Sentinel M-Code GPS Receiver

Accurate military code certified positioning service in space

General Dynamics’ Sentinel® M-Code GPS Receiver provides Precise Positioning Service position, velocity, and time information for Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) applications. MEO and HEO orbits are also available. Performance and satellite visibility are enhanced through the use of dual antennas; each of the 64 GPS channels can be assigned to either antenna.

  • Design Based on Legacy Monarch™ GPS Receiver Space-Qualified Digital Design
  • 1,000+ Equivalent Years of Accumulated Trouble-Free DoD Space Heritage; > 6M Orbits
  • Same Reliable Position, Velocity, Time, Pseudorange and Carrier Phase @ 10 Sec Optional


  • Optional Relative Navigation Position, Velocity, and Time Modes
  • RS-422 I/O interface and control, protocol similar to our Legacy Viceroy® C/A Receiver
  • Optional MIL-STD-1553B Interface & Control, protocol similar to our legacy Monarch-M P(Y) code receiver
  • LEO, GEO capable with MEO and HEO option
  • GEO Sidelobe Acquisition and Tracking Algorithms enable continuous PNT availability
  • Fast Acquisition Processor enables rapid COLD start capability
  • Integrated Anti-Jam Technology and anti-spoof algorithms enable superior performance in GPS contested and denied environments.
  • 64 Channels, L1 and L2 Capable
  • C/A, P(Y) and Modernized M-Code, with optional L2C civil signal
  • Provides Near Real-time Position, Velocity and Time Measurements for Superior User Performance
  • Relative Navigation Capability Allows for Differential Position, Velocity and Time Determination Between Co-orbiting Spacecraft (Optional)
  • Precision Time Stamping Allows Unprecedented Accuracies in Space
  • Precise Position Service Key Management Supports All Selective Availability Anti-spoof Module (SAASM) Unique Keying
  • Single or Dual Antenna Capability Allows the Spacecraft User Installation Flexibility and Performance
  • Qualified and Tested for the Space Environment: Pyrotechnic Shock, Random Vibration, Thermal-vacuum and EMI/EMC (Tailored Mil-Std-461F)


Sentinel M-Code GPS Receiver Data Sheet

View Document

Receiver Architecture

64 Channels PPS-GPS C/A, P(Y), M-Code Channels, L2C available as an option
Dual Antenna – any channel to either antenna
Frequencies & Codes: L1 & L2, C/A Code, P(Y), M-Code, L2C optional
Narrow Bandwidth Acceleration-Aided Carrier/Code Tracking
Tracking, and Navigation Algorithms based on Monarch-M GPS Receiver
Kalman Filter-based navigation solution with integrated high fidelity orbit propagator bridges gaps between GPS outages
On-Orbit Software Reprogrammable

Input / Output RS-422, Follows Legacy Viceroy Receiver ICD (Optional: MIL-STD-1553B, Follows Legacy Monarch / Monarch-M™ ICD)
One Pulse per Second (GPS, UTC, or Measurement Epoch Time)
Time Stamp Input Signal, measures the time of an external pulse
LEO Solution Accuracy Autonomous Position: 4.0 meters, 1 sigma, < 1 meter typical
Autonomous Velocity: < 2 cm/sec, 1 sigma, < 0.5 cm/sec typical
Clock and 1PPS Absolute: < 50 ns 1 sigma, < 5 ns typical
Time Strobe Input: < 50 ns, 1 sigma
Optional Relative PVT Mode: 0.5m, 0.5 cm/sec, 4 ns (1 sigma)
GEO Solution Accuracy Autonomous Position: 25 meters, 1 sigma, < 5 meter typical
Autonomous Velocity: < 2 cm/sec, 1 sigma, < 0.5 cm/sec typical
Clock and 1PPS Absolute: < 50 ns 1 sigma, < 5 ns typical
Time Strobe Input: < 50 ns, 1 sigma
Cold Start Time to First Fix (self-test complete & assumed keyed) LEO < 10 minutes, 67% probability, 4 min typical
GEO < 15 minutes, 90% probability, 8 min typical
Orbital Dynamics Altitude: LEO, GEO (200 km – 45,000 km), MEO & HEO Optional
Velocity: up to 16,000 meters/second
Acceleration: 1G
Optional and Custom Features External Reference Oscillator or Internal Precision
GEO Sidelobe Acquisition and Tracking Software
High Dynamics Acquisition & Tracking
Physical/Environmental Radiation: 100 Krads
Single Event Upset: < 1 per year
Single Event Latchup: Immune
Reliability: 0.90, 10 year, 30°C Baseplate, 100% duty cycle
Vibration: 16.6 Grms
Pyro Shock: 2000 G
Temperature: -34°C to +71°C
Size: 180 x 160 x 60 mm-Envelope
Weight: < 2.5 kg
DC Power: < 9 w typical LEO (dual antenna), < 8 w typical GEO (single antenna)

The Next Generation of Secure Position, Navigation and Timing Technology Whitepaper

The Department of Defense is now focused on satisfying the need to provide assured position, navigation and timing (PNT) – or assured PNT – and General Dynamics is answering that call by developing new antenna designs, power amplifiers, receivers, waveform generators and related capabilities that are more resilient to threats.

Download The Whitepaper

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