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

Israa H Mohammed,Tariq N Ataiwe,Hisham Al Sharaa

doi:10.7494/geom.2021.15.4.5

Israa H Mohammed, Tariq N Ataiwe + Show 1 more

Open Access

https://doi.org/10.7494/geom.2021.15.4.5

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Abstract

The processing of GPS observations in precise positioning is complex and requires professional surveyors since it must be carried out after each static measurement. In GPS network adjustment, the obtaining of the correct coordinates of the determined point is possible after determining the components of GPS vectors and aligning the networks of these vectors, while PPP requires the availability of precise products for the reference satellites orbits and clock. For that reason, surveyors can take advantage of free online GPS data processing. In this paper, the authors compare the results obtained from different sources of free online GPS data processing (AUSPOS, OPUS, CenterPoint RTX, APPS, MagicGNSS, CSRS-PPP, GAPS, and SCOUT) in terms of their accuracy, availability, and operation. This is then compared with free GPS processing software (gLAB and RTKLIB), and finally with commercial software (TBC Trimble Business Center). The results show that online processing services are more accurate than offline processing software, which indicates the strength of their algorithms and processes. The CSRS-PPP online service had the best results. The difference between the relative solution of AUSPOS and OPUS, and CSRS-PPP is insignificant.

Highlights

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]
Various positioning methods are used in this research for different precise online applications, AUSPOS, Online Positioning User Service (OPUS), CenterPoint RTX, APPS, MagicGNSS, CSRSPPP, GAPS, and Scripps Coordinate Update Tool (SCOUT), the results are processed and analyzed
All the online processing method provides their coordinates in International Terrestrial Reference Frame ITRF 2014, and the final coordinates of the processing of the gLAB, RTKLIB, and TBC are in WGS84 (G1762)

Summary

Introduction

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]. During the last several years, some research centers, universities, and organizations have adopted new methods for GPS data analysis and processing in order to achieve high-precision GPS locations [4,5,6,7,8,9,10] 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]

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Results

Conclusion