Detecting Moving Targets in SAR via Keystoning and Multiple Phase Center Interferometry
February 2006
P. K. Sanyal, The MITRE Corporation
D. M. Zasada, The MITRE Corporation
R. P. Perry, The MITRE Corporation
ABSTRACT
Without motion compensation, Synthetic Aperture Radar (SAR) images
of the ground are generally blurred. In 1997, MITRE reported the development
technique called the Keystone Process for removing the range migration
caused by the radial velocity component of each pixel's movement
within the scene, whether moving or stationary with respect to the ground.
When applied to multiple phase center phased array radar data, this
first pass process allows for automated detection of moving targets
via phase thresholding. Once detected in phase space, the moving targets
can be individually and automatically focused using the procedures previously
reported.
Although we can easily detect and accurately geo-locate bright (large
radar cross-sections) moving targets using either phase or amplitude
thresholding techniques, we have found that, for smaller targets, the
phase differences between the cells containing the moving target are
greatly distorted by the presence of strong ground clutter simultaneously
present in those cells. Only after the ground clutter is cancelled will
the phase difference be sufficiently dominated by the target response
to allow correct geo-positioning. Here we report on a technique whereby
the clutter may be cancelled by using multiple phase centers.
Additional Search Keywords
N/A
|
