Three-Station TDOA Localization Algorithm for Fixed Ellipsoidal Height Targets

Aiming at the three-station time-difference-of-arrival (TDOA) positioning problem for targets with a fixed ellipsoidal heigh, this letter takes advantage of the fact that the influence of the earth’s curvature can be neglected in small-scale scenarios. It transforms the complex positioning on the fixed ellipsoidal heigh curved surface into simple positioning on the fixed-altitude plane. Based on the positions of the observation stations and the known ellipsoidal height, a local Cartesian coordinate system is constructed. After performing TDOA positioning in the Cartesian coordinate system, the results are transformed into geodetic coordinates (latitude, longitude, and ellipsoidal height) for output. This method avoids the defect of solving quartic equations in the traditional analytical method. Simulation analysis shows that the equivalent construction of the local coordinate system in small scenarios does not cause significant loss in positioning performance, and has certain engineering practical value.