If "153" was a typo for "200," this is the fundamental protocol for the Global Positioning System. It is the document that defines the "L1" and "L2" carrier frequencies, the C/A (Coarse/Acquisition) code, and the P(Y) (Precise) code.
You cannot find ICD-GPS-153 on a public website. It is (Export Controlled) or higher. You must have a U.S. government contract, a Non-Disclosure Agreement (NDA) with the DoD, and a valid export license (for non-U.S. entities). Request it via the GPS Support Center or your prime contractor.
This article is for informational purposes. Actual implementation of ICD-GPS-153 requires authorization from the U.S. Department of Defense and adherence to ITAR/EAR regulations.
Tactical GPS systems and ground-based receiver modules (GB-GRAM) often feature multiple serial ports, where some are dedicated to ICD-GPS-153 for control/status and others to NMEA for standard position data. Accessing the Specification icd-gps-153 protocol
The ICD-GPS-153 protocol supports high-security, robust defense applications:
Organizations seeking technical details must submit a formal GPS Technical Library Document Request . This request requires a signature from an approved GPS Program representative or the U.S. Coast Guard Navigation Center. These requests are limited to validated defense contractors and authorized government entities with an active Need-to-Know status.
The ICD-GPS-153 protocol is a master-slave protocol, where the GPS receiver acts as the slave device and the host device acts as the master device. The protocol uses a binary data format, with each message consisting of a header, a payload, and a checksum. If "153" was a typo for "200," this
: Frequently used in tactical sensors like the VectorNav VN-210 to interface with external military GPS units. Standard Message Examples
: Correlates the exact Coordinated Universal Time (UTC) or GPS time-scale epoch with the hardware 1PPS pulse.
Deploying equipment using the ICD-GPS-153 standard requires specialized hardware profiles: GSSIP Message Format - Safran - Navigation & Timing It is (Export Controlled) or higher
At the heart of this ecosystem lies a document and a protocol designated . For engineers, defense contractors, and systems integrators working with the United States Space Force (USSF) and NATO allies, ICD-GPS-153 is not just another specification; it is the definitive blueprint for interfacing with high-precision, secure GPS receivers for weapon systems, aircraft, and naval platforms.
The ICD-GPS-153 protocol is expected to undergo further updates and modernizations to address emerging challenges and requirements:
To support legacy systems without requiring a live, hardware-controlled cryptographic GPS core, master timing solutions—like the Safran NetClock —emulate the precise serial signatures defined by ICD-GPS-153C. This workflow regularly utilizes three fundamental messages: Message ID / Type Common Broadcast Rate Primary Purpose and Payload Characteristics 1 Hz (Once per second)
Primarily used to interface GPS receivers with battle command systems, tactical radios (like Link 16), and navigation systems. Emulation & Testing:
By enforcing a strict standard for RS-232 and RS-422 communications, the defense sector ensures that disparate elements—such as handheld navigation systems, vehicular display arrays, automated artillery positioning units, and tactical radios—interoperate natively without custom engineering work. Devices like BAE Systems' NavGuide M-Code GPS Receiver or legacy DAGR units maintain compliance with this interface spec to seamlessly retrofit existing installations. 3. High-Fidelity Time and Frequency Discipline