A Kalman filter for an integrated Doppler/GPS navigation system

A Kalman filter has been designed to integrate a Doppler radar navigation system with a GPS (global positioning system) system. The filter uses eight states for flights over land, and ten over water. Simulation data shows navigation errors of 1 m or less on each axis under good operating conditions. The performance is equivalent in position error to the standard standalone GPS filter in straight and level flight, and superior in maneuvering flight under dynamic conditions. The filter implementation was also designed to provide additional improvement in the performance of a Doppler navigation system. The results demonstrate that this capability was achieved.<<ETX>>