A two-step algorithm for locating the emitter by FDOA

This article considers the technique of emitter localization. The main contribution is an efficient algorithm for locating the fixed emitter based on single sensor by using frequency differences of arrival(FDOA). It is a two-step algorithm. Firstly, FDOA is converted to time differences of arrival (TDOA) by integrating, and the algorithm of Chan is used to get an initial estimation of emitter localization. The localization equation based on FDOA is approximated with first order Taylor expansion at the initial estimation, and the linearized equation is solved with least-squares (LS). The error caused by initialization of FDOA is reduced in this way. Secondly, the statistical characteristics of truncation error are used to measure the location results, if it satisfy the threshold condition, output the location results, otherwise, the integration interval is adjusted and recalculated until the threshold is satisfied. Therefore, the credibility of results are improved by this way. In terms of computational complexity, only 2 more iterations are needed than the original LS, and the operation in each iteration is similar with LS. Experiments for analyzing the influence of sensor's moving trajectory, integral interval and the error comparison with other algorithms show the reliability of the proposed algorithm. The results also demonstrate the algorithm can accurately locate the emitter in 3-D with Gaussian noise of FDOA.