利用時頻轉換分析處理合成孔徑雷達之移動目標物影像

簡易檢索 / 詳目顯示

回結果列表

研究生：	王偉丞 Wei-Cheng Wang
論文名稱：	利用時頻轉換分析處理合成孔徑雷達之移動目標物影像 Joint Time-Frequency Analysis for SAR Imaging of Moving Targets
指導教授：	陳錕山 Kun-Shan Chen 曾裕強 Yu-Chang Tzeng
口試委員:
學位類別：	碩士 Master
系所名稱：	地球科學學院 - 太空科學研究所 Graduate Institute of Space Science
畢業學年度：	96
語文別：	中文
論文頁數：	111
中文關鍵詞：	時頻轉換、合成孔徑雷達、移動目標物
外文關鍵詞：	moving targets, Synthetic Aperture Radar(SAR), time-frequency analysis
相關次數：	點閱：27 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

合成孔徑雷達是一種微波遙測系統，其目的在於提供高解析的地表影像，尤其在固定的地表目標物與背景下，確實提供了很好的影像品質。然而在地表目標物為移動的情況之下，影像將變得模糊不清，且移動目標物與雷達間的都卜勒頻率與固定目標物與雷達間的都卜勒頻率相較之下變得複雜許多，而讓分析移動目標物的影像變得相當棘手與困難。
本研究主要利用時頻轉換方法，一種已廣泛應用於許多領域的結合時域與頻域的分析方法，來針對合成孔徑雷達移動目標物模擬影像作分析。主要利用從雷達訊號經處理後所得到的時頻平面圖，可得到移動目標物的都卜勒斜率與都卜勒中心頻率的偏移，再搭配推導出來的移動目標物都卜勒頻率公式，來作移動目標物的速度估算。
本實驗先從單一點移動目標物模擬影像起始，分別作不同方向與不同速度的估算，再加入多個點移動目標物的模擬影像，再用相同的估測方式估測一遍，以期達到可以使估測方法應用在不同情況的移動目標物模擬影像上，接著比較估測出來結果與當初設定的速度是否吻合。最後再利用真實影像來作估算，來驗證出此估測方法的實用性。

Synthetic aperture radar (SAR) is a kind of microwave remote sensing system. Its purpose lies in offering the high quality image of the earth''s surface. But under the circumstances of moving targets, the image introduces smearing, and Doppler frequency between moving targets and radar becomes more complicated than it between stationary targets and radar. Then the analysis for imaging of moving targets is a difficult problem.
This research is mainly to use joint time-frequency analysis (JTFA) that combines analysis in time domain and in frequency domain, to analyze SAR imaging of moving targets. It has been applied successfully to many areas of signal processing. By using
JTFA, we can obtain the targets’ Doppler rate and Doppler centroid frequency from time-frequency plane figure of compressed radar signal. And combining to derive formula of targets’ Doppler frequency, we can estimate the velocity of moving targets.
This study started from the estimation of velocity on simulated SAR images of single-target, followed by estimating velocity on simulated SAR images of multi-target, including moving targets move at different velocities and in different directions. Then we compare whether the estimation results are similar to the simulated velocity or not. Finally, we estimate it on real image to confirm the practicability of the analysis.

摘  要............................................i
Abstract..........................................ii
誌  謝............................................iii
目  錄............................................iv
圖 目 錄..........................................vi
表 目 錄..........................................ix
第一章  緒論.......................................1
1 研究動機與目的.................................1
2 文獻回顧與研究方法概述.........................2
3 論文架構.......................................4
第二章  時頻轉換分析...............................5
1 簡介...........................................5
2 STFT...........................................6
2.1 數學式推導...................................6
2.2 STFT的特性...................................9
3 CWT...........................................10
4 WVD...........................................12
4.1 數學式推導..................................12
4.2 WVD的特性...................................14
5  STFT與WVD的分析比較..........................17
第三章  雷達系統理論..............................22
1 雷達系統......................................22
2 解析度........................................24
2.1 距離方向解析度..............................24
2.2 方位方向解析度..............................26
3 合成孔徑雷達原理..............................27
4  sub-aperture分析.............................30
5 脈波訊號壓縮..................................32
第四章  合成孔徑雷達..............................34
1 合成孔徑雷達與移動目標物的幾何關係............34
2 合成孔徑雷達發射訊號..........................35
2.1 鳥鳴訊號 (chirp signal).....................35
2.2 發射訊號....................................35
3 合成孔徑雷達回波訊號..........................37
3.1 距離方向回波訊號............................37
3.2 方位方向回波訊號............................38
3.3 天線場型....................................39
4 固定目標物的雷達回波分析......................40
4.1 固定目標物的雷達回波........................40
4.2 固定目標物的二維回波訊號....................41
5 移動目標物的雷達回波分析......................42
5.1 移動目標物的雷達回波........................42
5.2 移動目標物的都卜勒頻率......................44
5.3 移動目標物的二維回波訊號....................46
6 回波訊號的處理	................................47
6.1 處理流程....................................48
6.2 數學表示式與固定點目標物範例................49
6.3 移動點目標物範例............................55
第五章  模擬結果與速度估測........................60
1  估測方法架構流程.............................60
1.1 時頻轉換分析架構流程........................60
1.2目標物影像模糊長度分析架構流程...............62
1.3 sub-aperture分析架構流程....................64
2 模擬參數介紹..................................66
3 單一點目標物模擬影像與速度估測................67
3.1 方位方向的移動目標物模擬影像及速度估測......68
3.2 距離方向的移動目標物模擬影像及速度估測......74
4 多點目標物模擬影像與速度估測..................77
4.1不同方位線上方位方向移動的多點目標物.........77
4.2 結合兩個移動方向的多點目標物................86
4.3 同一方位線上不同移動速度的多點目標物........93
5 比較與討論...................................100
6 真實影像估測.................................101
第六章  結論與未來展望...........................107
1  結論	........................................107
2 未來展望.....................................108
參考文獻.........................................110

