sensor #2 Sensor #3 Sensor #4

B+ (Vcc) Positive Lead White 1 10 19 28 RX-axis Positive Lead Red 2 11 20 29 RX-axis Negative Lead Black (Red) 3 12 21 30 RZ-axis Positive Lead Blue 4 13 22 31 RZ-axis Negative Lead Black (Blue) 5 14 23 32 RY-axis Positive Lead Green 6 15 24 33 RY-axis Negative Lead Black (Green) 7 16 25 34 B- (Vdd) Negative Lead Black (White) 8 17 26 35 Ground (Vcc, Vdd, Common) Shield 9 18 27 36

Table B-6 – Rx2 Switchcraft / Conxall 3280-9sg-524 and Sensor Switchcraft / Conxall 4282-9PG-300 Pin Out

Function Wire Color 3280-9sg-524 socket contact

B+ (Vcc) Positive Lead White 1 RX-axis Positive Lead Red 2 RX-axis Negative Lead Black (Red) 3 RZ-axis Positive Lead Blue 4 RZ-axis Negative Lead Black (Blue) 5 RY-axis Positive Lead Green 6 RY-axis Negative Lead Black (Green) 7 B- (Vdd) Negative Lead Black (White) 9 Ground (Vcc, Vdd, Common) Shield 8

B-3

B-4

APPENDIX C. DATA FORMATS

C.1 TEM DATA FILE (*.TEM)

These data files are a binary format generated by a custom .NET serialization routine. They are converted to an ASCII, comma-delimited format in batches as required. Each file contains 4 data points, corresponding to each transmitter (Tx) cycle. Each data point contains the Tx transient and the corresponding 12 receiver (Rx) transients as a function of time. A pair of header lines is also provided for, one overall file header and one header per data point with the data acquisition parameters. A partial example is provided below.

Line 1 - File Header

TargetID,Bkgnd,Date,CPUms,GPSUTC,Lat,Lon,HAE,GPSFixQ,UTM_Zone,UTM_E,UTM_N,Elev,Heading,Pitch,Roll,Delt,BlockT,nRepeats,DtyCyc,nStk,AcqMode,GateWid,GateHOff,TxSeq,GateT,TxI_Z,Rx1Z_TxZ,Rx1Y_TxZ,Rx1X_TxZ,Rx2Z_TxZ,Rx2Y_TxZ,Rx2X_TxZ,Rx3Z_TxZ,Rx3Y_TxZ,Rx3X_TxZ,Rx4Z_TxZ,Rx4Y_TxZ,Rx4X_TxZ Line 2 - Data Point Header

4,0,5/28/2013,36985640.625,134934.30,38.409854552,-77.10894215,-33.570,4,18,315866.183,4253396.760,,253.956,3.98442,-2.81274,2E-06,0.9,9,0.5,18,2,0.05,5E-05,1 4 - Target ID 0 - Background file Boolean (1 = background) 5/28/2013 - Collection date 36985640.625 - Start time in ms on CPU clock 134934.30 - UTC time of data collection 38.409854552 - GPS Latitude (decimal deg.) -77.10894215 - GPS Longitude (decimal deg.) -33.570 - Height-above-ellipsoid (m) 4 - GPS Fix Quality 18 - UTM Zone 315866.183 - UTM Easting (m) 4253396.760 - UTM Northing (m) - GPS Elevation (m) – intentionally left blank 253.956 - IMU Yaw (deg, magnetic North referenced) 3.98442 - IMU Pitch ,-2.81274 - IMU Roll 2E-06 - Time step for transients (seconds) 0.9 - Base period length (seconds) 9 - Number of Tx cycles in a base period 0.5 - Duty cycle 18 - Number of base periods averaged (or stacked) 2 - Data Acquisition Mode (Decimated Decays) 0.05 - Gate width as fraction of its own time 5E-05 - Hold-off time (seconds) for first data point 1 - Tx coil ID number

