Analytical study of the use of precise geodetic products on the accuracy of geodesic reference networks to monitor displacements measured GNSS

Abstract

The accurate processing of displacement monitoring networks that uses the Global Navigation Satellite System (GNSS) is deeply associated with the strict measurement conditions first, and then with the constraints of post-processing second. This type of processing needs precise geodetic products, the most important of which are orbital corrections that International Navigation Systems Service (IGS) provides to define whether they are used as corrections for standard navigation messages or as a substitute for them.

The research aims to study the effect of using precise orbital products from IGS on position accuracy in displacement monitoring networks analysis in two criteria. The first uses accurate orbit files (*.sp3), and the second integrates standard navigational message files (*.yyp) in two levels: level one processes locally measured stations, and the other processes local stations with the support of IGS stations surrounding the study area.  

The displacement monitoring network analysis of the faculty of civil engineering in Tishreen University which is measured by the GNSS classical static method showed that the accuracy of the networks consisting of local stations using integration of the accurate navigation message from IGS and the standard navigation message reached (±3 mm) horizontally and (±5 mm) vertically in comparison to (±5 mm) horizontally and (±9mm) vertically when using the accurate navigation message from the IGS alone. The value reached (±3 mm) horizontally and (±5 mm) vertically when IGS stations are integrated. This confirms the necessity of using the navigation message (*.yyp) in conjunction with (*.sp3) as an essential condition to improve the geodetic networks accuracy.