Multi-Stage Processing for UHF/VHF SAR Image Formation

Current radar technology for the detection, location and targeting of fixed and mobile targets hidden by foliage or camouflaged is severely limited. These systems typically operate in the UHF/VHF band using ultra-wideband, synthetic aperture techniques to obtain high resolution images of concealed targets. Algorithms used to form images are very complex in order to compensate for platform motion effects such as differential range curvature, widebeam motion compensation, autofocus, and environmental effects such as RF interference. TSC, along with our subcontractor, ERIM, proposes to develop, evaluate, and compare various image formation algorithms. A 2-stage process will be emphasized, in which data is first formed into a number of smaller subpatches, then combined to obtain the full desired aperture. Techniques to be investigated will include Range Migration Algorithm (RMA), RMA with Subchirp Processing, Planar Subarray Processing and BackProjection. As a Phase I goal, image formation algorithms will bedefined and evaluated for performance against a set of metrics. Signal processor architectures and COTS hardware with the requisite power necessary for real-time implementation will be investigated. At the conclusion of Phase I, one or more algorithm suites and a COTS hardware implementation will be recommended for development in Phase II.