tailieunhanh - Báo cáo hóa học: " Research Article Nonlinear Frequency Scaling Algorithm for High Squint Spotlight SAR Data Processing"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Nonlinear Frequency Scaling Algorithm for High Squint Spotlight SAR Data Processing | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 657081 8 pages doi 2008 657081 Research Article Nonlinear Frequency Scaling Algorithm for High Squint Spotlight SAR Data Processing Lihua Jin and Xingzhao Liu Department of Electronic Engineering School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University 1-411 SEIEE Buildings 800 Dongchuan Road Shanghai 200240 China Correspondence should be addressed to Xingzhao Liu lxzsjtu@ Received 1 August 2007 Revised 27 December 2007 Accepted 12 February 2008 Recommended by A. Enis Cetin This paper presents a new approach for the squint-mode spotlight SAR imaging. Like the frequency scaling algorithm this method starts with the received signal dechirped in range. According to the geometry for the squint mode the reference range of the dechirping function is defined as the range between the scene center and the synthetic aperture center. In our work the residual video phase is compensated firstly to facilitate the following processing. Then the range-cell migration with a high-order rangeazimuth coupling form is processed by a nonlinear frequency scaling operation which is different from the original frequency scaling one. Due to these improvements the algorithm can be used to process high squint SAR data with a wide swath and a high resolution. In addition some simulation results are given at the end of this paper to demonstrate the validity of the proposed method. Copyright 2008 L. Jin and X. Liu. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Spotlight synthetic aperture radar SAR often operates in the squint mode. Several algorithms can be used for the squint mode spotlight SAR processing that is the polar format algorithm PFA 1 the range migration .