摘要: Using autocorrelation information of the pseudorange errors generated by selective availability (SA) frequency dithering, we have constructed a simple first order stochastic model for SA effects. This model has been used in a Kalman filter to account for the stochastic behavior of SA dithering in estimating satellite clock information in wide area differential GPS. We have obtained fifteen percent improvement in the user positioning using the correlation information on the satellite clock information in a Kalman filter, when comparing the results obtained using a regular least square estimation.