1. THEMIS/GBO Engineering Peer Review 1 UCB, Oct. 17, 2003 Ground Based Observatories (GBO) Observatory System Design Stewart Harris - UCB

2. THEMIS/GBO Engineering Peer Review 2 UCB, Oct. 17, 2003 System Design Summary Presentation Overview: Observatory Specifications GBO Observatory Components –Power Control Unit –Temperature Control –Power Control –Instrument Data Acquisition and Transmission –System Computer –Satellite Communication Environmental Enclosure –Requirements –Design

3. THEMIS/GBO Engineering Peer Review 3 UCB, Oct. 17, 2003 GBO Components Main AC Power GMAG Telesat Dish Iridium GPS All Sky Imager in Enclosure Computer System Enclosure & Observatory Support Electronics Internet Variations possible at some sites: Existing magnetometer Enclosures not needed Existing Internet connection

4. THEMIS/GBO Engineering Peer Review 4 UCB, Oct. 17, 2003 Ground Site Requirements REQUIREMENTSYSTEM DESIGN GB.GS-1: GBO sites shall provide largely unobstructed viewing over 160° hemisphere. Compliance. Site selection criteria GB.GS-2: GBO sites shall be reasonably clear of local magnetic interference. Compliance. Site selection criteria GB.GS-3: Each GBO site shall provide power, 120 VAC, single phase, 60Hz, at least 10A service Compliance. Site selection criteria GB.GS-4: Each GBO site shall have a local custodian available for periodic maintenance and Level 0 data retrieval Compliance. Site selection criteria

5. THEMIS/GBO Engineering Peer Review 5 UCB, Oct. 17, 2003 Observatory Requirements REQUIREMENTSYSTEM DESIGN GB.OBS-1: Shall provide unattended operation of instruments, data acquisition and storage for up to 4 months per observation season Compliance. Will operate for 12 months/yr GB.OBS-2: Shall provide interface to enable periodic upload of new observation parameters and operating software. Compliance. Internet connectivity provides secure login and file transfer GB.OBS-3: Shall provide digital interfaces and digital data storage for the ASI and GMAG. Compliance. Linux OS supports serial, USB, 10BaseT, etc. GB.OBS-4: Shall provide a GPS receiver for geographic position calibration and time stamp Compliance. GPS included in GMAG subsystem, provides better than 50ms accuracy. Synchronous image acquisition. GB.OBS-5: Shall provide a means for daily uplink of Level 1 (compressed) data, at least 3MB/day Compliance. Satellite Internet connection has demonstrated 10kbps sustained uplink. Provides > 100MB/day GB.OBS-6: Observatory shall store high resolution, Level 0 data locally on hard drives, at least 24GB/month Compliance. USB (or Firewire) drives, 80GB to 120GB, will be periodically swapped by site custodian. Selective transfer of high res. data via Internet is also planned GB.OBS-7: Observatory shall be compatible with locally provided power Compliance. 120 VAC, 60Hz, 10A service, backed up by UPS. UPS sized for 1 hour battery operation (excl heaters) GB.OBS-8: Shall provide controlled power-up and power- down of instruments and system computer automatically Compliance. System power and shutdown/re-boot sequencing controlled by independent control processor GB.OBS-9: Operate in external ambient temperatures range from -50° to +40°C Compliance. Enclosures, insulation, heaters and control designed to keep internal temperatures at 20º ± 10º C GB.OBS-10: Shall survive transport to site and provide stable mounting at the site Compliance. Yes

6. THEMIS/GBO Engineering Peer Review 6 UCB, Oct. 17, 2003 System Electrical Overview

7. THEMIS/GBO Engineering Peer Review 7 UCB, Oct. 17, 2003 Prototype OSE Layout 28” Rack Mount Shipping Case System Computer GMAG Interface Electronics Hot Swap HDD Space available for modems UPS

8. THEMIS/GBO Engineering Peer Review 8 UCB, Oct. 17, 2003 Prototype OSE Layout (2) Power Control Unit CR10X Datalogger UPS Camera Power Supply CR10X Battery

9. THEMIS/GBO Engineering Peer Review 9 UCB, Oct. 17, 2003 Power Control Unit (PCU) Design Approach Provide temperature environment inside Computer Enclosure and ASI that enables use of standard commercial hardware for computer, USB hard drives, Telesat/Starband gear, etc. –Maintain internal temperatures at 20º ± 10º C –Implement graceful shutdown in either event of: –Loss of Power –Loss of Temperature (either too high, or too low) –In the event of extended power loss, power control must allow for temperature to stabilize prior to re-boot Select “Smart” controller (CR10X) vs Thermostat approach –Programmable with remote access via Internet or Iridium –Provides analog I/O, digital I/O for System Computer –Extended temperature range (-55º to +85ºC) –Always operating and accessible –Low power consumption (battery can operate it for months) –Simple programming and data logging capability The PCU provides control of both Temperature and Instrument Power

10. THEMIS/GBO Engineering Peer Review 10 UCB, Oct. 17, 2003 Heating and Cooling Control CR10X Temperature Sensors ASICSEOutside AC Power Analog I/O Digital I/O System Computer Serial I/O Main AC V LINE CSE Heater SSRs ASI Heater CSE Cooler CB1 Power Control Unit

11. THEMIS/GBO Engineering Peer Review 11 UCB, Oct. 17, 2003 CSE Heating / Cooling Devices Small Space Heaters 175W, 120VAC, 2 ea Solid State Air Conditioner 163W Capacity 120VAC Power

