: Because the protocol is well-defined, it is also used to emulate a SAASM GPS for testing and simulation. NetClock and VersaSync systems can generate these messages to emulate the time and 1PPS transfer behavior of a SINCGARS radio interface. This allows developers to test their systems without needing a live, classified SAASM GPS receiver.
Ground-Based GPS Receiver Application Modules (GB-GRAM) utilize GSSIP to output navigation data to platform computers, often supplying two channels of GSSIP and one channel of NMEA-0183.
The protocol is a critical military standard interface specification governing data communication between Department of Defense (DoD) Standard GPS Radio Receivers and external equipment. While commercial GPS units rely on NMEA 0183, ICD-GPS-153 is tailored for the stringent security and accuracy needs of military platforms, often used with Selective Availability Anti-Spoofing Module (SAASM) GPS receivers.
The ICD-GPS-153 protocol defines several message types, each with a unique identifier. Some of the most common message types include: icd-gps-153 protocol
The protocol defines numerous message types categorized by functional IDs. A common application for the modern iteration, , involves emulating secure hardware connections for older radios or host architectures.
To obtain the complete specification (e.g., ICD-GPS-153C), developers often must submit a GPS Technical Library Document Request through the U.S. Coast Guard Navigation Center . ICD-GPS-153 vs. NMEA-0183 ICD-GPS-153 Primary Use Military/Industrial Timing & Emulation Consumer/Marine Navigation Data Format Binary/Structured ASCII (GSSIP) ASCII "Sentences" Common Messages Time Transfer, Current Status $GPGGA, $GPRMC, $GPVTG Accessibility Controlled/Restricted Fully Public Interface Control Documents - GPS.gov
Supplies auxiliary operational parameters and background maintenance frames to the host. : Because the protocol is well-defined, it is
This article provides a deep dive into the purpose, structure, and applications of ICD-GPS-153, focusing on its role in military PNT (Positioning, Navigation, and Timing) solutions. 1. What is ICD-GPS-153 (GSSIP)?
ICD-GPS-153 is implemented across a wide array of mission-critical hardware:
: A distinct byte pattern indicating the start of a new message block. The ICD-GPS-153 protocol defines several message types, each
+---------------------------+ RF Signal +---------------------------+ | GPS Satellite Constellation | --------------> | Military GPS Receiver | +---------------------------+ | (SAASM / MGUE / M-Code) | +---------------------------+ | | ICD-GPS-153 Protocol | (GSSIP Serial Interface) v +---------------------------+ | Host Mission System / | | Tactical Weapon Terminal | +---------------------------+
is a technical specification that defines the serial interface protocol (RS-232/RS-422) used by DoD standard GPS User Equipment (UE). It allows external devices to communicate with receivers like the (Precision Lightweight GPS Receiver) and
When we think of GPS, we typically imagine the blue dot on a smartphone map. That experience relies on the (Coarse/Acquisition) code, a civilian signal documented in the public IS-GPS-200 standard. However, beneath this commercial veneer lies a more powerful, more resilient, and highly classified ecosystem known as the GPS Precision Service (P(Y) Code) .
One of its primary uses is to emulate a SINCGARS (Single Channel Ground and Airborne Radio System) interface connection for SAASM-capable GPS units.