DISTANCE-DEPENDENT ACCURACY OF GNSS BASELINE MEASUREMENTS A COMPARATIVE STUDY OF GPS, GLONASS, AND INTEGRATED GPS/GLONASS SYSTEMS

Abstract

This study examines the accuracy of coordinate and baseline determinations using various satellite positioning methods—GPS, GLONASS, and integrated GPS/GLONASS—across increasing distances from a base station. Conducted along the Mansoura–Damietta Road in northern Egypt. The research focuses on static GNSS receiver operations under varying Position Dilution of Precision (PDOP) levels. Field data were collected using both satellite and traditional surveying techniques. Baseline measurements were taken between unknown stations using a total station, providing reference values for comparison. GNSS data from the base and rover stations were processed using Justin software. The results prove that the combined GPS/GLONASS system provides significantly higher accuracy in both coordinate and baseline measurements compared to either system used independently. The study found that baseline length measurements maintained an accuracy of 2–8 cm, with a correlation coefficient of 96%, even at distances up to 10 km from the base station under favorable weather conditions.