Frequency domain modeling of aided GPS for vehicle navigation systems

Position information P obtained from standard global positioning system (GPS) receivers is known to be corrupted with colored (time-correlated) noise. To make effective use of GPS information in a navigation system it is essential to model this colored noise and to incorporate additional sensing to de-correlate and eliminate its effect. In this paper frequency domain techniques are employed to generate a model for GPS noise sources. This model shows clearly what type and combination of additional sensor information is necessary to de-correlate GPS errors and to make best use of position information in navigation tasks. The frequency-domain methodology proposed has wider application in the design of sensor suites for high-performance navigation systems. Experimental results are presented demonstrating the method in fusing standard GPS latitude and longitude information with information from a velocity sensor.