Patent ID: 7471241
Filing Date: 2008-12-30
Classification: G01C,G01S

Abstract:
1. In a navigational system utilizing a plurality of satellites having time and orbit information, that transmit radio-frequency signals embedded with said time and orbit information, a method of obtaining a navigational solution, comprising the steps of: providing an incoming signal forward transformation system that is not satellite specific, wherein said incoming signal forward transformation system receives the radio-frequency signals from a plurality of the satellites and converts the radio-frequency signals received to a predetermined intermediate frequency, therein producing converted signals; providing a satellite specific processing system, wherein said satellite specific processing system obtains signals corresponding to different satellites contained within said plurality of satellites from said converted signals and generates a local reference code for said different satellites; obtaining a satellite signal channel transfer function; filtering said satellite signal channel transfer function to produce a filtered satellite signal channel transfer function; converting said filtered satellite signal channel transfer function to a time domain, yielding an estimated satellite signal channel impulse response, therein processing said converted signals and said reference code for each said different satellite to form a satellite signal channel impulse response estimate for each said different satellite; utilizing each said satellite signal channel impulse response estimate to extract navigation data, code time, carrier phase and frequency parameters from said radio-frequency signals; and utilizing said navigation data, said code time, said carrier phase and said frequency parameters from said plurality of satellites to produce a navigation solution.