Failure detection approach applying to GPS autonomous integrity monitoring

In recent years, there has been a growing interest within the potential use r community in applying GPS to a variety of high-precision navigation probl ems such as aircraft nonprecision approach, river and harbour navigation, r eal-time or kinematic surveying, etc. In view of more and more GPS applicat ions, the reliability of GPS is at issue. This promotes the need for severa l proposed receiver autonomous integrity monitoring (RAIM), GPS integrity c hannel (GIC), and wide area augmentation system (WAAS) schemes. The authors propose an approach for autonomous GPS satellite failure detection. The me thod exploits total least squares (TLS) optimisation to achieve fault detec tion. The traditional least squares approach fails to address the change in the data matrix associated with GPS satellite constellation. This drawback is shown to be remedied by the total least squares method. The proposed me thod can further be extended to account for failure isolation in which fail ed GPS satellites are identified and hence excluded in positioning.