Patent ID: 7116265

Claim:
A synthetic aperture radar for acquiring a target object in a scene and computing a classification for said target object, said synthetic aperture radar comprising: analog to digital converters for converting a plurality of radar returns from said scene into a digital stream; a computer for: converting said digital stream into a synthetic aperture image; extracting portions of said synthetic aperture image containing said target object to obtain a target region; applying noise compensation to said target region to obtain a noise compensated target region; applying anisotropic diffusion to said noise compensated target region to obtain an isolated target object; applying a low pass filter to said isolated target object to obtain a low pass filtered isolated target; applying gray scale segmentation to said low pass filtered isolated target to obtain a segmented target; applying object signal extraction to said segmented target to obtain a segmented image of said target subject, said segmented image having a periphery; selecting a plurality of random first chords across said periphery; measuring each of said first chords to obtain a plurality of first dimensions; computing for each of said first chords a second chord across said periphery thus forming a plurality of pairs of chords; measuring said second chords to obtain second dimensions; computing for each of said pairs of first chords and second chords the ratio of said first dimension to said second dimension to obtain a plurality of first values; computing the logarithm of said first values to obtain a plurality of logarithmic values; recording said first values in a first histogram; recording said logarithmic values in a second histogram; extracting a first vertex list from said first histogram; extracting a second vertex list from said second histogram; combining said first vertex list and said second vertex list to obtain a first signature, said first signature indicative of said classification of said object target.