Abstract
In this paper,we propose a method in which GPS satellite orbits are predicted by using previously recorded navigation data to improve TTFF (Time To First Fix) of GPS receivers. We calculated GPS satellite orbits during 72 hours and compared the results with precise orbits provided by IGS. We also evaluated the accuracy of the predicted orbit. For the test,the simulation used JGM-3 up to 8th order for the earth potential and GSPM.04b for the solar radiation pressure model. The result shows that the user range error is below 90 meters and proves the effectiveness of the proposed method.
