A solution separation RAIM scheme based on adaptive clock-bias model

Because of the loss of availability in the traditional integrity monitoring algorithm, a solution separation RAIM (Receiver Autonomous Integrity Monitoring) scheme based on adaptive clock-bias model with flexible smoothing window is presented. The proposed CASS (Clock-bias Aided Solution Separation) RAIM improves the availability of integrity monitoring by the means of adjusting the smoothing time constant in the adaptive clock-bias model. The whole integrity monitoring scheme with the combination of adaptive clock model and the solution separation is analyzed. The simulation and real-data test results show that, compared with traditional RAIM, the level of availability is greatly improved by the proposed CASS algorithm. The vertical positioning accuracy is improved by about 27%. However, the performance of fault detection is nearly the same as the one of traditional RAIM.