Passive localization of near-field sources using cumulant

Passive source localization is one of the issues in array signal processing fields. When some source lies in the Fresnel region of the array (i.e., near-field), the wavefront of the source must be characterized by both the direction-of-arrival (DOA) and range. To localize near-field sources, some classical far-field source localization methods are modified to estimate DOA and range at the costs of array aperture, which contains two hands: i) quarter-wavelength constraint is imposed on the intersensor spacing and ii) fewer sources in the near-field case are localized from an array of given sensor number than those of the far-field case. In addition, it is necessary to match two separately estimated electric angles (function of DOA and range) of multiple near-field sources, i.e., encountering parameter match problem.