Performance of web-based GNSS processing software

Web-based GNSS processing software has been developed as an alternative to classical processing methods, which have recently attracted the attention of researchers and have been the subject of many scientific studies. Web-based GNSS software allows users to obtain coordinates with cm/dm accuracy. At the same time, many advantages such as the fact that these software are generally free of charge, can be accessed anywhere with an internet browser and connection, do not require users to have a high level of GNSS knowledge, and have a very simple user interface make these software preferred. In this study, the performance of web-based and open source GNSS software have been investigated. Five IGS stations (NOT1, SULP, ANK2, BOR1 and MIKL) at different latitudes/longitudes were selected for the study. Firstly, the effect of the Space Weather Condition indices which have a negative effect on GNSS measurements (Kp, Dst, F10.7, Bz (GSE, GSM)) was investigated. It was observed that all of the Space Weather conditions remained generally quiet during the selected date range. As a result, 24-hour RINEX data were divided into 6- and 12-hour segments using measurements at IGS stations and processed with web-based (CSRS-PPP, MagicGNSS, APPS, Trimble-RTX, IBGE-PPP, IGN-PPP, AUSPOS, OPUS) and open source (raPPPid, PPPH) processing software. In the evaluations, the coordinates obtained were compared with reference values for accuracy and the results were interpreted. Comparing the evaluations in all hourly periods, it was observed that the web-based CSRS-PPP and APPS software and the open source raPPPid software gave more successful results than other software. As a result, it was seen that web-based GNSS processing software is easier to use than open source software, and the calculated coordinates show better approximation to the reference coordinates when the space weather conditions remain calm and the selected stations are taken into consideration.