Algorithms for Pseudorange and Time Determination in a Satellite Based Navigation Experiment With a Rail-Bound Vehicle

Abstract

In the satellite based navigation experiment with a rail-bound vehicle - SATNAB a GPS receiver, which receives only one GPS SA-free signal is used and is connected to an external Rubidium clock, which can be sychronized to GPS-time before the measurements. The SA-free GPS together with SATNAB specific receiver determine the sperical functions at any time as the rail-bound vehicle travels. The function, i.e. the space curve, of the rail track can be gotten from the GIS (Geoinformation System) database. The cross points of the spherical functions and the space curve of the rail track at any time are the positions of the vehicle. In this paper, algorithms for the determination of corrected pseudorange and time are discussed, and the first experiment results with the Novatel Millenium GPS receiver and the TEMEX 10MHz Rubidium Clock are presented.