Explorer GPS Receiver

Building on the 200+ years of on-orbit Viceroy® performance

General Dynamics’ Explorer Global Positioning System (GPS) Spaceborne Receiver provides position, velocity, and time information for Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) applications. Performance and satellite visibility are enhanced through the use of dual antennas (LEO configuration only); each of the 12 GPS channels can be assigned to either antenna. The design supports an RS-422 bus interface.

  • Design based on legacy space qualified digital design
  • 20 years of trouble-free spaceflight heritage
  • Same reliable position, velocity, time, pseudorange and carrier phase at 1Hz
  • Same form-factor and interface control as heritage Viceroy receiver


The Explorer GPS Receiver includes all the features of our heritage Viceroy GPS Receiver. The Explorer supports user selectable parts level to tailor the mission life and cost to meet most mission needs.

  • Space Qualified Digital Design
  • Full Spaceborne Capability
  • Autonomous Operation
  • Pseudorange and Integrated Carrier Phase at One Second Rate
  • One PPS Clock Output Synchronized to GPS Time
  • Radiation Tolerant Design
  • 12 Receive Tracking Channels
  • Only 56 Cubic Inches
  • 20 to 34 VDC Operation
  • Improved Radiation Tolerant Digital Electronics
  • 12 Channels Support All-in-View Tracking
  • Dual Antenna – Any Channel Assigned to Either Antenna (LEO only)
  • Fast Cold Start Mode Simplifies Integration and Autonomous Operation
  • Low Signal Acquisition and Tracking Supports GEO Sidelobe Tracking
  • Enhanced Resolution 1 Pulse per Second Output
  • Tailorable parts level



Explorer GPS Receiver Data Sheet



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Receiver Architecture 12 channels with enhanced fast acquisition processor
Dual antenna – any channel to either antenna (LEO only)
L1: 1575.42 MHz, C/A code
Carrier-aided code tracking
Based on legacy Viceroy architecture (hardware and software)

RS-422 serial I/O
X.25 protocol with ECEF position, velocity, time, longitude, latitude,
pseudorange, carrier phase
One pulse per second (GPS, UTC, or Measurement Epoch Time)
9-pin male Micro-D for prime power
25-pin female Sub-D for command and telemetry
SMA female connector for RF signal

Solution Accuracy Autonomous Position: < 15 meters, 1 sigma (LEO) | < 100 meters, 1 sigma (GEO)
Autonomous Velocity: < 0.1 meters/second, 1 sigma (LEO) | < 0.01 meters/second, 1 sigma (GEO)
1PPS time: < 100 ns, 1 sigma (typical)
Time to First Fix LEO: 4 minutes, cold start
GEO: 10 minutes, cold start
Orbital Dynamics Altitude: LEO (approx 200km to 2000km) | GEO (approx 35,800km)
Velocity: up to 16,000 meters/second
Acceleration: 1G+
Optional and Custom Features:
Contact Factory
Time Strobe Input: < 100 ns, 1 sigma
Precision internal reference Ovenized Crystal Oscillator (OCXO)
Enhanced Radiation Hardening
Physical/Environmental Size: 6.3 x 5.2 x 1.7” (160 x 132 x 43 m)
Weight: 2.5 lbs (1.2 kg) max
DC Power: 8 W max steady state tracking (22-34vdc)
Vibration: 17 grms
Shock: 3000 G
Temperature: -20°C to +60°C
Radiation Tolerant Design
Single Event Latch-up Immune


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