Portable System for Extending GPS Coverage
Keywords: Motorola
Applicant: Motorola, Inc., USAPatent number: US6,091,359Publication date: 18 July 2000Title: Portable Dead Reckoning System for Extending GPS Coverage
A method for extending GPS coverage in an automotive environment without requiring direct interfaces to the vehicle's sensors in a unique and cost effective way is presented. The invention removes all required vehicle interfaces (except power), to produce a virtually portable navigation system with no installation requirements beyond that of the GPS receiver itself. It also removes the necessary customisation of the navigation system to each particular vehicle. Fundamentally, the position of a vehicle is obtained by GPS receiver data augmented with a low cost gyro, whereby the gyro accurately tracks the heading changes of the vehicle in the absence of sufficient GPS information. The GPS receiver also includes an innovative algorithm for deriving speed information from Doppler measurements from just one or two GPS satellites.
