trimble access land seismic guide

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DEMONSTRATION GUIDE

VERSION 1.0

April 2013

TRIMBLE ACCESS LAND SEISMIC APPLICATION

The Land Seismic Application for Trimble Access offers unique capabilities intended for the Land Seismic stakeout professional. The workflow in this application allows faster and more accurate operations.

This guide provides an introduction to land seismic surveying, an overview of the major features of the land seismic application, and recommendations on how to best demonstrate this solution. It is assumed that the reader already has a working knowledge of Trimble Access and the General Survey application.

The contents of this guide are arranged for a complete first reading and then to be used as a reference. There are several appendices with supporting information and a glossary of terms. This information is intended for sales and technical staff, not for end users. There are other resources specifically structured for our customers that do not explain all of the industry details.


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Contents General Capabilities ....................................................................................................................................................... 5

Introduction to Land Seismic Stakeout .......................................................................................................................... 5

Trimble Access Land Seismic Application Operations ................................................................................................. 11

Creating Jobs ........................................................................................................................................................... 11

File Types ................................................................................................................................................................. 12

Job Options .............................................................................................................................................................. 13

Exclusion Zones ....................................................................................................................................................... 13

Smart Point Incrementing ....................................................................................................................................... 14

Reference Method .................................................................................................................................................. 14

Layout tolerance ..................................................................................................................................................... 15

Point Names and Codes .......................................................................................................................................... 15

Display orientation .................................................................................................................................................. 16

Grid Definition File Line Display .............................................................................................................................. 16

Other Options .......................................................................................................................................................... 17

Stakeout Operations ............................................................................................................................................... 18

2‐D Stakeout ............................................................................................................................................................ 18

Exclusion Zones ....................................................................................................................................................... 21

Template Offsets ..................................................................................................................................................... 21

Creating New Zones in the Field ............................................................................................................................. 23

Using General Survey Continuous Topo with Land Seismic .................................................................................... 25

Keying in Grid Points ............................................................................................................................................... 28

Taking Photos .......................................................................................................................................................... 29

Measure Codes ........................................................................................................................................................ 30

Viewing and Exporting Reports ............................................................................................................................... 32

Sample Demonstration Activity ................................................................................................................................... 33

Required Materials .................................................................................................................................................. 33

Preliminary Operations ........................................................................................................................................... 33

Indoor Demonstration ............................................................................................................................................. 33

Outdoor Demonstration .......................................................................................................................................... 33

Demonstration Workflow ....................................................................................................................................... 34

Appendix A – Unique File Types Used by the Land Seismic Application ..................................................................... 36

Appendix B – Formatting CSV Files for the Land Seismic Application ......................................................................... 39

Appendix C – Trimble Access Land Seismic Application Techsheet ............................................................................. 43

Appendix D – Trimble Access Project Helper Application ........................................................................................... 45

Appendix E – Coordinate Conversions......................................................................................................................... 47

Glossary of Terms ........................................................................................................................................................ 50


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General Capabilities The Trimble Access Land Seismic Application offers a specialized workflow for seismic stakeout operations using either GNSS or conventional instruments. This application is different from other stakeout utilities in that it uses the terminology of seismic operators and provides unique navigation cues for this profession. The application is fully compatible with the GPSeismic software suite. Land Seismic provides exclusion zone awareness to operators in the field. With this application, it is possible to undertake accurate, systematic offsetting in the field without performing calculations. It is also easy to move between General Survey and the Land Seismic application whenever standard survey operations are encountered.

Introduction to Land Seismic Stakeout The land surveyor’s activities only represent a small portion of the overall labor undertaken in the course of a seismic survey. However, the land surveyor’s contribution is very important to achieve high quality results in the assessment of what lies below the Earth’s surface.

Trimble’s solutions for land seismic include GPSeismic software for office use. This software suite bridges the disciplines of Geophysics and Geodetics. GPSeismic is used to create the ideal “preplot” to achieve the geophysicist’s goals for a seismic survey. It is also used to alter this preplot to reflect features and hazards located during preliminary surveys. These final preplot locations are loaded into the Trimble Access Land Seismic application for field stakeout operations. The Land Seismic application provides navigation guidance in industry‐standard terms and supports proper offsetting without any calculations. The final as‐staked locations are easily transferred from Trimble Access back into GPSeismic to create the final “postplots” for a seismic survey job. The following section explains the overall land seismic survey operation and the aspects that rely on Trimble survey solutions.

Figure 1 ‐ Land Survey Activities Supporting a Seismic Survey


Seismic surveys seek to discover the structure of features below the Earth’s surface. The most common motivation for undertaking seismic surveys is to locate petroleum deposits. In the course of a seismic survey, energy is injected into the ground as vibrations and the reflected signals are detected and recorded. From this, the shape and location of underground formations can be determined.

Figure 2 - Reflected Signals are Detected to Map Underground Features

The injected energy is provided by energy sources, or simply “sources”. Sources are normally either explosives detonated in drilled holes or hydraulically shaken pads on vehicles. These vehicles are usually vibroseis trucks or vibroseis buggies. Modern vibroseis vehicles transmit energy into the earth very efficiently and forcefully at specific frequencies and can even sweep through a range of frequencies while shaking.

Figure 3 ‐ Vibroseis Truck and Drill Truck

To make use of the injected energy, the reflected signals must be detected. This is accomplished with receivers also known as geophones. Geophones are placed in firm contact with the earth and are connected to each other and a recording system using cables, or sometimes, radio links.


Figure 4 - Sample Geophone, Pressed Into Ground, Interconnecting Cable in Staging Yard

Large arrays of geophones are connected to recording trucks. Seismic data recording operations are controlled from the recording truck. This is also where the data is centrally collected.

Figure 5 - Recording Trucks Facilitate Seismic Data Collection

The geometric arrangement of sources and receivers determines the resolution of the seismic survey and the depth of data collection.