12. THEMIS/GBO Engineering Peer Review 12 UCB, Oct. 17, 2003 ASI Heating Devices Heat Blankets 120W, 120VAC, 2 ea

13. THEMIS/GBO Engineering Peer Review 13 UCB, Oct. 17, 2003 System Power Control CR10X can initiate System Shutdown: Monitors voltage (V LINE ) and temperature (T CSE ) continuously Flag System Computer to shutdown via serial line protocol In event of power loss –Monitors time “on-battery”, flags shutdown after 60 (TBR) min. –When power returns, allows temperature to stabilize, then restores System Power In event of temperature loss (either too cold, or too hot) –Initiates immediate shutdown –Restores System Power when temperatures within limits

14. THEMIS/GBO Engineering Peer Review 14 UCB, Oct. 17, 2003 Instrument Data Flow System Computer ASI GMAGTelesat Modem Hot Swap Hard Drive(s) USB Serial I/O 10/100 Base T GPS Internet

15. THEMIS/GBO Engineering Peer Review 15 UCB, Oct. 17, 2003 System Data Collection System Computer Selection Hardware features: see next slide Compatible with a Linux standard installation Reasonably low power (30 – 40W) Reasonable size Alternatives examined: –Databrick (MobilePIII 700MHz) – used in Prototype –Thermal issues, requires modification to include a fan –SC240 Mini-ITX based (VIA chipset 600MHz C3) –Concerns about VIA support in future Linux upgrades –Fanless! –Nova7895 based (PIII 866MHz) –Rather large, but workable –More expensive than SC240

16. THEMIS/GBO Engineering Peer Review 16 UCB, Oct. 17, 2003 Computer Comparison Serial USB v1 LAN GMAG GPS ASI Swappable HDD Satellite Internet CR10X TOTAL NEEDED 1 USB v2 1 1 Databrick SC240 NOVA-7895 2201 4042 32 1 Firewire 2 1 1 1 POWER Custodian Connect 1 32W 39 2212 COMPUTER PORTS AVAILABLE ? COMPUTER PORTS NEEDED COST $1317 $940 $1216 Single Piece Price

17. THEMIS/GBO Engineering Peer Review 17 UCB, Oct. 17, 2003 Remote Intervention Two Levels: Typically GBO accessed via Internet –Hardwired in several locations –Using local LAN connection –Telesat HSi (Canada) or Starband 480 (Alaska) –Can provide fixed IP address –Tests indicate about 10kbps sustainable uplink rate Under duress, Back up communication via Iridium –Reserve for remote locations? –2400 bps

18. THEMIS/GBO Engineering Peer Review 18 UCB, Oct. 17, 2003 Iridium Connection System Computer Serial Port SwitchIridium Modem CR10X Serial I/O Supervisor Channel 2 Supervisor Channel 1 UCB

19. THEMIS/GBO Engineering Peer Review 19 UCB, Oct. 17, 2003 The Environment USGS Tundra monitoring site Alaskan Tundra Summerand Winter

20. THEMIS/GBO Engineering Peer Review 20 UCB, Oct. 17, 2003 Enclosure Concept “Box within a Box” Internal Rack Mount for Equipment (Doubles as Shipping Case) External Insulated Environmental Enclosure

21. THEMIS/GBO Engineering Peer Review 21 UCB, Oct. 17, 2003 Computer Sys. Enclosure (CSE) Requirements: House Observatory Support Electronics in Controlled Environment –ASI, GMAG, Computer, Communications, Control, etc. Maintain internal temperature at 20º ± 10º C Operate in external ambient of -50º to +40ºC Provide “dust-free” method of cooling when required External Cable access via “stuffing tube” Provide access door for Hard Drive Hot Swap Provide access for maintenance Ruggedized and shock protection for transportation

22. THEMIS/GBO Engineering Peer Review 22 UCB, Oct. 17, 2003 Prototype Computer Enclosure

23. THEMIS/GBO Engineering Peer Review 23 UCB, Oct. 17, 2003 Heating/Cooling Needs Heating Required: Outside temp: -60º C Inside temp: +10º Heat added: 165 W Cooling Required: Outside temp: +50º C Inside temp: +40º Heat to remove: 80 W Assumptions: Enclosure dimensions: 34” (h) x 44” (w) x 44” (l) Thermal resistance (R-value): R-12 Internal power dissipation: 47 W Prototype GBO Athabasca

24. THEMIS/GBO Engineering Peer Review 24 UCB, Oct. 17, 2003 Prototype Findings Prototype CSE Deployment: Current design size is larger than necessary. –Prototype size: 43” (L) x 45” (W) x 38” (H) –Could be smaller for easier transport. –Minimum size: approx. 37” (L) x 40” (W) x 38” (H) “Awning” design needs improvement. Keeping it warm inside has proven to be easy Keeping it cool inside may be more difficult, but the solid state A/C seems to work. Athabasca 4/15/04 courtesy M. Greffen

25. THEMIS/GBO Engineering Peer Review 25 UCB, Oct. 17, 2003 END

26. THEMIS/GBO Engineering Peer Review 26 UCB, Oct. 17, 2003 PCU Programming CR10X Software: Table of Instructions Loops on fixed interval High level instructions Example

27. THEMIS/GBO Engineering Peer Review 27 UCB, Oct. 17, 2003 System Power State Diagram