Global Navigation Satellite System (GNSS) IGS Summary of Orbit and Clock Comparisons of Analysis Center (AC) and Combination Real-Time Solutions with IGS Rapid Solutions from NASA CDDIS

The real-time observation data from a global permanent network of ground-based receivers are transmitted from the CDDIS in 1 to multi-second intervals in raw receiver or RTCM (Radio Technical Commission for Maritime Services) format. These real-time data are utilized to generate near real-time product streams. The real-time products consist of GNSS satellite orbit and clock corrections to the broadcast ephemeris.

These correction streams are formatted according to the RTCM SSR standard for State Space Representation and are broadcast using the NTRIP protocol. These real-time data are utilized to generate near real-time product streams. The real-time products consist of GNSS satellite orbit and clock corrections to the broadcast ephemeris.

These correction streams are formatted according to the RTCM SSR standard for State Space Representation and are broadcast using the NTRIP protocol. The product streams are combination solutions generated by processing individual Real Time solutions from participating IGS Real-time Analysis Centers. The effect of combining the different AC solutions is a more reliable and stable performance than that of any single AC's product.

The solution summary files consist of orbit and clock comparisons of all the AC and combination streams against IGS rapid solution. These products have been provided in support of the IGS RTS (previously Real-Time Pilot Project) since February 2009, prior to the availability of real-time product streams. This summary of the combination product is a daily report available approximately one to three days after the end of the previous UTC day.