System for accurate geospatial location and time transfer using radio transmissions without satellite signals

Abstract

A system for accurate geospatial location and time transfer using radio transmissions without satellite signals. A position and timing measurement system uses standard uncorrelated radio broadcast signals, each of which transmits on an assigned frequency from a known position defined in latitude and longitude, and each of which transmits a modulated or unmodulated carrier signal. A reference unit at known fixed position receives the said standard broadcast signals in the vicinity, samples the frequencies and content values of their signals and broadcasts the said measured frequency and content data nearly simultaneously with a time mark representing the time of said measurement and further broadcasts its position in latitude and longitude. A mobile unit at an unknown position to be determined receives the said standard broadcast signals in the vicinity and measures the time of arrival of their broadcast, recording the time of said measurement.