Influence of satellite ascending and descending orbits on GNSS-IR sea level retrieval
Aiming at the problem that in the global navigation satellite system-interferometric reflectometry (GNSS-IR) sea level retrieval based on signal-to-noise ratio (SNR) data,the retrieval accuracy is affected by many factors,among which the satellite orbit change directly affects the height variation error,however,continuous tracking of satellite signals may lead to different SNR data quality of ascending and descending orbits at low satellite elevation,the paper studied the influence of satellite orbit change on GNSS-IR sea level retrieval:the GNSS-IR principle was given,and the influence of satellite lifting orbit was analyzed;then the data collected from SC02 and AT01 stations were tested.Experimental result showed that satellite orbit change would directly affect the SNR oscillation effect,and the retrieval results of descending orbit would be better than that of ascending orbit;meanwhile,due to different environments and equipment,the influence of ascending and descending orbits would be also different;moreover,the retrieval accuracy of descending data could be improved by more than 5 cm compared to ascending orbit data for SC02 station,and more than 3 cm for AT01 station.Therefore,during processing GNSS-IR sea level multi-frequency and multi-mode retrieval data,the influence of satellite ascending and descending orbits cannot be ignored
global navigation satellite system-interferometric reflectometry (GNSS-IR)signal-to-noise ratio (SNR)sea levelascending orbitdescending orbit