%0 Journal Article %T GPS Satellite Range and Relative Velocity Computation %A Owis Ashraf H. %A Mohammed Hani M. %A Dwidar Hany %A Mortari Daniele %J Theory and Applications of Mathematics & Computer Science %D 2012 %I Aurel Vlaicu University Editing House %X In this work the estimation of a Global Positioning System satellite orbit is considered. The range and relative velocity of the satellite is computed in the observer¡¯s local reference frame (topocentric system of coordinates) by including the Earth gravitational perturbations (up to J3 term) and the solar radiation pressure. Gauss perturbation equations are used to obtain the orbital elements as a function of time, from which the position vector is derived. %K GPS Satellite %K Gauss Equations %K Solar Radiation Pressure %K Range %U http://www.uav.ro/applications/se/journal/index.php/TAMCS/article/view/54/37