Figure 6 ‐ Element Arrangement Determines Qualities of Seismic Survey

Geophysicists design the layout of a seismic survey to suit the qualities of a prospect. The size of the area to be studied, the properties of the underlying materials, the technology to be applied, and the available funding to collect the information all affect the design of the seismic layout. In 3‐D seismic surveys, geophysicists divide the prospect into an ideal grid. This process is called “Binning” and each unique area within the grid is called a “bin”. Within this ideal arrangement, sources and receivers are intended to be placed in the center of bins. These bin center locations are at the intersections of two perpendicular sets of lines. The line sets are call “Track lines” and “Bin Lines”.


Figure 7 ‐ Seismic Binning Scheme

A unique, numeric identifier for each bin is created by combining the track line number with the bin line number. The line numbers are commonly either 3 or 4 digits, making the bin numbers commonly either 6 or 8 digits. These bin numbers are usually the surveyed point numbers. Figure 7 below shows a survey stake at the center of a bin at the intersection of track line 5208 and bin line number 1832. Surveyors will locate the proposed locations of all sources and receivers in a prospect and mark these locations with stakes or pin flags. The Trimble Access Land Seismic application is used for these stakeout operations.

Figure 8 ‐ Seismic Survey Stake at Bin Center


Before the ideal layout of the seismic survey can be undertaken, many additional details must be collected. Prospects are usually mapped to initiate permitting processes. It is common to collect topographic information for the entire prospect area either with Lidar or other forms of remote sensing.

Survey teams will undertake hazard, access, and specific topographic surveys. Hazards are items that cannot be occupied with seismic energy sources, or potentially, cannot be occupied by crew members due to permitting restrictions. Examples of hazards are waterways, wells, pipelines, utility lines, building foundations, storage tanks and cultural sites. You can imagine that it is not desirable to detonate explosive charges in the ground in close proximity to an active petroleum pipeline. A hazard survey captures the locations and extents of all hazards on the prospect. Access surveys locate roads, fence gates, and best paths to plan crew travel logistics during the seismic survey. Topographic surveys are used to plan crew travel logistics and also to determine how a prospect will be traveled upon. Severe slopes may prevent travel by certain types of vehicles.

All of this initial survey information is used to alter the design of the seismic survey layout. The ideal design created by the geophysicists will be altered to address the located hazards and extreme topography. GPSeismic software is used to create the ideal layout and to modify that layout based on the realities determined during the preliminary surveys. If for instance, the hazard survey locates an irrigation pipe in the prospect, GPSeismic will be used to create an “Exclusion Zone” around that pipe so no energy is injected into the ground within a prescribed distance. GPSeismic will also relocate the energy sources and receivers to avoid placement within the exclusion zone while still providing the best possible seismic data.

The plan for seismic element placement created by GPSeismic is called a preplot. The preplot contains all of the proposed locations of sources and receivers. The preplot information is used to create the target positions for field stakeout.

Figure 9 ‐ Ideal Preplot and Revised Version Based on Preliminary Surveys


Figure 10 ‐ Preplot Created in GPSeismic with Exclusion Zones Around Wells in Red

Equipped with the preplot points, surveyors will place evidence in the field to mark the seismic element locations. The evidence commonly takes the form of stakes, pin flags, or spray painted marks on the ground. There are two tolerances in this stakeout process. There is the layout tolerance which determines how precisely the surveyor should try to place the evidence on the target location. This is often on the scale of one meter. There is also the accuracy tolerance. This is the precision within which the final location of the evidence must be known.

A surveyor in the field will approach a target location to within the stakeout tolerance. They will then place their evidence on the ground. The final step at this location is to measure the location of the evidence. This measurement must be within the accuracy tolerance. This location will be used to process the actual seismic data. This final position for the seismic element will go into a record called a postplot. This postplot contains the final survey data used to process the seismic survey and represents the end of the land surveyor’s role in the larger seismic survey process.

It is common for unmapped hazards to be encountered during seismic stakeout and these require that the surveyor undertake offsetting in the field. Each seismic survey will have specifications or rules for offsetting the staked point when the preplot location cannot be occupied. If a large tree is located close to a proposed vibroseis truck location, it may be desirable to offset the location of this point so the energy source location can be occupied without cutting down the tree. This tree was not noted during the initial survey because it is not a hazard, but nevertheless the desire is to preserve it. In this case, the field surveyor will relocate the staked point, following job‐specific rules, to an offset location which provides good seismic data and does not require clearing the tree. This new point will be reflected in the postplot. This is just one example of a cause for field offsetting. There are many others and the postplot is commonly quite different from the preplot.

Following the survey stakeout process, layout crews will place geophones or energy sources at each marked location. After layout, the actual seismic survey will be undertaken. If trucks are used as energy sources, operators will drive over the evidence left by the survey crew. The layout and vibroseis crews will strive to place components exactly on the marked locations so the postplot positions represent real world conditions.


The major involvement of land surveyors ends once the evidence has been placed in the ground. Sometimes surveyors will be asked to verify the proper placement of vibroseis trucks or to replant evidence during the actual seismic survey. In general though, they will not undertake any more survey work in an area of the prospect that has been staked.

During the actual seismic survey, energy sources will be activated‐ vibroseis trucks will shake or explosive charges will be detonated. The received signals from the geophones will be collected in a recording truck. A comprehensive record of the energy source characteristics and timing will be collected at the same time. Later, these records along with the postplot element coordinates will be used to complete the seismic analysis of the prospect.

There are many educational videos on the topic of seismic surveying available on the Internet. For more information, search for videos using the string “Seismic Survey” or “3D Seismic”. There is a Trimble video on the overall land seismic workflow using GPSeismic and the Land Seismic application. Search videos on the Internet for “Trimble Land Seismic Survey Workflow” to find this item.

Trimble Access Land Seismic Application Operations

Creating Jobs Within the ‘Job’ section of the Land Seismic application, there’s an option to create a new job. A job is a file which stores all settings and surveyed information. Users will typically create one job per day to hold all the surveyed points acquired on that day. A common method in creating jobs is to use the surveyor’s initials along with the date.

