Post on 12-Jan-2016
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
THEMIS/GBO CDR Peer Review 2 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 3 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 4 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 5 Univ.of Calgary, Apr. 26-27, 2004
GBOs: A synoptic view of the aurora
Global auroral image taken by IMAGE WIC.
Proposed THEMIS GBO sites superimposed.
THEMIS/GBO CDR Peer Review 6 Univ.of Calgary, Apr. 26-27, 2004
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.
THEMIS/GBO CDR Peer Review 7 Univ.of Calgary, Apr. 26-27, 2004
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.
THEMIS/GBO CDR Peer Review 8 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 9 Univ.of Calgary, Apr. 26-27, 2004
GBO Site Locations
IMAGE FUV substorm onset identification.Of events indicated within GBO longitude sector, 2% are outside the latitude covered
THEMIS/GBO CDR Peer Review 10 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 11 Univ.of Calgary, Apr. 26-27, 2004
GBO Site Location Deployment
THEMIS/GBO CDR Peer Review 12 Univ.of Calgary, Apr. 26-27, 2004
Observatory Design
Major components:• Science Instruments:
– All Sky Imager (ASI)
– Ground Magnetometer (GMAG)
– GPS
• Observatory Equipment– Communications
– Environment Control
– System Computer
THEMIS/GBO CDR Peer Review 13 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 14 Univ.of Calgary, Apr. 26-27, 2004
All Sky Imager
Overview:• Design
• Specifications
• Interface
• Data Products
THEMIS/GBO CDR Peer Review 15 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 16 Univ.of Calgary, Apr. 26-27, 2004
• 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
THEMIS/GBO CDR Peer Review 17 Univ.of Calgary, Apr. 26-27, 2004
Ground Magnetometer
Overview:• Specifications
• Design
• Data Products
• Software
• GBO & E/PO
THEMIS/GBO CDR Peer Review 18 Univ.of Calgary, Apr. 26-27, 2004
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…
THEMIS/GBO CDR Peer Review 19 Univ.of Calgary, Apr. 26-27, 2004
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
THEMIS/GBO CDR Peer Review 20 Univ.of Calgary, Apr. 26-27, 2004
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