tailieunhanh - Báo cáo hóa học: " Adaptive Local Polynomial Fourier Transform in ISAR"

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: Adaptive Local Polynomial Fourier Transform in ISAR | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 36093 Pages 1-15 DOI ASP 2006 36093 Adaptive Local Polynomial Fourier Transform in ISAR Igor Djurovic 1 Thayananthan Thayaparan 2 and LjubiSa Stankovic1 1 Electrical Engineering Department University of Montenegro 81000 Podgorica Serbia and Montenegro 2 Department of National Defence Defence R D Canada - Ottawa 3701 Carling Avenue Ottawa ON Canada K1A 0Z4 Received 23 May 2005 Revised 14 November 2005 Accepted 15 November 2005 The adaptive local polynomial Fourier transform is employed for improvement of the ISAR images in complex reflector geometry cases as well as in cases of fast maneuvering targets. It has been shown that this simple technique can produce significantly improved results with a relatively modest calculation burden. Two forms of the adaptive LPFT are proposed. Adaptive parameter in the first form is calculated for each radar chirp. Additional refinement is performed by using information from the adjacent chirps. The second technique is based on determination of the adaptive parameter for different parts of the radar image. Numerical analysis demonstrates accuracy of the proposed techniques. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION The inverse synthetic aperture radar ISAR has attracted wide interest within scientific and military community. Some ISAR applications are already well known and studied. However many important issues remain to be addressed. For example suitable enhancement technique for the fast maneuvering radar targets or targets with fast moving parts is not yet known. Also standard approaches based on the Fourier transform FT fail to resolve influence of close reflectors. There are several techniques for improvement of the ISAR radar image in the case of fast maneuvering targets or in the case of objects with complex reflector geometry. Here we mention only two groups of such .