Method of walk-through security inspection and system thereof

A security inspection system comprising a signal acquisition unit operatively connected to data processing unit, wherein:

• the signal acquisition unit comprises a plurality of ultra-wideband transmitters and receivers arranged at both sides of a walk-through inspection space and configured to scan the inspection space along with an inspected person passing there through, to yield collected data informative of scattered signals in association with respective channels;
• the data processing unit is configured:
• upon dividing the inspection space into a plurality of subspaces such that each voxel in the inspection space belongs to one and only one subspace, to provide image reconstruction separately for each subspace of the plurality of the subspaces, wherein image reconstruction for voxels residing in a given subspace is to be provided using collected data corresponding to a set of channels selected for the given subspace in accordance with predefined rules, wherein selecting the set of channels comprises:
• calculating one or more parameters of specular points of channels reflected by a virtual equi-area tessellated sphere co-centric with a given subspace;
• identifying channels with the calculated one or more parameters matching channel-dropping criteria defined to the given subspace thereby giving rise to omitted channels;
• generating a set of channels selected for the given subspace, the generating comprising excluding the omitted channels from further processing for image reconstruction and;
• to use image reconstruction results for detecting a concealed object.