TDOA-FDOA source geolocation using moving horizon estimation with satellite location errors

This paper considers estimating the trajectory of a moving source on Earth using time difference of arrival (TDOA) and frequency difference of arrival (FDOA) measurements obtained over time at multiple satellites. The known satellite locations are subject to random errors. To cope with the source maneuver and/or temporal variations of the satellite location errors, a moving horizon estimation (MHE)-based technique is developed. It takes into account the presence of satellite location errors and estimates the source trajectory only in an iterative manner. The proposed estimator can reach the hybrid Cramér-Rao lower bound (HCRLB) under small Gaussian noises and the condition that within the estimation horizon, the source has constant velocity and the satellite location errors are fixed. Simulations corroborate the theoretical developments.