A Simple and Accurate TDOA-AOA Localization Method Using Two Stations

This letter focuses on locating passively a point source in the three-dimensional (3D) space, using the hybrid measurements of time difference of arrival (TDOA) and angle of arrival (AOA) observed at two stations. We propose a simple closed-form solution method by constructing new relationships between the hybrid measurements and the unknown source position. The mean-square error (MSE) matrix of the proposed solution is derived under the small error condition. Theoretical analysis discloses that the performance of the proposed solution can attain the Cramér-Rao bound (CRB) for Gaussian noise over the small error region where the bias compared to variance is small to be ignored. The proposed solution can be extended directly to more than two observing stations with CRB performance maintained theoretically. Simulations validate the performance of the proposed method.