Research on ambiguity solution integrity monitoring for moving base RTK

Ambiguity integrity monitoring is very important for some navigation applications that utilize high-precision carrier-phase differential positioning technology, which can greatly improve the safety of navigation applications. At present, the methods of solving the ambiguity problem are relatively mature. However, in different relative positioning scenarios, the ambiguity solution varies due to the existence of different relative positioning modes, which can lead to difficulty fixing the ambiguity. Therefore, it is necessary to analyze the difference in position domain integrity risk considering the cycle resolution in the carrier phase under different relative positioning modes and improve the integrity risk calculation algorithm. This paper utilized the actual Beidou Navigation Satellite System (BDS) positioning data collected from Dongying Airport to simulate different relative positioning modes by using two different vehicles, and the influence of different relative positioning modes on ambiguity fixing was analyzed. Furthermore, we develop an improved algorithm framework for position-domain integrity risk-based ambiguity considering the cycle resolution in carrier-phase navigation systems. The improvements are as follows: (1) LAMBDA is used to analyze the ambiguity in different relative positioning modes; (2) Two vehicles are used to build a test environment and simulate relative positioning scenarios in different modes; (3) The ambiguity fixing process is investigated, the probability of correctly fixing the ambiguity is calculated, and the effects of incorrectly fixed ambiguity solutions on the position-domain integrity risk are compared; (4) An integrity algorithm framework is proposed to establish an integrity monitoring scheme suitable for the moving-base RTK relative positioning mode. The results provide a reference for more complex and high-precision positioning technology in navigation applications.