The ICD-GPS-153 protocol, also known as the Interface Control Document for GPS-153, is a technical standard that defines the communication protocol between a GPS receiver and a host device. This protocol is widely used in various applications, including navigation systems, tracking devices, and other GPS-enabled equipment.
In short, ICD-GPS-153 specifies the electrical and protocol interface between a (e.g., a missile, aircraft, or jammer-resistant timing unit) and a GPS receiver employing SAASM (Selective Availability Anti-Spoofing Module).
The ICD-GPS-153 protocol message structure consists of:
It defines exactly how the "Buffer Box," "Time Transfer," and "Current Status" messages are structured.
In the high-stakes world of defense and precision navigation, communication is everything. This is the story of ICD-GPS-153 icd-gps-153 protocol
Detailed signal-to-noise ratios and status for all satellites in view.
: The protocol operates hand-in-hand with the GPS Standard Serial Interface Protocol (GSSIP) . This framework defines how packetized ASCII or binary streams are wrapped, validated, and pushed out across communications ports.
The industry needed a standard. Enter (Interface Control Document).
(Defense Technical Information Center) may hold further documentation on GPS security and interface standards. If you'd like, I can: Explain the differences between SAASM and M-Code. The ICD-GPS-153 protocol, also known as the Interface
It is crucial to understand that ICD-GPS-153 is a typical civilian standard like NMEA 0183, which is openly documented and widely used in commercial marine and automotive applications. Instead, it is a controlled interface designed for secure military applications, with versions like ICD-GPS-153C used for specific functions like time transfer.
The ICD-GPS-153 protocol was developed by the U.S. Department of Defense (DoD) and the National Aeronautics and Space Administration (NASA) in the 1990s. At that time, GPS technology was still in its early stages, and there was a need for a standardized communication protocol to facilitate the integration of GPS receivers with various host devices. The ICD-GPS-153 protocol was designed to meet this need and has since become a widely adopted standard in the GPS industry.
: It acts as the software data bridge for specialized security hardware like Selective Availability Anti-Spoofing Modules (SAASM) and modernized M-Code receivers.
Within the Department of Defense (DoD) ecosystem, an acts as the definitive design blueprint for resolving compatibility between disparate physical systems. The ICD-GPS-153 protocol defines the software and register-level messaging rules for command, control, and data readout between a User Equipment (UE) GPS receiver —such as the legacy Defense Advanced GPS Receiver (DAGR) or a modern Ground-Based GPS Receiver Application Module (GB-GRAM) —and its host vehicle, aircraft, tactical radio, or time server. The ICD-GPS-153 protocol message structure consists of: It
It supports the emulation of a SAASM GPS receiver, allowing simulation systems or non-GPS equipment (like radios) to "talk" to a GPS receiver.
Developing a receiver to ICD-GPS-153 is not simply an engineering challenge; it is a legal barricade.
When these formats are deployed for emulation purposes to avoid using restricted hardware components, the position and velocity matrices are intentionally zeroed out. This step safely ensures that no unclassified configuration spills controlled tactical data. Security, Distribution, and Compliance GSSIP Message Format - Safran - Navigation & Timing