                                

[1] Ainsworth, T. L., R. W. Jansen, J. S. Lee, and R. Fiedler, “Sub-aperture analysis of high-resolution polarimetric SAR data,” Proceedings of IGARSS’99, vol.1, pp. 41-43, 1999.
[2] Auger, F., P. Flandrin, P. Goncalves, and O. Lemoine, Refernce Guide to:“Time-Frequency Toolbox for Use With Matlab”, 1995.
[3] Barbarossa, S., A. Farina, “Detection and imaging of moving objects with synthetic aperture radar, Part 2: Joint time-frequency analysis by Wigner-Ville distribution,” IEE Proceedings F, vol.139, no.1,pp.89-97, 1992.
[4] Chen, V. C., “Joint time-frequency analysis for radar signal and imaging,” Proceedings of IGARSS’07, pp.5166-5169, 2007.
[5] Chen, V. C., H. Ling, Time-Frequency Transforms for Radar Imaging and Signal Analysis, Boston: Artech House, 2002.
[6] Chen, V. C., H. Ling, “Joint time-frequency analysis for radar signal and image processing,” IEEE Signal Processing Magazine, vol. 16, No.2, pp. 81-93, 1999.
[7] Chen, V. C., S. Qian, “Joint time-frequency transform for radar range-Doppler imaging,” IEEE Transactions on Aerospace and Electronic Systems, vol.34, no.2, pp.486-499, 1998.
[8] Cumming, I. G., F. H. Wong, Digital Processing of Synthetic Aperture Radar Data: Algorithms and Implementation, Boston:Artech House, 2005.
[9] Ding, Y., D. C. Munson, “Time-frequency methods in SAR imaging of moving targets,” Proceedings of IEEE ICASSP’02, vol. 3, pp.2881-2884, 2002.
[10] Ding, Y., N. Xue, and D. C. Munson, “An analysis of time-frequency methods in SAR imaging of moving targets,” Proceedings of IEEE Sensor Array and Multichannel Signal Processing Workshop, pp.221-225, 2000.
[11] Flandrin, P., Time-Frequency/Time-Scale Analysis, Academic Press, 1999.
[12] Haykin, S. S., Advances in Spectrum Analysis and Array Processing Vol.1, New Jersey: Prentice Hall, 1991.
[13] Kelly, J., T. L. Ainsworth, and J. S. Lee, “Subaperture analysis of polarimetric SAR imagery”, Proceedings of IGARSS’07, pp.5190-5193, 2007.
[14] Kersten, P. R., R. W. Jansen, K. Luc, and T. L. Ainsworth, “Scene analysis of SAR images using joint time-frequency analysis,” Proceedings of IGARSS’06, pp.4176-4179, 2006.
[15] Kersten, P. R., R. W. Jansen, K. Luc, and T. L. Ainsworth,“Implementation of the time-frequency distribution series for SAR
applications,” Proceedings of IGARSS’06, pp.3587-3590, 2006.
[16] Kersten, P. R., R. W. Jansen, K. Luc, and T. L. Ainsworth, “ Motion analysis in SAR images of unfocused objects using time-frequency methods,” IEEE Geoscience and Remote Sensing Letters, vol. 4, no.4, pp. 527-531, 2007.
[17] Kersten, P. R., R. W. Jansen, and T. L. Ainsworth, “The cross time-frequency distribution series for synthetic aperture radar (SAR) applications,” Proceedings of IGARSS’07, pp.5178-5181, 2007.
[18] Son, J. S., G. Thomas, and B. C. Flores, Range-Doppler Radar Imaging and Motion Compensation, Boston: Artech House, 2001.
[19] Soumekh, M., Synthetic Aperture Radar Signal Processing with MATLAB Algorithms, John Wiley & Sons, 1999.
[20] 邱哲彥，“線性多偏極掃描式合成孔徑雷達影像模擬”，碩士論文，太空科學研究所，國立中央大學，2007。
[21] 朱得銘，“利用合成陣列技術進行雷達影像方位方向之聚焦處理”，碩士論文，電子工程學系碩士班，國立聯合大學，2006。

簡易檢索 / 詳目顯示

相關論文