Patent ID: 6831596
Filing Date: 2004-12-14
Classification: G01S

Abstract:
A GPS calibration system comprising the combination of:a GPS digital radio receiver having a sampling algorithm operating at a receiver sampling frequency and a range computation algorithm embodied therein; a GPS satellite emitting digitally coded geographic location identification signals receivable by said GPS digital radio receiver; a Wide Area Augmentation System station broadcasting GPS error correcting data to a geographic region inclusive of said GPS digital radio receiver; said Wide Area Augmentation System station generating a broadcast signal inclusive of a known precise frequency signal component controlled by a Wide Area Augmentation System clock of enhanced timing accuracy with respect to said GPS digital radio receiver sampling frequency; frequency comparison apparatus in said GPS digital radio receiver and generating a difference signal responsive to timing difference errors between said GPS digital radio receiver sampling frequency and a correct value of said sampling frequency determined from said Wide Area Augmentation System known precise frequency signal component; said frequency comparison apparatus including both a coherent mathematical integration function and an incoherent mathematical integration function; and range computation algorithm correction apparatus located in said GPS digital radio receiver and responsive to said receiver sampling frequency and said difference signal.