RTCA SC-159 Wide Area Integrity Broadcast/Wide Area Differential GPS status

The Wide Area Integrity Broadcast (WIB) (formerly the GPS Integrity Channel-GIC) will use a network of ground stations at known locations to determine the status of every GPS satellite in view. It will then broadcast satellite health to GPS users in real time from a geostationary satellite (GS), thus providing system integrity. This broadcast will also include error estimates for the same GPS satellites that are valid over a specified region, which may include one or more countries or continents. These estimates, if accurate enough, can be used as differential corrections. This concept is called Wide Area Differential GPS (WDGPS). In addition, the broadcast signal will be modulated with a pseudo random noise (PRN) code that is synchronized with GPS time. Thus, it can also be used for ranging to augment the GPS system, thus improving system availability and continuity.<>