Multiresolution imaging with quadtree backprojection

The quadtree backprojection is an efficient space-time synthetic aperture radar (SAR) imaging algorithm that is based on the spectral decomposition of SAR data. Normally the quadtree backprojection is represented as a multiple stage imaging process that performs the space-time domain imaging over a number of sub-patches separately at each stage. By representing the contents of each sub-patch with a predefined energy function, it is possible to form a sequence of multi-resolution images. In this paper, we discuss various applications where this quadtree imaging can be applied to provide the multiresolution imaging. These include SAR, tomographic medical imaging and beamforming.