Gating and robust EKF based target tracking in mixed LOS/NLOS environments

A simple but effective approach based on gating and robust extended Kalman filtering (EKF) is proposed for target tracking in mixed line-of-sight and non-line-of-sight (LOS/NLOS) environments, using time-of-arrival (TOA) measurements. Utilizing a gating based detection method determined by the statistical properties of the TOA measurements, a confidence region is derived. Most of the LOS TOA measurements can be effectively selected from all mixture measurements using the properly defined confidence region. These selected LOS TOA measurements are then passed on to the dynamic robust EKF to do the target tracking. Simulations have shown the proposed tracking approach has outperformed both the classic rEKF as well as a recent target tracking approach. Moreover, the proposed approach does not require any statistical knowledge of the NLOS error and only assumes that the standard deviation of the LOS noise is known.