A Method for Detection of Walls and Large Flat Surfaces in Through-the-Wall SAR Imaging

Abstract

Through-the-wall imaging using synthetic aperture radar (SAR) provides high-resolution images of hidden objects behind the walls which has many applications in military, security, and rescue operations. Besides imaging of hidden objects, detection of walls provides complete map of buildings’ interiors features such as rooms, corridors, and hidden pathways which is required for path planning and threat assessment in rescue and military operations. Unlike targets with small surface size, each point on flat walls provide reflection at certain directions. In this case, forming the image using the entire large aperture has a destructive effect on the image of some points on the wall surface. As a result, in high resolution SAR, the walls are imaged as few discrete points instead of solid lines which may be interpreted as few discrete closely spaced targets. In this paper, a method is presented to discriminate walls and objects with large flat surfaces from limited size objects and determine the existing walls locations and orientations inside the imaged area.