Accession Number : ADA306576

Title :   Characterizing and Correcting Media-Induced Focus Errors in Synthetic Aperture Radar Imagery.

Descriptive Note : Final rept. Nov 93-Apr 94,

Corporate Author : INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA

Personal Author(s) : Gilbert, Gerald ; Braunstein, Matthew ; Ralston, James

PDF Url : ADA306576

Report Date : APR 1994

Pagination or Media Count : 29

Abstract : Recently, considerable attention has been directed to the use of airborne synthetic aperture radar (SAR) for detecting both large and small underground objects. The reconstruction of images of buried objects from SAR data, however, often relies on assumptions and algorithms developed in the context of free space radar propagation. Although in some cases the implicit assumption of free space propagation can lead to acceptable results, in other important cases it will result in severe degradation to images of underground objects. In this paper we investigate the conditions under which significant improvements to image quality result if proper account is taken of the detailed effects of the soil medium on radar wave propagation. These effects are analyzed both in terms of the refraction of plane waves and via reference to general analytic solutions to Maxwell's equations. Quantitative predictions of the improvement in buried target image focusing are presented for some realistic data collection scenarios, corresponding to airborne and ground based SAR or microwave holography.

Descriptors :   *SYNTHETIC APERTURE RADAR, *RADAR IMAGES, *BURIED OBJECTS, ALGORITHMS, PREDICTIONS, MICROWAVES, ELECTROMAGNETIC WAVE PROPAGATION, SOILS, HOLOGRAPHY, QUALITY, DATA ACQUISITION, FOCUSING, REFRACTION, RADAR TARGETS, MAXWELLS EQUATIONS, PLANE WAVES, UNDERGROUND.

Subject Categories : Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE