(Interface Control Document for GPS User Equipment) is a technical standard published by the U.S. Space and Missile Systems Center (SMC). It defines the electrical, mechanical, and data protocol interfaces between a GPS receiver and an external host system (e.g., a navigation computer, weapon system, or display unit). Unlike consumer-oriented NMEA 0183, ICD-GPS-153 is designed for high-integrity, high-update-rate military and aviation applications .
Delivers North-East-Up (NEU) velocity vectors or Earth-Centered Earth-Fixed (ECEF) rates.
If you are building a system for 2025 and beyond, ensure your implementation of ICD-153 references the latest revision that supports M-code handover. Do not rely on a 1992 copy of the specification. icd-gps-153 protocol
To truly appreciate ICD-GPS-153, you must understand what it is not .
The 16-bit CRC (polynomial 0x1021, initial value 0xFFFF) covers all bytes from sync to the end of the data field (excluding the sync bytes themselves? No – check standard: The CRC includes the message ID, length, and data fields. Some implementations also include sync – verify against receiver manual). Always test against a known trace. (Interface Control Document for GPS User Equipment) is
In the world of military and aerospace navigation, precision is non-negotiable, and reliability is the ultimate currency. While most consumer devices rely on simple NMEA sentences over Bluetooth or USB, mission-critical platforms—from fighter jets to unmanned surface vessels—operate on a different, far more rigorous standard. This standard is known as .
While most consumer GPS protocols only "push" data to a screen, ICD-GPS-153 allows for full duplex communication where the host system can send commands back to the receiver. Technical Characteristics Physical Layer: It typically operates over serial interfaces, specifically Protocol Name: It is often referred to as the GPS Standard Serial Interface Protocol (GSSIP) Data Content: The protocol handles various data types, including: 3D Position (Latitude, Longitude, Altitude). Velocity and Time of Day. Satellite health and status. Waypoints and mission-specific parameters. Common Applications You will find this protocol in hardware such as the Precision Lightweight GPS Receiver (PLGR) Defense Advanced GPS Receiver (DAGR) Do not rely on a 1992 copy of the specification
| ID (hex) | Name | Description | |----------|------|-------------| | 0x0010 | Position/Status | Latitude, longitude, altitude, fix type, number of satellites | | 0x0012 | Velocity | East, north, up velocities (m/s) | | 0x0015 | Time | UTC/GPST time, date, time-of-week, leap seconds | | 0x0016 | Satellite Info | PRN, elevation, azimuth, SNR, health for up to 12 satellites | | 0x0019 | PPS Status | 1PPS synchronization accuracy (ns) | | 0x0024 | Raw Measurement | Pseudorange, carrier phase, Doppler (for external RTK/post-processing) |