Figure 11 - Sample Job Properties

Be sure to specify the appropriate template for the job. For associating preplots and control points with the new job, we recommend the use of ‘Linked files’ in the form of .csv with a field order of station, easting, northing, height, descriptor (the height and descriptor are optional, see Appendix B for detailed formatting information about these files). Note that Trimble Access is expecting the coordinates in a .csv file to be local with the height as orthometric. Although the GPSeismic QuikLoad application has the option to create .job files for both control and preplot points with coordinates in WGS84, the use of .csv files is both faster and works with all versions


of General Survey, whereas .job files must be explicitly created for the specific version of General Survey which is in your controller. There are numerous places in GPSeismic to create .csv files including QuikMap, QuikLoad, QuikView and GPSQL. You can link multiple .csv files with your new job and points from any of these files can be used for stakeout and to set your base station.

Figure 12 - Linked Files Selection

Once the points for use as control have been loaded in your job, we highly recommend that you view at least one point in the ‘Point manager’ in both Grid and WGS84 as toggled via the ‘Display’ button. It is the WGS84 coordinates which will be used by the system so it is critical that the WGS84 latitude, longitude and height accurately reflect your control.

Figure 13 - Verifying at Least One Point in Point Manager

File Types The four main GPSeismic file types that are used in Trimble Access are:

Grid Definition File (.GDF) Crooked Line File (.CRK) Exclusion Zone File (.XZO) Template File (.TPL)

Appendix A describes each of these file types and their contents in more detail.


Job Options There are several user-selected options in the Job menu. While the selected elements may vary from job to job, it is important to understand the relevance of each option.

Exclusion Zones In the Jobs page, there is a button named ‘Exclusion zone’. This page will allow the user to specify a file containing monitored exclusion zones, the color to render the zones, and the radius and color of point buffer circles.

Figure 14 - Exclusion Zone Selections

Both GPSeismic .xzo files as well as ESRI area shape files can be selected for use as exclusion zones. Note that if you choose a shape file, you will not be able to append any field created zones to it. Point buffer circles are circular map annotations which surround each point to allow a visual proximity check. Examples of each are shown here:

Figure 15 - Sample Exclusion Zones and Point Buffer Circles


Smart Point Incrementing To automatically sequence from the current point to the next logical point to survey, the system allows for positive and negative increments which can also be fractional (in case of 2‐D half‐stations). When combined with the option to ‘Automatically search for next or previous point’, sequences such as 101, 101.5, 102, 103, 103.5 (half‐stations at odd points only) can be achieved with no further prompting.

Reference Method Seismic stakeout requires the resolution of offsets (where you are versus where you need to go) in terms of inline and crossline. The Trimble Access Land Seismic application allows for five such methods to determine the inline azimuth as shown in Figure 21.

Figure 16 - Reference Methods Available in Land Seismic application

When staking a 3‐D survey where either the source or receiver geometry adheres to a GPSeismic grid definition file, a GPSeismic .gdf file can be selected. When shooting a 2‐D line with bends or without, a GPSeismic crooked line file, .crk, can be used which will defined the inline azimuth as a function of point number. Note that point names can have alpha characters and these will be correctly handled.

Figure 17 - Stake Out Point Display


Layout tolerance There are generally two survey tolerances in use in land seismic projects. These are known as the layout tolerance and the accuracy tolerance. The former is defined as how close the survey evidence (pin flag, stake, paint dot, etc.) must be to the theoretical preplot location. The accuracy tolerance is defined as the accuracy of the coordinates which are assigned to the survey evidence. A reasonable layout tolerance, say one meter, can significantly improve survey production ‐ have you ever seen a pack operator move the pole ten or more times to set the pin flag with 5cm of the preplot? The Trimble Access Land Seismic application allows the user to define the layout tolerance. When this tolerance is achieved, the offset characters in the Stake out display will turn green. This is shown for the Current inline and Current crossline values in Figure 12.

Figure 18 - Layout Tolerance Field in Options Menu

Point Names and Codes The Land Seismic application provides a number of options when assigning names and codes to surveyed points. Typically, users will want the name of the surveyed point to be the name used on the preplot. This is achieved by setting the ‘As‐staked’ name to ‘Design name’. Each point is also assigned an optional code which can be name of the preplot, code of the preplot (if codes were part of your linked .csv file), the code used for the previously surveyed point, or, when using a grid definition file, it is possible to ‘bin’ the point by setting the code to the computed track and bin at the surveyed location.

Figure 19 - Point Naming and Coding Options


Display orientation The stakeout display consists of multiple panels. The left‐most portion displays a large arrow which points to the target with respect to whatever is selected as ‘up’ on the display. The options are ‘Direction of travel’, ‘Reference azimuth’, and ‘North’. When using ‘Direction of travel’, you will always be heading ‘up’ and the arrow will guide you to the point based upon the direction you’re now heading. When ‘Reference azimuth’ is selected, up on the display is fixed to the inline azimuth regardless of whether you’re heading up or down a line. In all cases, the arrow always points to the target.

Figure 20 - Sample Stakeout Display Using Reference Azimuth

Grid Definition File Line Display

When using a GDF file as the reference method, the user may choose whether to display bin borders (cell) in the map view. To show the bins, tap and hold on the map view. The display options menu will appear as shown below. Select Show grid definition file lines. The display options menu will disappear and the GDF lines will display on the map.

Figure 21 - Tap and Hold on Map View to Show Grid Definition File Lines

To hide the GDF lines, tap and hold on the map view and select Hide grid definition file lines. The display options menu will disappear and the bin borders will no longer be displayed.

Figure 22 - Hiding GDF Lines


Other Options The final page of the Options section contains the following choices:

Display perpendicular reference azimuth: On the stakeout display, when you are with a few meters of the point, a line along the reference azimuth will be drawn through the target. If you would like to rotate this line 90 degrees, check this box. This feature can facilitate visually setting offsets pure crossline. In this case, you would stake the offset so that you stay on the rotated line.

