DOA estimation for the near-field correlated sources with interpolated array technique

The problem of estimating the directions of arrival (DOAs) of perfectly correlated signals in the near-field (the Fresnel region of the array aperture) is considered. A new estimation algorithm which combines the ideas of spatial smoothing and array interpolation in the near-field is derived. The proposed technique can be applied to uniform linear array geometries in the near-field when the ranges of the sources are similar. Making use of interpolated array technique, we can place the dasiavirtual elementspsila of the interpolated array as a uniform linear array approximated in the far field, and estimate the bearing of correlated signals using the virtual array geometries. The performance of this new algorithm was evaluated by extensive simulations.