Spaceborne GPS Receivers

Design & Heritage

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 9 IGOR receivers have been deployed as primary science payload on the COSMIC mission, TerraSAR-X, Tandem-X and the TACSAT-2 missions. Additional receivers are due to be launched soon.

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.

Features

  • 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 57.6 Kbps to 2 Mbps
  • 3 Meter Accuracies Real-Time

IGOR Specifications

  • Dimensions
    • 200 mm x 240 mm x 105 mm
  • Processor
    • 2 Redundant Motorola PowerPC 603e
  • Mass
    • 4.6 kg
  • Power
    • 23 W Peak, 16 W Nominal [28 VDC +/-6 V]
  • 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
      • (Product is slowly being phased out and replaced by Pyxis Receiver)
      • Flight Units 6-8 ARO
      • (depending on requirements)

PYXIS NAUTICA

Next Generation Precision Orbit Determination + Occultation GNSS Receivers

The Pyxis Line of spaceborne GNSS receivers is the next generation of GNSS receivers based on the highly successful IGOR receiver. The Pyxis incorporates the lessons learned from the IGOR design and implements a number of improvements and upgrades made possible by recent technology developments.

The Pyxis line is based on the BRE440 CPU and a new BRE developed GNSS ASIC/FPGA. Logic miniaturazation and processing improvements allow reduction of the receiver size by at least a factor of 2 while increasing radiation and electrical performance. A new RF front-end and digital section improve signal-to-noise ratio as well as sampling resolution. The addition of L2C and L5 frequencies and eventually Galilleo frequencies provide increased Occultation Data and improved PVT resolution. Software improvements include the addition of a customer API for custom code development and the addition of GNSS Attitude determination ability.

The Pyxis receiver is available as a stand-alone receiver or 3U cPCI board LEO Precision Orbit Determination receiver (Pyxis-POD), as a Radio Occultation and POD GNSS Receiver (Pyxis-RO), and as a GEO Precision Orbit Determination receiver (Pyxis-GEO).

Pyxis-POD

  • BRE440 Processor
  • <2.0 kg
  • <20 W Peak, 16 W Nominal [28 VDC +/-6 V]
  • SEL Immune & SEU Mitigated Design
  • Attitude Determination via GNSS (Option)
  • 1 or 2 Antenna Inputs (Option 4 for AD)
  • 16 to 64 Channel GNSS Receiver
  • Position Accuracy Sub cm
  • Position Velocity Sub mm

Pyxis-GEO

PYXIS-POD / PYXIS-GEO

  • BRE440 Processor
  • <2.0 kg
  • <20 W Peak, 16 W Nominal [28 VDC +/-6 V]
  • SEL Immune & SEU Mitigated Design
  • 1 or 2 Antenna Inputs
  • Software Algorithms for POD at GEO

Typical PYXIS-POD / PYXIS-GEO Dimensions in mm

Pyxis-RO

  • BRE440 Processor
  • <4.5 kg
  • <30 W Peak, 25 W Nominal [28 VDC +/-6 V]
  • SEL Immune & SEU Mitigated Design
  • 4 to 6 Antenna Inputs
  • 48 to 128 Channel GNSS Receiver
  • Software for Open/Closed Loop Occultation
  • Tracking

PYXIS-RO to IGOR Comparison

  • About Broad Reach

    Founded in 1997, Broad Reach Engineering Company produces spaceflight hardware and software solutions, integrating vehicle design, component design and engineering services for aerospace, scientific, commercial and military customers on four continents.
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