Passive geolocalization of radio transmitters: Algorithm and performance in narrowband context

Passive localization commonly consists of a two steps strategy. In the first step, intermediate parameters, often called measurements (such as angles of arrival (AOA), times of arrival (TOA), etc.) are measured on several base stations equipped with sensor arrays. In a second step, the transmitted intermediate parameters are then used to estimate the position at a central processing unit. Such approach is suboptimal. To overcome this limitation, one step algorithms were recently proposed. They exploit simultaneously all received signals of all base stations seen as a global array in order to provide the source positions directly. In this paper, we propose an original one step algorithm called global MUSIC approach (GMA). The GMA offers better performance in narrowband context. Moreover it does not require the use of filter banks in the wideband signal context, contrary to the recently proposed direct position determination (DPD). GMA appears to outperform the DPD in wideband context. We also investigate in this paper by means of a Cramer-Rao bound analysis the potential gain achievable by a one step approach compared to a conventional two steps approach. Finally, numerical results illustrate the improvement of the proposed method compared to existing techniques in terms of location error and robustness to the time-bandwidth product.