Underdetermined direct localization of emitters based on spatio-temporal processing

Without maintaining the internal constraint of the received data, conventional two-step passive localization methods are considered to be suboptimal. Following the thought of direct processing, a novel localization method based on the information of time-difference-of-arrival and angle-of-arrival (AOA) is proposed in this letter. Similar to other direct localization algorithms, the proposed method does not require the procedure of data association. By taking advantages of the spatio-temporal processing, the proposed method can handle the underdetermined scenario (i.e., the number of emitters exceeds the number of sensors from all the stations) without the prior knowledge about the number of emitters. Compared with the localization algorithms based on AOA only, the proposed method has superior performance on the condition of low signal-to-noise ratio and large bandwidth.