Compass: The TSC3 has a built in compass which can be used to set the orientation of the stakeout display. As twisting of the TSC3 will result in the display being rotated, it is generally recommended that this option be unchecked.

Display cut/fill: When surveying checkpoints, it is useful to see your vertical ties directly from the stakeout display (note they are always available via the map display). Checking this box will display your cut/fill on the stakeout display.

Automatically search for next or previous point: In cases where a single increment will not match your preplots, i.e., half‐stations at odd points only, checking this box will automatically sequence to the next logical point without issuing a warning.

Warn if point has already been staked: When checked, if you target a preplot which has already been surveyed, a warning will be issued. This warning can be cancelled and you can proceed to survey the point again.

Figure 23 - Additional Options Within Land Seismic


Stakeout Operations This section describes how to undertake stakeout operations with the Land Seismic application.

2-D Stakeout We’ll begin with a 2‐D example using a crooked line file for the reference azimuth. We can choose a point to target in a number of ways – Either key it in, choose ‘Closest’, or select it from the map display. Once selected, the center panel provides offsets to the target in terms of inline and crossline. The large arrow points to the target. The right‐most panel provides information on the controller and receiver battery levels, number of satellites in use, radio status, and the current antenna height entry. These icons also serves as buttons which, when tapped, present more detailed information and settings.

Figure 24 - Sample 2-D Stakeout Display

Tapping on the ‘Map’ window will present the map display as shown below.

Figure 25 - Sample 2-D Map Display


The current rover position is always displayed as a green cross. Full zoom and pan capabilities are available as well as control over point labels, map layers to present (.jpg, .dxf, and .shp files are supported) and many other customizations. Point buffer circles as well as grid definition file lines (when applicable) are available via tapping and holding to present a popup menu:

Figure 26 - Sample Map View with Additional Details

When the rover is within the layout tolerance of the target, the offsets turn green as shown below:

Figure 27 - 2-D Stakeout Screen Within Layout Tolerance

Pressing ‘Measure’ will display a screen where you can confirm the point name, code, and antenna height. The ‘Topo point’ method is appropriate for land seismic stakeout.


Figure 28 - Pressing Measure Reveals Point Details for Verification

Option for the ‘Topo point’ method can be accessed via the ‘Options’ button.

Figure 29 - Topo Point Options

Once these values are set, they are persistent. These settings can also be configured via ‘Survey Styles’. Pressing ‘Measure’ from the ‘Stakeout point’ screen will begin the recording process as determined by the topo point settings. Once the point is stored, the system automatically sequences to the next point to survey. As the stakeout display constantly displays offsets in terms of inline and crossline, setting offsets in any combination of inline or crossline distances is easily accomplished.


Exclusion Zones When exclusion zones are active, entering a zone will immediately cause the navigation values to display in red.

Figure 30 - Sample 2-D Stakeout Display When Operating in an Exclusion Zone

The name of the zone which you entered will be displayed in red at the top‐center of the stakeout display and the offsets will also be displayed in red. As some exclusion zones apply to sources only, and not to receivers, seeing the name allows the operator to determine if the warning can be safely ignored. Switching to the map display also shows your position with respect to the exclusions zone. From the map, tapping inside an exclusion zone will display the zone name at the bottom panel.

Figure 31 - Map View of an Exclusion Zone

Template Offsets When the point you are targeting falls inside an exclusion zone, the template offset feature is an excellent tool to determine the optimal location to offset the point. When a template offset file has been selected, tapping the ‘Options’ button from the stakeout display will present a list of offsets in terms of inline and crossline from the target where an asterisk indicates if that location is inside an exclusion zone.


Figure 32 - Sample Offsets Template Options Screen

Pressing the ‘Best OS’ button at the bottom will select the highest priority (lowest numbered) offset which falls outside the exclusion zone (offset number 13 in this example).

Figure 33 - Selected Template File Offset

Pressing ‘Accept’ will take you back to the Stakeout display where a new target location has been created at the offset location, and has been given a temporary name of the original preplot name followed by a colon then the template offset selection. In Figure 27 this is “27:TPL13”.

Figure 34 - Sample Stakeout Display with Template Offset Targeted

Navigate to within the layout tolerance, press ‘Measure’, and the original preplot name will be assigned to the surveyed point.


Figure 35 - Measured Point Name Does Not Include Template Offset Description

Creating New Zones in the Field When using a GPSeismic exclusion zone file (.xzo), the Land Seismic application allows you to create new zones from surveyed or preplot points. Say, for example, the surveyor encounters a wellhead in the field that was not surveyed in the planning stage of the project. Simply measure this point by occupying the location and pressing the ‘Measure’ button from either the Stakeout or Map display. Assign a name to the point, say, wellhead, and record it.

Figure 36 - Measuring a Point to Create an Exclusion Zone in the Field

This location is now shown on the map display.

Figure 37 - Newly Measured Point in the Map Display

If the project specifications require that all source locations be at least 10 meters from wellheads, you can create this new exclusion zone by tapping and holding on the Wellhead point to bring up a menu:


Figure 38 - Tap and Hold on Point to Bring Up "Add exclusion zone" menu item

Choosing the ‘Add exclusion zone’ item will take you to a page where you can define the parameters of this new exclusion zone.

Figure 39 - Add Exclusion Zone Display

Set the criteria and press ‘Add’. The new zone is appended to the current .xzo file and active in the Land Seismic module.

Figure 40 - Point With Radius Style Exclusion Zone in the Map View


Note that field create zones can be deleted by taping and holding inside the zone and choosing ‘Delete Exclusion zone’.

Figure 41 - Field Created Exclusion Zones Can Also Be Deleted in the Field

Only zones created in the field can be deleted. Users cannot delete exclusion zones which were created in the office. As in GPSeismic, field created zones can be in the form of circles, sequential rectangles and polygons. For circles, only one point is needed. Rectangles require a minimum of two points while polygons require a minimum of three points.

