Improvement of GPS relative positioning accuracy by using SNR

Interference and multipath are the main error sources of Global Positioning System (GPS) measurement in engineering surveying. This paper describes an algorithm that mitigates specular multipath as well as interference in GPS differential carrier phase measurement by using signal-to-noise ratio (SNR ). The focus is on multipath because it accounts for most of the total erro r budget in differential carrier phase measurement. The algorithm is demons trated on static platforms in severe multipath environments. The accuracy i s tested with predefined displacements on an X-Y-Z stage, and the experimen tal results are compared to sidereal day-to-day repeatability. The data set s used for investigation are six-epoch measurements, and the accuracy of th e six-epoch solution is shown.