February 7, 2017

DORIS DGxx Instrument characteristics

  • High-precision Doppler measurements and onboard navigation
  • Provides elementary velocity measurements with an accuracy better than 0.3 mm/s
  • Delivers real-time PVT information in ITRF and J2000 reference frames with submetric to centimetre accuracy, depending on orbit and spacecraft characteristics
  • Capacity to provide geodetic data to help altimeter tracking
  • Beacon tracking capability
  • Up to 7 beacons simultaneously (7 dual-frequency channels)
  • Autonomous operation
  • Routine high-precision navigation mode reached autonomously
  • Only manoeuvre prediction TC needed in routine mode, if any
  • Power supply
  • 22 - 37 V DC
  • 23 W typical; 30 W at Warm-up, less than 2 hours
  • Telemetry/Telecommand Interface
  • MIL-STD-1553 / CCSDS packet terminal protocol
  • Max TM rate < 4kbps (all TM activated)
  • 2 Dual-Level statuses per chain (power and software status)
  • 10-MHz reference signal distribution
  • High stability
  • Monitored with an accuracy of 10-12
  • Internally cross-strapped
  • Onboard time tagging capacity
  • External pulse time-tagging capability or pps distribution
  • Microsecond accuracy with respect to 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 without any mission interruption