Using General Survey Continuous Topo with Land Seismic As another example, say you encountered a structure in the field which was not surveyed previously. The General Survey module provides a means to perform a continuous topo survey where points can be automatically recorded based upon elapsed time, distance travelled, or both. General Survey can be launched while Land Seismic is running and each module can run simultaneously. Tapping the Trimble icon in the top‐left of any window will bring up a list of running modules.

Figure 42 - Tap the Trimble Logo to Access all Operating Trimble Access Applications


Choose ‘Trimble Access’, ‘General Survey’, ‘Measure’, then ‘Continuous topo’. Specify the recording parameters, and press ‘Start’.

Figure 43 - Continuous Topo Menu

Walk the perimeter of the structure auto‐recording as you go and press ‘End’ when finished. Return to Land Seismic via the Trimble icon. When you return to the Map, your structure will be shown.

Figure 44 - Continuous Topo Points Displayed in Land Seismic Map View

To create a polygonal exclusion zone from these points, drag a rectangle around them all to select.

Figure 45 - Points Selected to Create a Polygon


To see your current selection, tap and hold on the map away from any points and choose # items (where # is the number of points selected).

Figure 46 - Review of Points Selected for a Polygon

Ensure that only the points for this new structure are selected. Press ‘Esc’, tap and hold on the map and choose ‘Add exclusion zone’. Select the ‘Polygon’ option for the zone type, enter a name for the zone, and an expansion distance for how far you must stay away from the zone (say, 2m).

Figure 47 - Adding a Polygon Exclusion Zone

Pressing ‘Add’ will create and append this zone to your .xzo file.

Figure 48 - Polygonal Exclusion Zone Expanded 2.0m Beyond Perimeter of a Surveyed Structure


Entering this zone from the Stakeout display will result in the offsets turning red and the zone name being displayed above the arrow.

Figure 49 - Stakeout Display with Rover Operating In Field-Created Exclusion Zone

Keying in Grid Points In may be desirable to create a design target points in the field at the center of bins that were not intended to be staked in the preplots. This capability uses a grid definition file to create a new design point at a particular bin’s center. To do this, select the Key in menu item.

Figure 50 - Key In Menu Item

Next, select the Seismic Grid Points item.

Figure 51 ‐ Seismic Grid Points Selection


In the next screen that appears, make sure that the desired GDF file is selected. Enter a point number made up of the track and bin ranges displayed at the bottom of the page. In the example below, the track number is 138 and the bin number is 543.

Figure 52 ‐ Creating Design Point

Once the valid point number is entered, the coordinate details for this location will be displayed. Press the Store button to make this new design point available for targeting. Figure 48 shows the example point displayed in the map view.

Figure 53 ‐ Sample Keyed In Grid Point in Map View

Taking Photos The Trimble TSC3 has an internal 5 MP digital camera. Photos can be taken at any time and one or more photos can be assigned as attributes to any surveyed point. This can be extremely useful for documenting field conditions and encountered hazards. On page 2 of the Job properties, there is an entry for ‘Media file’.


Figure 54 ‐ Job Properties Menu Affecting Collected Photos

If you plan on surveying the point first and then taking photos, choose ‘Previous point’ to have the photos assigned to the point you just surveyed. Photos are recorded as .jpg files and stored in the user folder along with the .job file. When this data is transferred to your office computer and processed with QuikView, these photos are stored as attributes in the project database and can be previewed via the right‐click and hold feature:

Figure 55 - Photo Attribute of Point Displayed in GPSeismic QuikView

Measure Codes To measure and code observations in one step, select the feature code you want to measure and store from a coding form containing nine buttons that you can define. You can define multiple groups or pages of codes, each consisting of up to nine codes. In the Measure codes form, if you activate the Code button, it affects the behavior of the nine configurable code buttons. When you then tap one of the configurable code buttons, the code on that button is added to the code field at the bottom of the Measure codes form. Typically, you can use the


Code button to combine codes from multiple code buttons where features combine, either from the current group, or a combination of groups. You can also use it to enter a new code. If a code has attributes, the attribute values appear at the bottom of the Measure codes form. You cannot directly edit these attribute values in the form. To change the attribute values, do one of the following:

Tap Attrib in the Measure codes form.

Tap Attrib in the Measure topo/Measure points form.

If Prompt for attributes is enabled, enter the attributes when prompted. o If you pre‐entered attributes using the Attrib softkey, you are not prompted for

attributes. To add a feature code group and assign codes to the buttons:

1. Select Measure / Measure codes and then tap Add group. 2. Enter a Group name and then tap OK. 3. To add a code to a button:

Tap and hold on the button. When the tooltip message appears, remove the stylus from the screen. In the dialog that appears, enter the code, or select a code from the feature code library.

Navigate to the button using the arrow keys, and then press the Space key, which emulates the “tap and hold” action.

If required, you can also enter additional descriptions. 4. To add another code, or remove a code from a button, repeat Step 3. 5. To add more groups of feature code buttons, tap Add group.

To navigate to a particular group, select it from the drop down list in the top left of the form. Alternatively, use A – Z to quickly switch to group pages 1 – 26. This method is not available if the Code button is enabled. New groups are added after the current group. To add a group to the end of existing groups, ensure you select the last group before selecting Add group.


Viewing and Exporting Reports

The Trimble Access Land Seismic application can easily provide stakeout activity reports for a job. To do this, select the Reports item from the Land Seismic main menu.

Figure 56 ‐ Reports Menu Selection

After pressing the Reports button, the list of available reports will be displayed.

Figure 57 - List of Available Reports

The selected report will be created and exported to the current user’s Export folder on the field controller. The report will also be displayed on the field controller screen in a browser window.


Sample Demonstration Activity It is highly recommended that all demonstrations begin with indoor simulations projected onto a large screen for easy viewing. This setting makes it easy to address a larger group and to answer questions. Following the indoor activity, the demonstration can move outdoors to highlight the performance of the GNSS receiver and to allow demonstration attendees to operate the system themselves.

