Patent ID: 6166684
Filing Date: 2000-12-26
Classification: B64G,G01S

Abstract:
An artificial satellite navigation system comprising:a first global positioning system (GPS) receiver for receiving GPS signals;a communication unit for communicating with a remote satellite and including a second GPS receiver;a local satellite absolute navigation unit for receiving a signal from said first GPS receiver, and estimating position and velocity of a local satellite and bias and drift caused by a clock in said first GPS receiver;a remote satellite absolute navigation unit for receiving a signal from said communication unit, and estimating the position and velocity of a remote satellite and bias and drift caused by a clock in said second GPS receiver;a difference calculation unit for calculating differences in position and velocity from the output of said local satellite absolute navigation unit and the output of said remote satellite absolute navigation unit; anda relative navigation unit for estimating the relative position and velocity of the local satellite with respect to the remote satellite, wherein said difference calculation unit outputs the differences expressed in a system of coordinates defined with reference to the remote satellite and said relative navigation unit relatively navigates the local satellite according to the output of said difference calculation unit.