Research on high precision relative positioning method based on constrained baseline length of Beidou satellite navigation system

With the rapid development of Beidou satellite navigation system, the relative positioning application based on Beidou is becoming more and more widespread, and the scenario of installing two or more antennas on the carrier is also concerned. If the prior baseline length constraint information that can be accurately measured in advance is strictly integrated into the observation model of relative positioning, it can not only effectively improve the strength of the observation model and enhance the reliability of the whole cycle ambiguity calculation, but also improve the accuracy of relative positioning to a certain extent. How to fully integrate the prior baseline length constraint information into the observation model and design a reasonable and effective full-cycle ambiguity search strategy under the new objective function has become the difficulty and challenge to realize the relative positioning technology of baseline length constraint. In order to improve the reliability of the relative positioning solution, this paper makes full use of the baseline length information between the two antennas of the mobile carrier, and provides a high precision relative positioning method with baseline length constraints. The standard LAMBDA algorithm is extended to the relative location of the baseline length constraint, and the effective search of the whole week ambiguity is realized. The experimental results show that the proposed method uses the base line length information of double antenna which is not fully used in the actual scene to improve the relative positioning solution effect, and has higher reliability than the traditional unconstrained solution.