C-1

Line 3 - First Data Line in First Data Point

,,,,,,,,,,,,,,,,,,,,,,,,,2.5E-05,0.491852843863786,-0.0019447468039619,-0.00167008188106537,0.00125536061090642,0.000316940817640296,0.000320902009700342,-0.000864236384734167,0.00112260623919521,-0.000175718325757418,0.000508878029254883,0.000640205921826291,0.00102392797989884,-0.000598618916918521 C.2 LOCATION AND ORIENTATION DATA FILE (*.GPS)

,Latitude/Easting/Pitch,Longitude/Northing/Roll,HAE/Zone/Yaw,Samples/UTC,FQ_0,FQ_1,FQ_2,FQ_3,FQ_4,FQ_5 GPS,38.409854552,-77.10894215,-33.570,20,0,0,0,0,20,0 UTM,315866.183,4253396.760,18,134934.30 IMU,3.98442,-2.81274,253.956,18 These data files are ASCII format, comma-delimited files. A header line is provided.

Line 1 – Header information

Line 2 – Raw GPS data

GPS - Data Type Identifier 38.409854552 - Latitude (decimal deg) -77.10894215 - Longitude (decimal deg) -33.570 - Height-above-ellipsoid (m) 20 - Number of samples received 0 - Number of samples with FQ 0 0 - Number of samples with FQ 1 0 - Number of samples with FQ 2 0 - Number of samples with FQ 3 20 - Number of samples with FQ 4 0 - Number of samples with FQ 5 Line 3 – Computer Location data

UTM - Data Type Identifier 315866.183 - UTM Easting (m) 4253396.760 - UTM Northing (m) 18 - UTM Zone 134934.30 - UTC Time Line 4 – IMU Data

IMU - Data Type Identifier 3.98442 - IMU Pitch (deg) -2.81274 - IMU Roll (deg) 253.956 - IMU Yaw (deg, magnetic North referenced) 18 - Number of samples

C-2

C.3 FIELD NOTES FILE (*.TXT)

Cart Rolled: False Interference with Measurement: False Recentered Array: False Data Issues: True Can't Center on Target: False 4-inch Aluminum sphere These data files are ASCII format, comma-delimited files. No header line is provided. The standard button captions are defined in the file “TEM_DataLogger_Notes.ini”

Lines 1 (- 6) – Standardized button information, if defined

Final Line – Comments, if any

C-3

APPENDIX D. SOFTWARE CONFIGURATION DETAILS

D.1 TEM_DATALOGGER WINDOWS REGISTRY SETTINGS

The contents of the TEMDataLogger Windows registry keys for use with the MP System is given below.

Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger] [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\Communications] "Wireless Enable"="True" "My IP Address"="192.168.1.202" "My Input IP Port"="11000" "Remote IP Address"="192.168.1.210" "My Transmit IP Port"="11001" "Serial Enable"="False" [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\Data Collection] "Sensor Mode"="2x2" "nStacks"="3" "nRepeats"="9" "StackPeriod"="0.9" "AcqMode"="Decimated" "GateToDisplay"="18" "MinTxCurrent"="5.5" "Sample Order"="0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35" "GateWidth"="0.05" "Sensor Height"="0.15" "FirstReliableGate"="18" "UnacceptableTxCurrent"="1.0" "Gate HoldOff"="5E-05" "FirstReferenceGate"="20" "LastReferenceGate"="60" "ReferenceThreshold"="0.25" “FirstReliableGate25” = “18” “FirstReferenceGate25” = “20” “LastReferenceGate25” = “60” “FirstReliableGate3” = “4” “FirstReferenceGate3” = “5” “LastReferenceGate3” = “11” [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\Data Files] "DefaultPath"="C:\\Documents and Settings\\Operator\\My Documents\\TEM Data" [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\Location And Orientation] "Expect Location"="True" "Location Port"="COM1" "Orientation Settings"="115200,8,N,1" "Location Settings"="115200,8,N,1" "Expect Orientation"="True" "Orientation Port"="COM2" [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\PlotAndTransmit] "SubtractNull"="True" "WaveformToPlot"="Full" "WaveformToTransmit"="Full" "SparsingFactor"="4" "SensorUp"="True" [HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\Run Options] "TestMode"="False"

D-1

[HKEY_CURRENT_USER\Software\VB and VBA Program Settings\TEM_Datalogger\SiteID] "Site"="a" "SubSite"="b"

D.2 TEM DATALOGGER NOTES CONFIGURATION FILE

The contents of the notes configuration file, TEM_DataLogger_Notes.ini, for use with the MP System and TEM_DataLogger v5.6.0 is given below.

TEM_DataLogger Notes Template - Enter up to six button captions Cart Rolled Interference with Measurement Recentered Array Data Issues Can't Center on Target

D.3 TEM DATALOGGER SENSOR REFERENCE FILE

The contents of the Sensor Reference files, for use with the MP System and TEM_DataLogger v5.6.0 are of the format given below. Only the header lines are reproduced for brevity.

NumGates 122 Tx,GateT,Rx1Z_TxZ,Rx1Y_TxZ,Rx1X_TxZ,Rx2Z_TxZ,Rx2Y_TxZ,Rx2X_TxZ,Rx3Z_TxZ,Rx3Y_TxZ,Rx3X_TxZ,Rx4Z_TxZ,Rx4Y_TxZ,Rx4X_TxZ …

D.4 EM3D 2013 CONFIGURATION FILE

The contents of the current configuration file, em3dAcquire.LOGGEROVER.v2.ini, for use with the MP System and EM3D 2013 is given below.

[SYSTEM] SystemID = LOGGEROVER; GPSAntennaCoordinate = 0,0,0 CartHeightAboveGround = 0.04 CartHeading = 0 DAQClock = DAQInternal SignalTiming = Standard60Hz; Standard50Hz; ModuleType = PXI6123; PXI6143; DeltaT = 0.000002 NModules = 2 Module00 = Dev1 Module01 = Dev2 NComponentsPerRxSensor = 3 [RXANTENNAS] ;ChID = X,Y,Z Rx01 = -0.2,0.2,0.0 Rx02 = 0.2,0.2,0.0 Rx03 = 0.2,-0.2,0.0 Rx04 = -0.2,-0.2,0.0 [TXANTENNAS] ;Tx04Z = -0.2,-0.2,0.0,25,0.35,0.35,0.08 ;ChID = X,Y,Z,NTurns,XDim,YDim,ZDim,AxisHdg,AxisPitch,Type Tx01Z = -0.2,0.2,0.0,25,0.35,0.35,0.08,0,90,Rectangular Tx02Z = 0.2,0.2,0.0,25,0.35,0.35,0.08,0,90,Rectangular Tx03Z = 0.2,-0.2,0.0,25,0.35,0.35,0.08,0,90,Rectangular Tx04Z = -0.2,-0.2,0.0,25,0.35,0.35,0.08,0,90,Rectangular

D-2

[RXCHANNELS] ;ChID = Mod,Chan,StkOnTime,StkPN,Gain,ADCGain Rx01X = 0, 1, FALSE, PN, 1000, 1, 1 Rx01Z = 0, 2, FALSE, PN, 1000, 1, 1 Rx01Y = 0, 3, FALSE, PN, -1000, 1, 1 Rx02X = 0, 4, FALSE, PN, 1000, 1, 1 Rx02Z = 0, 5, FALSE, PN, 1000, 1, 1 Rx02Y = 0, 6, FALSE, PN, -1000, 1, 1 Rx03X = 1, 1, FALSE, PN, 1000, 1, 1 Rx03Z = 1, 2, FALSE, PN, 1000, 1, 1 Rx03Y = 1, 3, FALSE, PN, -1000, 1, 1 Rx04X = 1, 4, FALSE, PN, 1000, 1, 1 Rx04Z = 1, 5, FALSE, PN, 1000, 1, 1 Rx04Y = 1, 6, FALSE, PN, -1000, 1, 1 [TXCHANNELS] Tx01Z = 0, 0, TRUE, PN, -0.1, 1, 1 Tx02Z = 0, 0, TRUE, PN, -0.1, 1, 1 Tx03Z = 0, 0, TRUE, PN, -0.1, 1, 1

D-3