TOP - GNSS/GPS Receivers - Integrated GPS Occultation Receiver
         
The IGOR design is based on the NASA/JPL Black Jack space-borne GPS Receiver. The Black Jack receiver is a revolutionary spaceflight Global Positioning System (GPS) receiver developed by NASA/JPL to fill future needs for orbit-based GPS science.

The IGOR design continues the evolution of the Black Jack receiver and previous units and incorporates several improvements based on the experiences made with the Black Jack on previous NASA/JPL missions including CHAMP, SAC-C, Jason-1, and GRACE. To date six IGOR receivers have been deployed as primary science payload on the COSMIC mission. Additional receivers are due to be deployed in late 2006 on-board the TerraSAR-X and TACSAT-2 missions.
         
Features   Igor Specifications    
  • GPS Internally Redundant (Digital Processors and DC-DC Converters)
  • Based on PowerPC 603e CPU
  • Dual-Frequency L-Band
  • Dual POD Antennas
  • Dual Occultation Antennas
  • Solid State Recorder - 128 MBytes
  • Integrated Payload Controller
  • 4 RS-422 Inputs, Cmd/Tlm rates from 57.6Kbps to 2Mbps
  • 3 Meter Accuracies Real-Time
 

Dimensions:
200mm x 240mm x 105mm

Processor:
2 Redundant Motorola PowerPC 603e

Mass:
4.6kg

Power:
23W Peak , 16W Nominal [28 VDC +/-6V]

Radiation:
TID - Estimated 12Krad at Low Dose Rates (Satellite Shielding not Included).
SEL - No Destructive Latch at 40 MeV
SEU - Designed for Tolerance & Recovery

Availability:
Now
FLIGHT Units 6-8 ARO
(depending on requirements)
         
GPS Occultation Science        
A technique relying on the simple fact that a planet's atmosphere acts much like a variable density lens, bending and slowing the propagation of microwave signals passing through it from the Ionosphere down to the surface. The lens effect results from decreasing atmospheric density with altitude. If the positions of transmitting and receiving satellites are precisely known, the "atmosphere delay" can be measured precisely, the time derivative of which (Doppler) can be inverted to give atmospheric density vs. altitude information. The IGOR Occultation GPS Receiver is designed to meet all the requirements of such occultation science experiments. In addition, the IGOR also provides the functionality of a POD GPS receiver with a payload controller, and a solid state recorder.