ASSESSMENT OF 3D POSITIONAL ACCURACY OF GEODETIC OBSERVATIONS FROM SINGLE CORS

Abstract

Geodetic observations for both vertical and horizontal control networks cannot be compromised for any reason in accuracy and precision in the field of geomatics. Due to the error-prone nature of survey measurements, standards are established to allow for comparing the obtained results with a set of guidelines, regulations, or pre-determined specifications. The University of Benin’s Ugbowo Campus in Nigeria does not have enough control points, which informs this study. The densification of more reliable control points using the most recent technology is necessary. Before the observations, control network design, excavation, casting, and monumentation of first-order compliance beacons had been completed. Eight GNSS receivers were connected to the CORS_Geosystems multi-link access point and simultaneously deployed for observations. The stages involve the adjustment of observed data, the presentation of adjusted results, and the determination of horizontal and vertical accuracies. The result of horizontal accuracy showed that the RAPH_GNSS_08 station had the highest horizontal accuracy standard ratio of 1:432,193, while the Raph_GNSS_04 station had the lowest, 1:133,271. The highest vertical accuracy standard was 4.0mm, achieved between Cors_Geo and RAPH_GNSS_09, while the lowest, which was 3.1mm, was observed between Cors_Geo and RAPH_GNSS_08. High-precision engineering projects in the research area will benefit from the established first-order controls in terms of execution, monitoring, and maintenance. The Surveyors Council of Nigeria (SURCON) has recommended GNSS as one of the methods for achieving geodetic control densification in Nigeria.