Comparisons of Ground-Based and Building-Based CORS: A Case Study in the Region of Puerto Rico and the Virgin Islands

摘要

This study investigated long-term observations from three pairs of closely spaced, continuously operating reference stations (CORS): STVI and VITH (2008-2014, 0.6 km apart), BYSP and PRHL (2008-2014, 3.2 km apart), and CRO1 and VIKH (1995-2014, 23 km apart), in the region of Puerto Rico and Virgin Islands. The Global Positioning System (GPS) antennas of STVI, BYSP, and CRO1 are mounted on ground-based monuments. The GPS antennas of VITH, PRHL, and VIKH are mounted on building-based monuments. This study indicated that there is no considerable difference between building-based and ground-based CORS with regard to the precision of daily positions and the reliability of long-term site velocities. The amplitude of thermal movements associated with daily temperature changes and the wind drift associated with air pressure change from a 2-story concrete building fell below the detectable levels of the present high-precision GPS technique determined by Precise Point Positioning (PPP) processing. Further analysis indicated that (1) building-based CORS can retain more complete GPS observations and provide a more stable multipath environment, and (2) the large and heavy mass of the building and its foundation can decrease the amplitude of seasonal signals and filter certain short-period motions. As a result, the building-based CORS have the potential to perform better than the ground-based CORS as long as their monuments are firmly fixed on 1-story or 2-story concrete buildings and the buildings themselves are stable.