Inter-satellite Pseudorange Difference Indoor Positioning Using Simulator Pseudolites

The positioning system combining pseudolite technology and the navigation signal simulator is proposed to solve the problem that the indoor satellite navigation signal is lost. We adopted the simulator to generate the virtual orbit pseudolite and broadcast satellite signals through four indoor antennas. The simulator pseudolite is designed with Inclined Geosynchronous Orbit (IGSO) satellite to reduce the folding error caused by the fact that the simulator pseudolite, indoor antenna and receiver are not in a straight line. Furthermore, the observation equation is constructed using the position of the indoor transmitting antenna and the arrival receiver pseudo-range difference as the reference, which time difference of arrival (TDOA) localization algorithm is employed to further eliminate the fold line error. Experiments show that the position results of about 93.6% cases are better than 1m.