Design of INS aided receiver integrity monitoring algorithm (ARIM) for GNSS integrated navigation systems

This paper describes the design of INS Aided Receiver Integrity Monitoring (ARIM) algorithm for GNSS integrated navigation systems. Inertial navigation systems typically use navigation grade accelerometers and gyroscopes for high reliability applications such as launch vehicles. Usage of GNSS receivers along with low cost IMUs with their measurements instances synchronized provides feasibility of realizing low-cost integrated navigation systems without compromising in performance or reliability. While the usage of GNSS receiver helps to overcome the inaccuracies caused by low cost IMU, the output of the inertial navigation system can also be used for validating the measurements taken by the GNSS receiver especially during spoofing scenarios. Validation of pseudorange measurements in this manner gives computational advantage over the conventional RAIM (Receiver Autonomous Integrity Monitoring) algorithm. The test results are a good indication of the usefulness of the algorithm in different scenarios where measurement errors are possible. In summary, ARIM algorithm presented in this paper provides an effective scheme for validating GNSS pseudorange and deltarange measurements under different possible error scenarios including spoofing and improves the overall reliability of the GNSS integrated navigation system.