LAUSR

ArcSAR is a ground-based synthetic aperture radar (GBSAR) that has recently been receiving increasing interest in the scientific literature. While the conventional GBSAR exploits the movement of an antenna along a linear rail to synthesize a large aperture, an ArcSAR exploits the spatial diversity of the data acquired by an antenna fixed to a rotating arm. The great advantage of ArcSAR is its capability to synthesize images at 360° with a constant resolution in azimuth. In this paper, the authors propose and test a new focusing algorithm that does not require to operate in the far field and neither with narrow beam antennas; moreover, it is flexible enough to focus on any plane (not necessarily on the rotation plane) as well as in the whole 3-D space. Furthermore, the authors demonstrate theoretically and experimentally that ArcSAR images can be affected by a “defocusing effect” of the targets far from the rotation plane, which has to be taken into consideration when designing such radars.