27 Octobre 2014

Caractéristiques de l'instrument DORIS DGxx

  • High precision Doppler measurements and on-board navigation
  • provides elementary velocity measurements with an accuracy better than 0.3mm/s
  • delivers real time PVT information in ITRF and J2000 reference frames with sub metric to centimeter accuracy depending on orbit and spacecraft characteristics
  • capacity to provide geodesic data to help altimeter tracking
  • Beacons tracking capability
  • up to 7 beacons simultaneously (7 dual frequency channels)
  • Autonomous operation
  • routine high precision navigation mode reached autonomously
  • only Maneuver prediction TC needed in routine, if any
  • Power supply
  • 22 - 37 V DC
  • 23 W typical; 30 W at Warm up, less than 2 hr
  • Telemetry/Telecommand Interface
  • MIL-STD-1553 / CCSDS packet terminal protocol
  • max TM rate < 4kbits/s (all TM activated)
  • 2 Bi-Level status per chain (power and software status)
  • 10 MHz reference signal distribution
  • high stability
  • monitored with an accuracy of 10-12
  • Internally cross-strapped
  • On board time tagging capacity
  • external pulse time tagging capacity or pps distribution
  • microsecond accuracy W.r.t. International Atomic Time Scale
  • CPU/SW
  • rad tolerant design with SPARC ERC32 processor and memory fault detection and recovery
  • whole software stored twice in 2 redundant banks of EEPROM ; may be fully uploaded w/o any mission interruption