Patent ID: 7117417

Claim:
A method for generating GPS satellite clock corrections, comprising: obtaining dual-frequency pseudorange code measurements and carrier-phase measurements from a plurality of satellites; for each of the plurality of satellites, forming a smoothed refraction-corrected code measurement based on the dual-frequency pseudorange code measurements and carrier-phase measurements from the satellite, wherein the forming is performed for each of a series of measurement epochs preceding and including a current measurement epoch, wherein forming the smoothed refraction-corrected code measurement at the current measurement epoch includes smoothing refraction-corrected code measurements with refraction-corrected carrier phase measurements, and wherein smoothing the refraction-corrected code measurement includes forming projections of the smoothed refraction-corrected code measurements using changes in the carrier-phase measurements between two consecutive measurement epochs and computing an expanding average of differences between the projections and the refraction-corrected code measurements over a series of measurement epochs; and computing clock corrections for the plurality of satellites based on the smoothed refraction-corrected code measurements.