The usage of GPS (Global Positioning System) in various fields is growing. The best solution known for GPS outage problems in vehicle navigation systems is DR (dead reckoning). An inertial system based on distance and heading sensors backs up the GPS equipment by relaying information during periods without satellite visibility. Because the DR inertial system delivers relative positions and GPS absolute positions, it seems logical to combine the two to minimize the cumulative drift errors,mainly due to distance and heading sensor resolution.
For in-vehicle GPS receiver, there are problems in maintaining the operation performance even in unfavorable environments like an urban area and using antenna layout which does not hinder the vehicle design.
In the text,the solutions to these problems and a new type GPS receiving system which is equipped with Toyota Electro-Multivision(