Ambiguity Single Epoch Fixing Method Based on Prior Coordinate Constraints

Abstract

In this paper, based on the condition that the coordinates of the base station are precisely known, when the coordinate error of the rover is centimeter, a method of fixing the ambiguity single epoch under the short baseline based on GPS dual-frequency observation is proposed. Firstly, the GPS dual-frequency linear combination is searched to select a combination of (−3, 4) and (1, −1) wide lanes with longer wavelength and less noise, then, the two sets of wide lane ambiguity are directly solved by using the higher precision station distance and double difference combined observations, and the ambiguity is directly fixed by rounding method; The two fixed wide lane ambiguities are linearly combined to obtain the basic ambiguity of the GPS system, and the ambiguity is returned to the observation equation to realize the single epoch solution baseline vector. The experimental results show that the proposed method can achieve single-epoch fixation of ambiguity when the error of each direction of the rover coordinates is centimeter, and for satellites with large observation noise can be eliminated by gross error detection, thus ensuring the reliability of the single epoch positioning solution.