Comparison of approaches to zenith tropospheric delay determination based on data of atmosphere radio sounding and GNSS observation
Currently, Global Navigation Satellite Systems (GNSS) are increasingly used in atmospheric monitoring tasks. To determine tropospheric delays, two approaches are most often used: the calculation of atmospheric radio sounding data and the processing of GNSS observations. GNSS processing is, generally, based on two methods, namely precise point positioning (PPP) and double-differencing (DD). PPP is a potent data analysis instrument sensitive to a variety of parameters.