Required Materials Demonstration Computer with: Trimble Access Emulator including Land Seismic Application Trimble Access Project Helper Large Viewing Screen Trimble GNSS rover complete with TSC3, and Trimble Access Land Seismic application (Bipod recommended) (More than one rover may be needed depending on group size) Source of RTK corrections (this may be an entire base station) Cones, chalk, or pin flags to mark locations in the demonstration area

Preliminary Operations

These items should be undertaken before arriving at the demonstration site. The staff providing the demonstration may choose to repeat some of these steps in front of the customer or discuss them with the customer. If this is the case, it is still necessary to perform all of these preliminary operations before traveling to the demonstration location.

1. Locate area to be used in demonstration. 2. Determine grid coordinate system to be used. 3. Determine grid coordinates of center of demonstration area. 4. Use Trimble Access Project Helper to generate demonstration files. See Appendix D for details. 5. Load demonstration files into a job in the Trimble Access Emulator 6. Load demonstration files onto the TSC3 that will be used in the field 7. Configure the TSC3 for the settings referred to above, i.e., coordinate system, linked files, layout

tolerance, exclusion zone file, template offset file…

Indoor Demonstration 1. Set up display that can be viewed by group and is driven by the demonstration computer 2. Launch Trimble Access Emulator and display on the viewing screen 3. Steer the TA Emulator to provide coordinates within the sample project area 4. Undertake the Demonstration Workflow procedure

Outdoor Demonstration 1. Set up the local RTK base station and make sure that it is communicating with the

demonstration rover(s).

2. Verify accurate RTK rover positioning.

3. Undertake the Demonstration Workflow procedure


Demonstration Workflow 1. Select the 2D csv file (do not select both the 3D and 2D files simultaneously as these require

different reference azimuth methods and may cause map clutter) for stakeout and the crooked line file for the reference azimuth method along with the applicable crk file.

2. Specify your point increment and layout tolerance.

3. Wander to a location within the job area and choose the nearest point to stakeout. Use the ‘Direction of travel’ for the display orientation and start moving toward the point.

4. Stakeout, mark, and survey the point. Be sure to select the ‘auto store’ option via the ‘Measure’ screen Options button. Be sure to discuss point coding during at least one collection sequence.

5. Sequence to the next point, stakeout, mark and measure. Highlight the inline and crossline offsets and how simple offsetting a point can be.

6. Swap over to the map display and discuss zooming, panning, the point symbols, labels, and turn on/off the point buffer circles. Also tap on exclusion zones to see the attributes.

7. Move inside an exclusion zone and notice the behavior on the stakeout display.

8. Via the map display, choose a point to stakeout which is inside an exclusion zone.

9. Manually offset this point outside the zone using the stakeout and/or map display. Notice how the point buffer circles can assist offsetting.

10. Choose another point to stakeout which is inside a zone.

11. This time use the template offset feature to offset the point. Mention the name of the target point with the :TPL# suffix, yet when Measure is pressed, the original point name is preserved.

12. Measure a feature outside any exclusion zone (a car, curb, tree, etc.). Use the map display to demonstrate selecting then creating a circular exclusion zone around this point.

13. Choose another feature and, with Land Seismic running, switch over to General Survey and start a Continuous Topo survey on distance, say 2m, and go around this feature.

14. End Continuous Topo, return to Land Seismic and go to the map display to select these new points (you may need to clear any previous selection) and create a polygonal exclusion zone (or polyline with buffers if not a closed figure) from this data.

15. Delete a user created exclusion zone and mention that only zones created on the controller can be deleted.

16. Go to Job Properties, deselect the 2D csv file and select the 3D file.

17. Change the point increment accordingly and choose ‘Grid definition’ for the reference method along with the applicable gdf file.

18. Choose the closest 3D point to stakeout and notice the ‘Current bin’ portion of the stakeout display.

19. Switch to the map display and turn on the ‘grid definition file lines’.

20. Stakeout a few 3D points and see that all options including template offsetting are available in this mode as well.

21. ‘Key in’ a new point within the grid that falls between track lines and stake this out.

22. After staking out a point, use the TSC3 to take a photo of the point. (Outdoor demonstration only)

23. Repeat the photo collection on a second point and discuss how to make the photo an attribute of the point. (Outdoor demonstration only)


24. Let customers undertake all of these operations themselves.(Outdoor demonstration only)

25. Answer questions and review features as requested by demonstration attendees.


Appendix A – Unique File Types Used by the Land Seismic Application

Grid Definition Files (.GDF) contain a number of numerical parameters which can be used

to compute grid coordinates given a station number, or compute a station number given grid coordinates.

Grid definition files can be used in GPSeismic for various purposes including re‐binning, a process whereby stations are renumbered to match their location. These files are used in Trimble Access Land Seismic to determine what bin the surveyor is in and provides offset values to the bin center.


Crooked Line Files (.CRK) contain station numbers and an associated azimuth for each of

those stations. These files are used in GPSeismic and Trimble Access Land Seismic in order to provide reference azimuths for computation of inline and crossline offset values for any station regardless of what segment of a crooked line it might fall on.

Exclusion Zone Files (.XZO) contain various polygonal zones which can represent exclusion areas for a project. Trimble Access Land Seismic uses these files to warn the user that he or she is in an exclusion zone.


Template Files (.TPL) contain pairs of offset inline and crossline values. In GPSeismic, these

files have several uses including auto‐offsetting in which points are moved out of exclusion zones in a prioritized manner.

In Trimble Access Land Seismic, the template file will provide the surveyor with a list of acceptable offset locations.


Appendix B – Formatting CSV Files for the Land Seismic Application

Introduction There are two different types of coordinates that will generally be input into the Land Seismic application, control points and preplot points. Due to the differences in these types of points, they will each require different types of handling when being input to the Land Seismic application. After describing each of these types of points and their unique properties, instructions for using GPSeismic to create the CSV files needed by the Land Seismic application will be provided.

