Differential GPS dynamic location experiments at sea

Differential GPS on board naval vessels has been tested in severe multipath archipelago environment against a commercial laser tracker system. The average location difference was 3 meters and two periodic error components were found. Their tune constants were 1.8 and 28 seconds and the peak amplitudes 1.5 and 1.1 meters, respectively. In addition to these, a clear dependency of location error standard deviation figures on the GPS antenna mounting distance from the sea level was observed.