A Comparison of Accuracy Using a GPS and a Low-Cost DGPS

摘要

After the cancellation of selective availability in May 2000, the accuracy of plain uncorrected global positioning systems (GPSs) is significantly increased. Currently, the main cause of error in plain GPS receivers is imperfect compensation of the ionospheric error. Tests performed in New Zealand show that even a simple code range differential GPS (DGPS) provides significant improvement in accuracy over a plain GPS and can be implemented using low-cost off-the-shelf equipment. A simple statistical model of positioning error estimation is developed and applied on data obtained by measurements in order to verify the findings. The method, which needs only position information without satellite constellation, provides sufficient accuracy when simultaneously gathered plain GPS and DGPS data are compared.