Performance analysis of a narrow correlator spacing receiver for precise static GPS positioning

The performance of narrow correlator spacing C/A code GPS receiver technology was assessed for static GPS surveying using 10-channel, single frequency GPSCard receivers. A series of surveys was conducted in the Eastern United States in December 1992 in support of this assessment. Baselines of 0.5 to 320 km were observed over several days to analyse repeatability and agreement with reference coordinates. The carrier phase measurements were post-processed using double and triple difference approaches. Precise orbits were used to isolate the atmospheric and receiver error sources. The effect of multipath on carrier phase measurements is demonstrated. In order to determine the effect of the ionosphere on long baseline (>200 km) solutions, the ionospheric effect was estimated using a single frequency code/carrier phase divergence approach. This method is particularly well suited in this case in view of the high C/A code accuracy of the GPSCard. The effect of the ionosphere on the baselines was found to reach several ppm. The repeatability of the baselines varies between 1.2 and 3.0 ppm. The agreement of the reference coordinates with the L1 baseline solutions is 3.7 ppm while that with the ionospherically corrected long baseline solutions is 1.1 ppm