GPS Pseudo Range Correction by the Number of Reflections and Incident Angle Estimations

In GPS, the pseudo ranges between GPS satellites and GPS receivers, calculated from the propagation times, are used for positioning calculations. However, when reflected signals are received, their pseudo ranges longer than the original linear distances are observed. They would degrade positioning accuracy especially in high-rise building environments. In order to solve this problem, pseudo range correction method has been proposed. Although it needs to estimate the number of reflections and incident angle of the received GPS signal, the estimation accuracies by the conventional estimation are not enough to improve GPS calculated distance errors. In this paper, we propose new estimation models that estimate the number of reflections and incident angle by using the pseudo ranges before the correction in addition to the conventional received GPS signal power. It is clarified that the pseudo range correction method applied by the proposed estimations more improves GPS calculated distance errors than that with the conventional estimations.