The airborne GPS receiver is used to get the position information of an aircraft in the calibration flight test of radars. The position information is obtained by the carrier phase differential GPS techniques (CDGPS), which needs a network of GPS receivers as reference stations. Usually at least two GPS receivers are needed to get position information of decimeter level precision. In order to evaluate the precision of positioning only based on the data of single airborne GPS receiver, a post-processing approach using precise point positioning (PPP) techniques is developed. The algorithm only needs zero differenced dual-frequency pseudo-range and phase observations of the airborne GPS receiver to work, along with the precise orbit products of International GNSS Service (IGS) or the observation data of IGS stations. Two kinds of alternative Kalman filters based on white noise model and current statistic model respectively, are used in the algorithm and compared in this paper. The results from the simulation data of the flight test scheme demonstrate that, the two filters can get similar results to each other and both of them can achieve equivalent precision to the traditional CDGPS techniques. The results mean that the network of reference GPS stations is unnecessary if the post-processing PPP algorithm is used.
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