Patent ID: 7256730
Filing Date: 2007-08-14
Classification: G01S

Abstract:
1. Method for real-time navigation using three-carrier radio signals of first, second and third different frequencies that increase in value from said first to said third carrier frequency, to determine the position of a rover, said radio signals being transmitted by a given number of transmitters installed aboard satellites orbiting around the Earth and in view of said rover, said signals being received by a receiver associated with said rover and a receiver associated with at least one ground station among a plurality of fixed ground stations called reference stations, said radio signals passing through an ionospheric layer of the atmosphere surrounding said earth and experiencing disturbances that generate phase ambiguities in said carriers, the method comprising the steps of: determining, in said rover, an extra-wide lane ambiguity of the phase differences between third and second carriers, from a combination of pseudoranges using a single code value; estimating, in said rover, a wide lane ambiguity of the phase differences between first and second carriers, from said extra-wide lane ambiguity; determining, in said rover, ambiguity resolution of one of said carrier frequencies from said wide lane ambiguity; and applying real-time ionospheric corrections during the resolving step, said ionospheric collections being based on a continuously updated real-time ionospheric model of said ionspheric layer.