The Operational Advisory (also known as a GPS Status Message) provides a summary of the status of the satellite constellation. The advisory is is divided into four parts: Header, Section One (1), Section Two (2), and Section Three (3). You may also visit our GPS Acronyms and Abbreviations page.
- The header includes the title, subject, and the date. The date is represented in a format that includes the
- two digit day (DD), the first three characters of the month (MMM), and the four digit year. Also included is the Julian day of the year.
- This lists operational satellites by PRN number, assigned plane, and atomic clock in use.
- Block I - This generation of satellites is no longer used.
- Block II - This is the current generation of operational satellites.
- PRNs - Pseudo Random Noise code is the unique identifying sequence code that each satellite produces.
- Slot - This indicates what plane and slot the satellite is occupying. The "plane" is the satellite's orbit, and the "slot" is the position in the plane.
- CS & RB= Cesium and Rubidium are the atomic clocks used on the satellites, as noted for each satellite.
- Section Two
- This contains a summary of current and recent advisories, forecasts, and general text messages. It is organized into scheduled Notice Advisory to Navstar Users (NANU) messages, Operations Advisories, and general text messages.
- You may also read the various NANU ab/gps-acronyms-abbreviations breviations and descriptions or search for individual NANUs in the current year, or view our NANU Archives.
- Section Three
- This identifies the points of contact for additional technical and support information. You may contact the Navigation Information Service for further information and questions.