Performance Analysis of Web-Based Relative and Precise Point Positioning Techniques With Different Satellite Visibility Conditions

Abstract

The Global Navigation Satellite System (GNSS) is used for precise positioning applications, such as surveying and geodesy. The aim of the present work is to evaluate the effectiveness of web-based relative positioning (RP) and precise point positioning (PPP) GNSS post-processing services using measurements of different satellite visibility obstacles. Within this framework, static GNSS observations were conducted at three control benchmarks selected taking the impact of natural and human-made obstacles on satellite signals into consideration. 3 hours of static GNSS observations in Istanbul, Turkey were repeatedly obtained from three control BMs over six days and were evaluated through two RP (AUSPOS, OPUS) and three PPP (CSRS-PPP, Magic-PPP, GAPS-PPP) web-based GNSS post-processing services. The 6-day average of the three control benchmark coordinates computed using the Bernese GPS software v5.0, and were accepted as true results. They were compared to the local coordinates acquired through the RP and PPP web-based GNSS post-processing services. The different satellite visibility conditions were found to have significant effects on the GNSS point positioning solutions. We also found that web-based GNSS post-processing services provide easy and effective solutions for geodetic positioning applications.

Automação do Processo de Mudança de Referencial Geodésico e Atualização de Coordenadas no Posicionamento de Alta Precisão

“…Dentre os sistemas mais utilizados para realizar o PPP, são: o IBGE-PPP (Instituto Brasileiro de Geografia e Estatística -Posicionamento por Ponto Preciso), o GAPS (GNSS Analysis and Positioning Software), o APPS (Automatic Precise Positioning Service), o CSRS-PPP (Canadian Spatial Reference System -Precise Point Positioning), o RT_PPP on-line (Real Time -Precise Point Positioning), o RTX -PP (CenterPoint RTX Post-Processing) e o magicPPP (Precise Point Positioning Service). Para efetuar o PR temse, dentre outros, o OPUS (On-line Positioning User Service), o SOPAC (Scripps Orbit and Permanent Array Center) e o AUSPOS (on-line GPS data processing) (CARVALHO et al, 2014;GUO, 2015;MARQUES et al, 2015;TARIQ;HADI;HAFEDH, 2017;MACIUK;SKORUPA, 2017;IBGE, 2017;OZULU;EROL;ALKAN, 2018;ALBAYRAK;ERDOĞAN;ERKAYA, 2020).…”

Accuracy Assessment of a Variety of GPS Data Processing, Online Services and Software

“…The majority of the users of GPS data employ it effectively in different engineering and geodetic projects as an alternate solution to traditional surveying methods [1]. In order to achieve a high degree of precision in terms of location, the use of differential positioning techniques is required in field measurements and in the processing of GPS data using License postprocessing or Commercial software employed by GPS experts [2]. This software required user training and experience [1].…”

“…One of those methods is the online web-based GNSS analysis tool, that calculates user coordinates to a precision of centimeters [11] is the Online Positioning User Service (OPUS) which is controlled by the National Geodetic Survey (NGS) [12], and AUSPOS which is the online static GPS position program of Geoscience Australia [13]. A computer with Internet access and a web browser are the only condition to use these programs, which are usually offered free of charge and for unlimited use [2].…”