caa a22 4500 60616250X CHVBK 20210128100639.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s10291-014-0413-5 doi (NATIONALLICENCE)springer-10.1007/s10291-014-0413-5 Guo Qiuying School of Civil Engineering, Shandong Jianzhu University, Jinan, China aut Precision comparison and analysis of four online free PPP services in static positioning and tropospheric delay estimation [Elektronische Daten] [Qiuying Guo] Observation data sets from three different periods and 23 International GNSS Service (IGS) stations spread over the world were processed in static mode using four online free precise point positioning (PPP) services: Automatic Precise Positioning Service (APPS), GPS Analysis and Positioning Software, Canadian Spatial Reference System precise point positioning service, and Magic-PPP. The estimated positions of the 23 IGS stations were compared with the published values. The estimated zenith tropospheric delays (ZTDs) at these stations were compared with the corresponding IGS troposphere products published on the IGS Web site. Furthermore, in order to analyze PPP precision for short observation periods, GPS observation data sets with a sampling rate of 1s collected by one CORS station were also processed by the four online PPP services. Calculation shows that the precision of daily solutions for north and east (N/E) components estimated by the four online PPP services can reach millimeter level, the precision of ellipsoid elevation (H) can reach 1-2cm, and precision of ZTDs estimation results is approximately 1-2cm. Compared with the corresponding values published on the IGS Web site, the precision of ZTDs estimated by APPS is higher than those estimated by the other three PPP online services; the differences between ZTDs by APPS and IGS values are mostly within ±1cm. For PPP with short observation periods, the precision of N/E components within 2, 1, and 0.5h observation periods can reach about 2-3, 2-7, and 3-8cm, respectively, while the precision of H components is about 3-5, 5-12, and 10-18cm, respectively. Springer-Verlag Berlin Heidelberg, 2014 GNSS nationallicence Online PPP nationallicence Static positioning nationallicence Zenith tropospheric delays nationallicence Precision analysis nationallicence GPS Solutions Springer Berlin Heidelberg 19/4(2015-10-01), 537-544 1080-5370 19:4<537 2015 19 10291 https://doi.org/10.1007/s10291-014-0413-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10291-014-0413-5 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Guo Qiuying School of Civil Engineering, Shandong Jianzhu University, Jinan, China aut NATIONALLICENCE 773 0- GPS Solutions Springer Berlin Heidelberg 19/4(2015-10-01), 537-544 1080-5370 19:4<537 2015 19 10291