Unscented Kalman Filter Based Protection Level for the Integrity of Space Launch Vehicle

A horizontal protection level (HPL) calculation framework for the integrity monitoring of a highly non-linear dynamic system (space launch vehicle) is presented. The protection level is calculated after outlier detection is performed in the faulty measurement sets. The Unscented Kalman Filter (UKF) concept is adopted for the state estimation and protection level calculation for the launch vehicle. The minimum detectable bias obtained from the outlier detection strategy and the innovation covariance from the UKF are used to calculate the protection level which satisfies the conditions of nominal operations. This framework is tested using simulated global navigation satellite system (GNSS) pseudorange measurements and the second order differential equations of the launch vehicle dynamics.