navigation message

Data that is modulated onto the signal from a navigation satellite. The navigation message contains ephemeris and clock data for that particular satellite, plus other data required by a receiver to compute position velocity and time and almanac data for all GPS satellites.

The navigation message is transmitted at 50 bits per second in 1500-bit frames, each requiring 30 seconds to transmit. A complete set of data to include all almanacs, timing information, ionospheric information and other data requires 12 1/2 minutes to transmit.

See also NAVDATA.