Accession Number : ADD016033

Title :   Method of Correcting Rotational Motion Error in SAR and ISAR Imagery.

Descriptive Note : Patent, Filed 1 Jul 91, patented 5 Oct 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Roth, Duane

Report Date : 05 Oct 1993

Pagination or Media Count : 14

Abstract : A method of correcting rotational motion error in SAR and ISAR imagery includes shifting the center of the image to zero doppler and thus to the center of rotation of the target being imaged, selecting a dominant scatterer at an off-center range cell to provide a phase reference, calculating the rotational motion error function from the phase of the selected scatterer, using the rotational motion error function to interpolate raw radar return image data between the original unequal angular samples to obtain equal angular samples of the target reflectivity function, and performing an image quality check and producing a value which is a relative measure of focus of the image. Also, the method includes repeating the steps starting with selecting a new dominant scatterer as a phase reference. Further, the performing step of the method includes storing and comparing the relative measures of focus provided by repeating of the steps to arrive at the corrected image which is the most focused and then saving the corrected image determined to be the the most focused.

Descriptors :   *PATENTS, *SYNTHETIC APERTURE RADAR, CELLS, ERRORS, FUNCTIONS, IMAGES, MOTION, PHASE, QUALITY, RADAR, REFLECTIVITY, ROTATION, SAVINGS, SHIFTING, SPECIAL FUNCTIONS(MATHEMATICS), STARTING, TARGETS, VALUE, RADAR EQUIPMENT, SIGNAL PROCESSING

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE