A Fast Algebraic Method for Geolocating a Moving Source With Known Altitude, Resilient to TDOA/FDOA and Receiver Errors

This paper proposes a computationally efficient and highly accurate closed-form method for geolocating the position and velocity of a known altitude moving source on Earth with the TDOA and FDOA measurements. The proposed approach avoids linearizations typically used in TWLS-type solutions and instead employs the Earth model and the known altitude to locate the source. The proposed solution has three attractive aspects. It reduces computation by projecting the model equations to a lower-dimensional parameter space, improves accuracy through a sequential parameter update process, and increases numerical stability by forming a regression matrix without involving measurements. The constrained Cramer-Rao Lower Bound (CCRLB), formulated according to the WGS84 reference system, serves as a benchmark for evaluating the effectiveness of the proposed method. Simulations show the proposed method provides accurate position and velocity estimation of the moving source with higher computational efficiency than competing methods in challenging scenarios.