Effective Use of the ConnDOT GPS Base Station

摘要

This report presents the findings of an investigation of factors affecting GPS position accuracy using the ConnDOT base station. An empirical study was performed to evaluate the accuracy of carrier-phase Global Positioning System (GPS) as a function of: number of control points used, distance to control, observation time and number of frequencies observed. To facilitate the study, a 19-station control network was developed in Southeastern Connecticut and surveyed to High Accuracy Reference Network (HARN) standards using dual frequency, carrier-phase GPS. The network was controlled using existing HARN stations in Connecticut, Massachusetts and Rhode Island. GPS observations were subsequently taken independently and processed in various ways to measure the effect of the control variables on the positional accuracy obtained. Results showed the ability of carrier-phase GPS to deliver high accuracy results both vertically and horizontally in reasonable times, especially when using two GPS frequencies and having three base stations surrounding the study area.