Direction finding and localization for far-field sources with near-field multipath reflections

Multipath signals are main source of error for parameter estimation in direction finding applications. In this paper, a new method is proposed for the estimation of direction-of-arrivals (DOA) of a far-field source and localization of its near-field multipath reflections in two steps. Firstly, far-field source DOA is estimated using a calibration technique. In the second step, a near-to-far field transformation is presented in order to eliminate the far-field components of the array data and obtain only near-field signal components to estimate the near-field multipath signals. The proposed method uses uniform circular array in order to give 2D DOA estimation for far-field signal and virtual uniform linear array structure is used in order to estimate locations of the near-field multipaths. The proposed method is evaluated using both ideal and close-to-real world data sets. It is shown that far and near-field source parameters are effectively estimated.