RADIO NAVIGATION SYSTEM USING OUT-OF-BAND PSEUDOLITES

摘要

A system of stationary pseudolite navigation transmitters for broadcasting a GPS-like signal at a frequency F1, a non-GPS carrier frequency, is provided in the environment of GPS spread spectrum navigation signals at a radio frequency L1. A plurality of pseudolite stations (PL) broadcast a plurality of spread spectrum pseudolite navigation signals at a radio frequency F1 which are at a different frequency than the frequency L1. According to the invention, at least one reference station (REF) is provided for receiving the GPS navigation and the pseudolite navigation signals and deriving navigation correction data (Differential GPS, kinematic observations data) signals. At least one of the pseudolite stations serves as a master station (PL1) in association with each reference station. A communication link provides differential GPS and observation data signals from each reference receiver to its master pseudolite station(s) which modulate(s) the reference station observations and integrity data for broadcasting to a plurality of mobile receivers (NRX) which receive the pseudolite and GPS navigation signals including the navigation correction signals from the master pseudolite stations and produce accurate navigation information therefrom in the presence or absence of useful GPS navigation signals.