Comparative Analysis of Online Static GNSS Postprocessing Services

Abstract

Several precise point positioning or relative positioning services are available online for postprocessing static global navigation satellite system (GNSS) data collected on a single mark. The accuracy of five services (OPUS-S, AUSPOS, CSRS-PPP, GAPS, TrimbleRTX) were compared by processing the same 49 static GNSS files of varying session duration (from 2 to 1 h) on six passive marks in minimal or moderate multipathing environments. First, only Global Positioning System (GPS) observables at a 3-s logging rate were tested using each service. Then, the effects of including observables from Russia’s GNSS (i.e., GLONASS) were investigated using TrimbleRTX and CSRS-PPP, and the accuracy of processing data at faster logging rates were evaluated using TrimbleRTX. The results from each service were differenced with coordinates derived from a high-accuracy campaign-style static GNSS survey. Increasing the logging rate from 3 to 1 s did not significantly reduce the root-mean-square error (RMS) of the differences. However, adding GLONASS observables significantly reduced the horizontal RMS by an average of 17.1% and 36.7% at sites in minimal and moderate multipathing environments, respectively.