Control Points Control points are used in conventional survey applications for initial points, back sight points, and check points during traverse surveys. During GNSS survey operations, control points are used to set up base stations and take check shots. For control points, it is imperative to have elevation measurements to go along with horizontal coordinates to ensure precise positioning. When importing a csv file, the Land Seismic application assumes that all coordinates, including heights, are local. Therefore, it is important for the user configure Trimble Access to use an appropriate height transformation as described in the “Coordinate Conversions” section of this document.

When adding control points to the CSV file, they should contain at least four comma delimited fields: Name, Easting, Northing, Elevation, and optionally a description.

Preplot Points Preplot data specifies the target locations in which physical evidence will be planted and survey data collected. Preplot data in seismic applications is unique in that there is usually no elevation information associated with the point. This presents two options for inputs to the Land Seismic application. The first option is to fill in all of the points with zero elevation values. The second option is to leave them empty. We recommend whenever possible that the elevation values be empty. This is critical if using the Land Seismic elevation on conventional robotic equipment, but should be used for all survey types when using the Land Seismic application.

When adding preplot points to a CSV file, they must contain at least three comma delimited fields: Name, Easting, and Northing. If elevation data is available, it should be added as a fourth field. Generally, if elevation data is not present, the three field approach is preferred. However, in the case where description information is also required, the elevation field cannot be omitted. In this case, if no elevation data is present, a question mark (?) should be used in place of elevation. In that case, each record (line) in the CSV file should include a comma delimited list containing: name, easting, northing, the question mark character or elevation if known, and finally the point description.

Note that when creating csv files for both control and preplot points, the coordinate order in the ‘Units’ section of the Trimble Access job properties must be consistent with the csv file – easting then northing, or vice versa.


Creating CSV files in GPSeismic For use in Land Seismic application to represent control or preplot points, the CSV files should contain a record for each point on a successive line, with no header lines. These points should always be comma delimited. Each point must contain at least three and up to 5 fields which are always in the same order: name, easting, northing, elevation (optional), and description (optional). The use of the elevation and northing fields within the CSV is subject to the restrictions and rules described above.

There are many places within GPSeismic to create a csv file. Most of these will take you to the ASCII Export dialog. Various examples of configuring this dialog are provided below.

For preplot data that does not require a descriptor, select only station, easting, and northing. The items to include and position/justification tabs of the ASCII Export dialog should appear as shown here.


The points should appear in Trimble Access and the Land Seismic application as shown here.

For preplot data that does require a descriptor, select station, easting, northing, descriptor, and add the question mark in the custom text field. The items to include and position/justification tabs of the ASCII Export dialog should appear as shown here.


The points should appear in Trimble Access and the Land Seismic application as shown here.


Appendix C – Trimble Access Land Seismic Application Techsheet


Appendix D – Trimble Access Project Helper Application The Trimble Access Project Helper application creates sample files for the Land Seismic Application. For normal work, these files are created by GPSeismic. For demonstrations and training scenarios, the Trimble Access Project Helper application creates working files quickly allowing the focus to remain on the Land Seismic application.

Download the utility zip file from www.gpseismic.com. This utility and set of files will create a number of files suitable for use in the Trimble Access Land Seismic application. You should follow the instructions below:

1) Unzip and place all files in a clean folder

2) Run the small executable. It should run on Windows 7 or on Windows XP on which GPSeismic or Trimble TBC is installed

3) The dialog will look like this:

4) Project Name - you should enter anything you want to identify the six files that will be created. Other parameters:

5) Make CSV Files – leave checked unless you intend on making a JOB file in GPSeismic’s QuikLoad application. If you make the CSV files, two files will be created in ‘station, easting, northing’ format. If you select the station, northing, easting option, then the file will be in that format. These are suitable for import into Trimble Access Land Seismic regardless of version. If you leave ‘the make CSV files’ checkbox unchecked, two file with a CMB extension are created instead and are easier to import into GPSeismic’s QuikLoad application for making a JOB file.

6) Scale – One of the CSV files is a 3D grid with 25 map unit station spacing and 50 map unit line spacing. These values and the values of the crooked line file are scaled by the number you enter here. For example, enter 2 to double the values.

7) Rotate – The 3D grid is by default oriented due north. Enter 1 – 359 to rotate from that.

8) Translate XY – Enter the grid coordinates for the center of the 3D grid and other files. The coordinates you enter are known grid coordinates in the coordinate system appropriate for you area. For example, UTM, State Plane 27, etc. If you are starting with a latitude/longitude, you will have to convert it to the grid coordinates of your selected system.


Six files are created: 3D Coordinate File (.CSV or .CMB if you unchecked the CSV option) 3D Grid Definition File (.GDF) - applicable to the file above Crooked Coordinate Line File (.CSV or .CMB if you unchecked the CSV option) Crooked CRK File (.CRK) - applicable to above Exclusion Zone File (.XZO) Offset Template File (.TPL) - this is an offset priority file


Appendix E – Coordinate Conversions As many of the GPSeismic files used by Trimble Access Land Seismic application have positions in local coordinates, i.e., grid definition, exclusion zone and shape, it is crucial that the coordinate system selected in the properties of a job perfectly match those within GPSeismic in both the horizontal and vertical. Coordinate systems in Trimble Access, much as in GPSeismic, consist of a local ellipsoid, datum shift, grid projection, and vertical adjustment. The datum shift is always local to/from WGS84 and can be in the form of an interpolative shift, like NADCON or NTV2, or a classical shift such as Molodensky (3 parameter) or Bursa Wolf (7 parameter). If the datum shift is classical, there exists the possibility that it will produce a change of height. For preplots, this is unimportant; however, for control points for use as GNSS base stations and check‐ins, this height change may be undesirable. Note that interpolative datum shifts never affect the height component. Furthermore, the user may choose to specify a geoid model in the form of a GGF file in the definition of the coordinate system. If so, this geoid model will be used in Trimble Access to convert to/from WGS84 ellipsoid heights and orthometric heights. For each coordinate system where the user will work, it is best to define a Template via Settings. To define a new Template, press the ‘New’ button:

Figure 58- New Button in General Survey\Settings\Templates Menu

Enter a name for this template, typically a reference to the coordinate system. Then press the button next to ‘Coord. Sys’. Choose ‘Select from library’, and select the System and Zone from the list of pre‐defined systems. Note that if your specific system or datum is not listed, you can enter the parameters manually, or use Trimble Business Center’s Coordinate System Manager to create a persistent system for your operations. Check the ‘Use geoid model’ option and choose an applicable model. Note that all Trimble Access models are in the form of .ggf files which must be placed in the ‘System’ folder of your controller.


