Recursive estimation of emitter location using TDOA measurements from two UAVs

This paper considers the recursive estimation of emitter location using time difference of arrival measurements formed by the correlation of signals received by two unmanned aerial vehicles. The time difference of arrival measurement defines an hyperbola of possible emitter locations. This hyperbola is used as a measurement in a nonlinear Alter. The performance of two such filters, an extended Kalman filter (EKF) and an unscented Kalman filter (UKF), is analysed for a stationary and moving emitter and compared with the Cramer-Rao lower bound. The UKF performs generally better than the EKF, but both algorithms suffer from diverged tracks.