Relative RAIM Based on IMM

Abstract

With the definitude of the GNSS integrity requirement and the development of the integrity augmentation technology, GNSS integrity augmentation technology has developed a whole integrity solution from Satellite Based Augmentation System (SBAS), Ground Based Augmentation System (GBAS) to Airplane Based Augmentation System (ABAS) today. However, any single integrity augmentation technique has its shortage. It may subject to certain restrictions when used alone. As a result, the combination of the different types of integrity augmentation technology is a reasonable solution to overcome their shortcomings. Relative Receiver Automatically Integrity Monitoring (RRAIM) is one of such technology with the mixture of SBAS and ABAS. With the combination of integrity and correction of ground stations and carrier phase observations, the RRAIM technology overcomes both the problem of the SBAS information delay and the shortcoming of the ABAS performance affected by GNSS satellites distribution. But current RRAIM methods are basically based on LS manner, which may suffers the noise introduced by carrier phase observations. Aiming at this problem, this paper introduces a RRAIM methods are basically based on filter, and to increase the RRAIM performance and protect the navigation integrity and flight operation safety.