themis/gbo cdr peer review 1 univ.of calgary, apr. 26-27, 2004 ground based observatories (gbo) cdr...

THEMIS/GBO CDR Peer Review 1 Univ.of Calgary, Apr. 26-27, 2004

Ground Based Observatories(GBO)

CDR Peer Review

S. B. Mende

University of California - Berkeley


GBO Team Institutions

University of California – Berkeley (UCB)• S. B. Mende – GBO science lead

• Provides ASI development, system engineering, GBO system fabrication and construction, data archive and dissemination

University of California – Los Angeles (UCLA)• C. T. Russell – magnetometer science lead

• Develop and provide ground magnetometer for GBO / EPO

University of Calgary• E. Donovan – Canadian science lead

• Providing GBO system deployment in Canada, field management, data collection, development participation

University of Alberta• I. Mann – magnetometer scientist

• Providing access to Canadian magnetometer network


GBO / UCB Organization

GBO Lead Co-InvestigatorS. B. Mende

510-642-0876

GBO Lead Co-InvestigatorS. B. Mende

510-642-0876

AdministratorYa Ling Zhu510-643-5176

AdministratorYa Ling Zhu510-643-5176

Project ManagerS. Harris

510-643-3395

Project ManagerS. Harris

510-643-3395

Test & Verif.H. Frey

Test & Verif.H. Frey

System Eng.S. Harris

System Eng.S. Harris

MechanicalG. Dalton

MechanicalG. Dalton

SoftwareS. Geller

SoftwareS. Geller

AssemblyB. Dalen

AssemblyB. Dalen

Electrical TestTBD

Electrical TestTBD

UCB Organization


GBO/EPO Magnetometer Organization

Lead Co-InvestigatorC. T. Russell310-825-3188

Lead Co-InvestigatorC. T. Russell310-825-3188

R & QAD. Dearborn310-825-1488

R & QAD. Dearborn310-825-1488

Business OfficeJ Nakatsuka310-825-3939

Business OfficeJ Nakatsuka310-825-3939

Program ManagerD. Pierce

775-588-0356

Program ManagerD. Pierce

775-588-0356

MagneticsR. Snare

MagneticsR. Snare

AnalogD. Pierce

AnalogD. Pierce

MechanicalG. Barr

MechanicalG. Barr

DigitalD. Dearborn

DigitalD. Dearborn

AssemblyW. Greer

AssemblyW. Greer

UCLA Organization


GBOs: A synoptic view of the aurora

Global auroral image taken by IMAGE WIC.

Proposed THEMIS GBO sites superimposed.


GBO Science Objective

GBO shall monitor the auroral light and ionospheric currents across North America in order to localize the time, location, and evolution of the auroral manifestation of the substorm.

Themis mission requirement relating to GBO: Determine substorm onset time and substorm meridian magnetic local time (MLT) using All Sky Imagers (one ASI per MLT hr) and Ground Magnetometer (two GMAG per MLT hr) with t_res<30s and dMLT<1° respectively, in an 8hr geographic local time sector including the US.


GBO Derived Requirements

Requirement Performance1. Shall cover 8 hrs of Geographic Local Time

over North American segment (allows continuous 12 hr conjunctions with probes)

Covers 10 hrs of Geographic LT with ASIs, 14 hrs with GMAGs incl. Non-Themis Contributions

2. Shall include at least one ASI per MLT hour within this geographic segment

Two ASIs per hour (MLT)

3. Shall include two auroral GMAG per hour (MLT) (high/low lat.) within this segment.

More than two GMAGs per hour (MLT) (New + existing)

4. Timing accuracy of phenomena observed shall be better than 10s absolute

1s ASI exposures. Cadence: 0.5s GMAG, 3 -5s ASI. Accuracy: <50 ms (GPS)

5. ASI sensitivity: Detectable response for aurora shall be < 10kRayleigh

< 1kR (5:1 S/N ratio)

6. Sensitivity of GMAG instrument shall be < 1nT

0.1nT

7. The spatial resolution shall be sufficient to locate the substorm brightening with an accuracy of 100km (dMLT < 1°)

ASI data compressed data (Stream 1) provides 0.5° sampling.


Implementation Plan

GBO Program Implementation:• Integrate ASI from UCB, GMAG from UCLA with site prep

and deployment provided by U. Calgary• Build, calibrate and qualify first unit within one year after

start of Phase B• Five sites shall be installed two winters before THEMIS

launch• Total GBO installed network shall be 20 sites, installed one

winter before THEMIS launch


GBO Site Locations

IMAGE FUV substorm onset identification.Of events indicated within GBO longitude sector, 2% are outside the latitude covered


