Patent ID: 8706441

Claim:
A system for evaluating an area portion located behind a structure having one or more openings formed between elements of the structure, the system comprising: one or more sources of electro-magnetic radiation adapted to illuminate a portion of the structure and/or to illuminate the area portion via one or more openings while a relative movement is introduced between the structure and the system; multiple non-coherent detectors adapted to detect electro-magnetic radiation returned from the portion of the structure and/or from the area portion behind the structure; a computing unit adapted to: determine, in response to measured electro-magnetic radiation returned from the portion of the structure, an exact location and orientation of the system relative to the structure; retrieve a reference simplified representation of the area portion behind the structure, said reference simplified representation corresponding to the determined exact relative location and/or orientation of the system, thus giving rise to a corresponding reference simplified representation; generate a simplified representation of said area portion behind the structure, said simplified representation corresponding to the determined relative exact location and/or orientation of the system and indicative of measured intensity and time of arrival of multiple radiation pulses returned from the area portion; and evaluate said area portion behind the structure by comparing said simplified representation of said area portion and said corresponding reference simplified representation of said area portion, wherein differences between said representations are indicative of one or more changes in said area portion.