Resolution Analysis of Circular SAR with Partial Circular Aperture Measurements

Radar resolution is considered for the targets near-axis with circular synthetic aperture measurements. Circular SAR (CSAR) imaging with partial circular apertures is used in many practical applications and laboratory experiments, but its resolution is hardly investigated. In this paper, an analytic expression is derived for the spatial resolution for a circular aperture of less than 360 degrees, and the general result can be applied to the special case that CSAR imaging is made with full apertures. Unlike CSAR imaging with full apertures, the ground plane resolution cell area of partial apertures will be an ellipse instead of a circle.