GPS Modeling in Frequency Domain

Although DGPS provides positioning information with high precision, when DGPS is unavailable in some situations, stand-alone GPS has to be used in vehicle navigation. The accuracy of standard GPS is low due to position measurement errors. This paper presents a frequency domain modeling approach to model GPS errors and increase GPS positioning accuracy. This approach models GPS errors using shaping filter. External sensors are employed to reduce GPS errors. This paper also presents an approach to select external sensors to meet the quality requirements of positioning system.