GBO Site List - Today

No. Site Abbrev. Location Latitude Longitude GMAG type1 Gakona GAK USA 62.4 214.8 Themis62 Fort Yukon FYU USA 67 199.6 Themis43 Mcgrath MCGR USA 63 204.4 Themis24 Kiana KIA USA 66.6 214.7 Themis55 Inuvik INUV Canada 68.3 226.7 CGSM ('06)6 White Horse WHOR Canada 60.7 224.9 Themis77 Lac de Gras LGRA Canada 64.6 250 Contwoyto(?)8 Fort Simpson FSIM Canada 61.8 238.8 CGSM9 Prince George PGEO Canada 53.9 237.4 Themis1

10 Rankin Inlet RANK Canada 62.8 267.9 CGSM11 Fort Smith FSMI Canada 60 248.1 CGSM12 Athabasca ATHA Canada 54.7 246.7 NRCan13 Gillam GILL Canada 56.4 265.4 CGSM14 The Pas TPAS Canada ? ? Themis315 Pinawa PINA Canada 50.3 264 CGSM16 PBQ PBQ Canada 55.3 292.3 NRCan17 Kapuskasing KAPU Canada 49.4 277.6 ??18 Nain NAIN Canada 56.5 298.3 Themis919 Gangon GANG Canada 51.9 291.8 Themis820 Goose Bay GBAY Canada 53.3 299.6 Themis10


GBO Site Location Deployment


Observatory Design

Major components:• Science Instruments:

– All Sky Imager (ASI)

– Ground Magnetometer (GMAG)

– GPS

• Observatory Equipment– Communications

– Environment Control

– System Computer


GBO Components

AC Power

GMAG

Telesat Dish

Iridium

GPS

All Sky Imager

Computer Enclosure

Internet

Variations possible at some sites:

Existing magnetometer

Enclosures not needed

Existing Internet connection


All Sky Imager

Overview:• Design

• Specifications

• Interface

• Data Products


All Sky Imager Heritage

• Environmental protection/deployment and automation drawn from AGOs (flawless multi-year operation in Antarctica).

• Prototype camera field tested in Canada

– Demonstrated high cadence, high sensitivity

– Taking 5s images


• ASI primary image 290 pixel diameter is “binned” to 0.5° resolution (thumbnails)

• Primary science data:

Level 1 (~ 1kbps)(incl GMAG, housekeeping)

• Available via SAT comm, either Telesat (Internet real-time) or Iridium (daily)

• High resolution data:

Level 0 (180 kbps)

• Selective downloads via Satellite Internet

• Periodic collection via disk swapping

ASI Data Products


Ground Magnetometer

Overview:• Specifications

• Design

• Data Products

• Software

• GBO & E/PO


Results from Peer Review

Comments from reviewers were positive:• “review was conducted with quality information”• “details of the system were well engineered”• “detailed consideration of environmental accommodation”• “Success is likely given the proposers’ excellent experience and track

record.”• “likely to accomplish not only the THEMIS mission, but also provide a

wealth of data for auroral research in general.”• “applaud the team for their emphasis on a web based real time delivery

of…data”• “Overall plan and direction seems good.”• “Early deployment, beginning this coming winter, is good idea”

Reviewers also provided several recommendations…


Peer Review Action Status, 1

Request / Recommendation Impact / Discussion Status

1 Synchronize ASI exposures (5s cadence) across entire network to 100ms

Given GPS accuracy, can be implemented with software change. Minimally complex.

Will comply

2 Generate a Keogram (1min res.) from high resolution images on a daily basis

Increases daily processing load on system computer at each site. Low impact.

Will comply

3 Generate a sky clarity index to aid image interpretation.

Several approaches are under investigation.

On-going analysis

4 Bury exposed cables, as safety precaution and protection from animals.

Great idea. Will comply

5 Find local caretakers. It will be difficult (and expensive).

This is planned. Local custodians are REQUIRED, to perform routine maintenance, e.g. snow removal.

Will comply

6 Be prepared, at remote sites, for power of low quality, frequent outages, variations in voltage / freq.

Requires UPS and power conditioning, but ultimately, individual GBO will be off-line during extended power outage.

Will comply


Peer Review Action Status, 2

Request / Recommendation Impact / Discussion Status

7 Maintain formal log giving station status, configuration, caretaker interventions, etc.

This is planned. Implementing caretaker database will require manual data entry.

Will comply

8 Plan now for selective transfer of high resolution data.

This has been recognized as highly desirable from the beginning.

Will comply

9 Increase thermal capacitance of enclosures to slow down temperature loss during power outage.

This also has been recognized as highly desirable, and part of the design consideration.

Will comply

10 * Establish System Requirements Specification document

GBO requirements are currently included in THEMIS MRD

Will comply

11 * Establish Systems Interface Specifications document

Interfaces with ASI, GMAG, communications, power, data center will be included.

Will comply

12 * Establish System Test Plan document

Test and verification of each installation is planned, in addition to qualification testing.

Will comply

* Request for Action

themis/gbo cdr peer review 1 univ.of calgary, apr. 26-27, 2004 ground based observatories (gbo) cdr...

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