Title :
Fourier reconstruction in spotlight mode SAR imaging
Author :
Wen, Hong ; Shiyi, Mao
Author_Institution :
Dept. of Electron. Eng., Beijing Univ. of Aeronaut. & Astronaut., China
Abstract :
The spotlight mode SAR imaging procedure can be modeled in two ways. One is from the projectional information introduced from computer-aided tomography (CAT) founded on the projection-slice theorem. By quoting the concept “projection” from CAT to microwave imaging, the spotlight mode SAR can be interpreted as a narrow band tomography reconstruction problem in the far field and small rotation angle situation. Another kind of modeling in the spotlight mode SAR comes from the conventional stripmap SAR directly, in which the processed echo returns are verified to have the same Fourier information as that in the first way. From these two points of view, the spotlight mode SAR can be unified to the problem of Fourier reconstruction (FR). A common problem motion through resolution cells (MTRC) caused by relative rotation in spotlight SAR is characterized as a main factor in imaging smearing or defocusing. Data polar formatting is adopted as an effective solution either of data reconstruction or phase focusing
Keywords :
computerised tomography; fast Fourier transforms; image reconstruction; microwave imaging; motion compensation; motion estimation; radar imaging; synthetic aperture radar; tomography; CAT; Fourier information; Fourier reconstruction; computer-aided tomography; data polar formatting; data reconstruction; defocusing; far field; imaging smearing; microwave imaging; motion compensation; motion through resolution cells; narrow band tomography reconstruction problem; phase focusing; processed echo returns; projection-slice theorem; projectional information; signal focusing; small rotation angle; spotlight mode SAR imaging; stripmap SAR; Azimuth; High-resolution imaging; Image reconstruction; Image resolution; Radar antennas; Radar imaging; Radar polarimetry; Signal resolution; Synthetic aperture radar; Tomography;
Conference_Titel :
Radar, 1996. Proceedings., CIE International Conference of
Conference_Location :
Beijing
Print_ISBN :
0-7803-2914-7
DOI :
10.1109/ICR.1996.574456