Figure 59 - Coordinate System Settings in Trimble Access

Trimble geoid models are available for download via: http://www.trimble.com/tbc_ts.asp?Nav=Collection‐71 Note that .ggf geoid models can have their geoid heights relative to the local ellipsoid or the WGS84 ellipsoid. Most models have heights relative to WGS84. One way to confirm this is to download the ‘Geoid Model Configuration Utility’ via the link above. Then open your .ggf file and notice the interpolation method.

Figure 60- Interpolation Method Field in Geoid Model Configuration Utility

If the method is based on the WGS84 ellipsoid, then Trimble Access will use this model to go directly between orthometric and WGS84 ellipsoidal heights bypassing any height change which may be induced by the classical datum shift. If the method refers to the local ellipsoid, then both the geoid model and the datum shift will be used to convert to/from orthometric and WGS84 ellipsoidal heights. The next item to configure for the template is the units:


Figure 61 - Units Selection in Template Properties

Most of these settings are obvious; however, a critical setting is found on page 3 of 3. This is the ‘Coordinate order’ which controls the order of coordinates when importing .csv files. As we suggest creating all preplots and control points as .csv files, this setting must reflect the field order in the files you import.

Figure 62 - Select the Proper Coordinate Order in the Units Menu

Once the Template has been defined, you can use this for all jobs you create for the project.


Glossary of Terms

Access Survey – A preliminary survey to determine the locations of roads and gates for vehicles and personnel to access and travel throughout a survey area.

Accuracy Tolerance – A tolerance value for the absolute positioning quality of a surveyed point

Bin – An imaginary regular portion of a surveyed area with a unique numeric designation. The borders of a bin surround the intersection of a track line and bin line. See Figure Bin is also the stationing along a line. This term originated with geophysicists.

Bin line – Lines usually perpendicular to track lines that provide the stationing‐equivalent values.

Channel – Name for a single information stream coming from a geophone or small area geophone array.

Energy Source – Something used to vibrate the ground for the purpose of a seismic survey. These are often simply referred to as a source.

Exclusion Zone – A designated area where some activity is prohibited. Prohibited activities may vary between all access by any person or vehicle and more limited items such as “no energy source placement”.

Geophone – An energy receiver used in land seismic surveys.

Geophysicist – Someone who studies the Earth using gravity, magnetic, electrical, and seismic methods

Geophysics – The study of the Earth using quantitative physical methods.

GPSeismic – Trimble office software suite used to create preplots, postplots, and undertake a variety of geospatial operations needed to support the land survey portion of a seismic survey.

Hazard - A physical entity that requires some type of avoidance in the undertaking of a seismic survey.

LIDAR – LIght Detection and Ranging is an optical remote sensing technology that can measure the distance to, or other properties of, targets by illuminating the target with laser light and analyzing the backscattered light.

Layout – The act of placing seismic elements including geophones in preparation for a seismic survey

Layout Tolerance – The tolerance within which surveyors should try to place evidence in reference to the ideal target location. It is usually not cost effective to try to place evidence very precisely in the field. The Accuracy Tolerance is more important.

Offset – To place evidence at a desirable location when the original target location cannot be staked

Preplot – The planned or intended stakeout coordinates of a 2D or 3D seismic survey. These coordinates are sometimes called the design points.


Postplot - The actual surveyed coordinates of a 2D or 3D seismic survey resulting from real time GNSS, conventional or INS survey operations.

Prospect - Reference to the job or project area of interest.

Receiver – In surveying, refers to a survey point at which a geophone will be placed.

Seismic - of or relating to earth vibration. In seismic surveys, the source of vibration would be a vibroseis truck or dynamite charge.

Source – In surveying, refers to a survey point at which a vibroseis truck will shake or a shot hole will be drilled (and subsequently used for initiating a dynamite blast).

Shaking – A low frequency vibration created by a vibroseis truck in order to input seismic energy into the earth.

Shot - In seismic surveying, normally refers to a dynamite blast that is used to input seismic energy into the earth.

Sweep - Vibroseis truck normally shake several times in the same location. Each shaking is called a sweep. Multiple sweeps are often performed so as to use several frequencies.

Track (Trackline) – In surveying, this normally refers to the line along which a source or receiver point falls.

2D Seismic Survey – 2D data seismic surveys use sound sources (e. g., vibroseis trucks or dynamite charges) and receivers (also known as geophones) to collect data along one or more lines in order to depict the geologic strata beneath the lines(s). This method is effective for a preliminary look at the geology of an area or if offline geologic structures are not important. A line, often crooked, of geophones are deployed along the surface of the site in a 3D survey.

3D Seismic Survey - A 3D seismic survey uses sound sources (e. g., vibroseis trucks or dynamite charges) and receivers (also known as geophones) to collect data in order to depict the geologic strata beneath. 3D seismic surveys are more capable of accurately imaging reflected waves than 2D seismic surveys because it utilizes multiple points of observation. A grid of geophones and seismic source impact points are deployed along the surface of the site in a 3D survey. These grids are typically orthogonal but may also be oblique.

End of Document

trimble access land seismic guide

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