Recursive SAR imaging

Publisher Website
Google Scholar
Abstract
We investigate a recursive procedure for synthetic aperture imaging. We consider a concept in which a SAR system persistently interrogates a scene, for example as it flies along or around that scene. In traditional SAR imaging, the radar measurements are processed in blocks, by partitioning the data into a set of non-overlapping or overlapping azimuth angles, then processing each block. We consider a recursive update approach, in which the SAR image is continually updated, as a linear combination of a small number of previous images and a term containing the current radar measurement. We investigate the crossrange sidelobes realized by such an imaging approach. We show that a first-order autoregression of the image gives crossrange sidelobes similar to a rectangular azimuth window, while a third-order autoregression gives sidelobes comparable to those obtained from widely-used windows in block-processing image formation. The computational and memory requirements of the recursive imaging approach are modest - on the order of M • N 2 where M is the recursion order (typically ≤ 3) and N 2 is the image size. We compare images obtained from the recursive and block processing techniques, both for a synthetic scene and for X-band SAR measurements from the Gotcha data set.

This publication has 0 references indexed in Scilit: