基于IDL的双基地SAR成像软件的设计与实现
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摘要
双基地合成孔径雷达是一种新的雷达体制,其发射机和接收机安装在不同的平台上,具有作用距离远,安全性,抗干扰性,抗截获性能好等优点,越来越受到各国的重视。但国内对于双基地SAR的数据应用,包括成像处理和数据可视化分析都还处于一个比较低的水平。本文利用第四代可视化语言的代表IDL,开发出一种针对双基地SAR的成像软件,可对双基地SAR的数据进行成像和可视化分析,对于国内的双基地SAR研究及IDL在双基地SAR领域中的应用均有着十分明显的意义。本文的主要工作内容如下:
首先,对双基地SAR的成像机理和成像算法进行相应的研究和分析,以此作为成像软件开发的理论和算法基础。在成像机理方面,首先建立了任意飞行模式下双基地SAR的几何模型和回波模型,详细分析了其距离史、多普勒特性及空间分辨率特性。在成像算法方面,研究和分析了非移变模式下的双基地RD算法和BP算法,给出了两种算法的原理,并针对RD算法给出了两种多普勒参数估计方法:最大对比度算法和基于最小熵的离散傅立叶算法的原理及实现过程。
其次,以双基地SAR成像机理和成像算法的研究为基础,分析并确定了双基地SAR成像软件的功能需求。针对软件的功能需求,对软件的总体框架作出设计,并对构成软件主体的五大功能模块:加密引导模块、输入模块、主控模块、数据处理模块和输出模块结合IDL的特点分别作出详细的设计。利用IDL的GUI设计方法和数据读入方法,给出了软件的加密引导模块、输入模块和主控模块的具体设计方案;利用本文中所研究的双基地SAR成像理论和成像算法,结合IDL的数据处理特点,改进了仿真数据的生成程序,并给出了RD算法和BP算法的数据处理流程;最后利用IDL的对象图形系统完成了软件输出模块,包括图像显示系统、图像处理系统、数据采集和分析系统及数据保存系统的设计。
最后,利用上述的设计方案,成功实现了成像软件的各个主要功能,并通过具体实例进行了展示。实现功能包括:对非移变模式下的双基地SAR利用RD算法和BP算法进行理论仿真和实测数据成像、每种算法的分步调试和结果显示、图像处理及数据采集分析。
Bistatic Synthetic Aperture Radar is a kind of new radar system, its transmitter and receiver are installed on different platforms, with the advantages of operating long range, the security, anti-interference and anti-interception, is paid more and more attention to by various countries. However, in our country, the application of bistatic SAR data, imaging processing and analysis of data visualization are still at a relatively low level. The representative of the fourth generation of visual languages IDL is utilized to develop a kind of imaging software for bistatic SAR, which can imaging and visual analysis to the data of bistatic SAR, there is a very obvious meaning to domestic bistatic SAR research and application of IDL in bistatic SAR field. The main work of this paper is as follows:
First of all, the mechanism and algorithm of imaging of bistatic SAR are correspondingly researched and analyzed, which is regarded as the base of imaging software development. In mechanism of imaging, the geometry models and the echo models of the bistatic SAR are set up under wanton flight mode at first; range history, the characteristic of Doppler and the characteristic of spatial resolution are analyzed in detail. In algorithm of imaging, the bistatic RD and BP algorithm are studied under Translationally Invariant mode, provide the principles of two kinds of algorithms, and provide two Doppler parameters estimation methods for RD algorithm: the principle of the greatest contrast and based on minimum entropy algorithm for the Discrete Fourier algorithm.
Secondly, the research on the mechanism and algorithm of bistatic imaging SAR is regarded as the foundation, the function demand of imaging software is analyzed and confirmed. Direct against the function demand for the software, the overall frame of the software is designed, and the five major function module are separately designed with combination of the characteristic of IDL, and they are Encrypt and guide module, import module, top management module , data processing module and export module. To utilize the methods of the GUI design and data input, Encrypt and guide module, import module and top management module are provided with the concrete design plan; Combining the theory and algorithm of bistatic SAR and the characteristic of data processing of IDL, the generating program of the emulation data have been improved, the data processing procedure of RD algorithm and BP algorithm is also afforded; finally the export module is finished to utilize the object graphic system of IDL, including the design of imaging display system, image process system , data acquisition and analysis system and data reservation system.
Finally, each chief function of imaging software are realized and has been shown through the concrete examples. The function realized includes: to utilize RD algorithm and BP algorithm to carry on theory emulation and imaging based on measured data under Translationally Invariant mode, debug every algorithm step by step and display results, data processing and data analysis.
首先,对双基地SAR的成像机理和成像算法进行相应的研究和分析,以此作为成像软件开发的理论和算法基础。在成像机理方面,首先建立了任意飞行模式下双基地SAR的几何模型和回波模型,详细分析了其距离史、多普勒特性及空间分辨率特性。在成像算法方面,研究和分析了非移变模式下的双基地RD算法和BP算法,给出了两种算法的原理,并针对RD算法给出了两种多普勒参数估计方法:最大对比度算法和基于最小熵的离散傅立叶算法的原理及实现过程。
其次,以双基地SAR成像机理和成像算法的研究为基础,分析并确定了双基地SAR成像软件的功能需求。针对软件的功能需求,对软件的总体框架作出设计,并对构成软件主体的五大功能模块:加密引导模块、输入模块、主控模块、数据处理模块和输出模块结合IDL的特点分别作出详细的设计。利用IDL的GUI设计方法和数据读入方法,给出了软件的加密引导模块、输入模块和主控模块的具体设计方案;利用本文中所研究的双基地SAR成像理论和成像算法,结合IDL的数据处理特点,改进了仿真数据的生成程序,并给出了RD算法和BP算法的数据处理流程;最后利用IDL的对象图形系统完成了软件输出模块,包括图像显示系统、图像处理系统、数据采集和分析系统及数据保存系统的设计。
最后,利用上述的设计方案,成功实现了成像软件的各个主要功能,并通过具体实例进行了展示。实现功能包括:对非移变模式下的双基地SAR利用RD算法和BP算法进行理论仿真和实测数据成像、每种算法的分步调试和结果显示、图像处理及数据采集分析。
Bistatic Synthetic Aperture Radar is a kind of new radar system, its transmitter and receiver are installed on different platforms, with the advantages of operating long range, the security, anti-interference and anti-interception, is paid more and more attention to by various countries. However, in our country, the application of bistatic SAR data, imaging processing and analysis of data visualization are still at a relatively low level. The representative of the fourth generation of visual languages IDL is utilized to develop a kind of imaging software for bistatic SAR, which can imaging and visual analysis to the data of bistatic SAR, there is a very obvious meaning to domestic bistatic SAR research and application of IDL in bistatic SAR field. The main work of this paper is as follows:
First of all, the mechanism and algorithm of imaging of bistatic SAR are correspondingly researched and analyzed, which is regarded as the base of imaging software development. In mechanism of imaging, the geometry models and the echo models of the bistatic SAR are set up under wanton flight mode at first; range history, the characteristic of Doppler and the characteristic of spatial resolution are analyzed in detail. In algorithm of imaging, the bistatic RD and BP algorithm are studied under Translationally Invariant mode, provide the principles of two kinds of algorithms, and provide two Doppler parameters estimation methods for RD algorithm: the principle of the greatest contrast and based on minimum entropy algorithm for the Discrete Fourier algorithm.
Secondly, the research on the mechanism and algorithm of bistatic imaging SAR is regarded as the foundation, the function demand of imaging software is analyzed and confirmed. Direct against the function demand for the software, the overall frame of the software is designed, and the five major function module are separately designed with combination of the characteristic of IDL, and they are Encrypt and guide module, import module, top management module , data processing module and export module. To utilize the methods of the GUI design and data input, Encrypt and guide module, import module and top management module are provided with the concrete design plan; Combining the theory and algorithm of bistatic SAR and the characteristic of data processing of IDL, the generating program of the emulation data have been improved, the data processing procedure of RD algorithm and BP algorithm is also afforded; finally the export module is finished to utilize the object graphic system of IDL, including the design of imaging display system, image process system , data acquisition and analysis system and data reservation system.
Finally, each chief function of imaging software are realized and has been shown through the concrete examples. The function realized includes: to utilize RD algorithm and BP algorithm to carry on theory emulation and imaging based on measured data under Translationally Invariant mode, debug every algorithm step by step and display results, data processing and data analysis.
引文
[1] Lorti D C, Bowman J J. Will tactical aircraft use bistatic radar. Microwave Systems News, vol.8, no.9, Sept. 1978, pp.49-52, 54.
[2] James Fawcette. Vulnerable radars seek a safe sanctuary. Microwave Systems News, vol.10, no.4, April 1980, pp.45, 47-48, 50.
[3] Robert Blumgold. Tactical bistatic radar demonstrated. Defense Electronics, vol.12, no.12, Dec. 1980, pp.78-82.
[4] Lorti D C, Balser M. Simulated performance of a tactical bistatic radar system. IEEE Electronics and Aerospace Systems Convention, EASCON, 1977, pp.4-4A to 4-40.
[5]杨振起.双(多)基地雷达系统.北京:国防工业出版社,2003.
[6] Auterman J L. Phase stability requirements for a bistatic SAR. IEEE National Radar Conference, 1984, pp.48-52.
[7] Denise M, Richard G. Bistatic radar experiment, European Conference on Synthetic Aperture Radar, 1998, pp.31-34.
[8] Caputi Jr. Image Processing for Bistatic Image Radar. US Patent,4246580, January 20,1981.
[9] Caputi Jr. Bistatic Imaging Radar Processing for Independent Transmitter and Receiver Flightpaths, US Patent,4325 065.April 13,1982.
[10] Grisham. Method of Satellite Operation Using Synthetic Aperture Radar Addition Holography for Imaging, US patent 4602 257. July 22,1986.
[11] Powell, et al. Autonomous Synchronization of a Bistatic Synthetic Aperture Radar(SAR) System. US Patent.5 113 193.May 12,1992.
[12] Cazzani L, Colesanti C, Leva D, et al. A ground-based parasitic SAR experiment. IEEE Transactions on Geoscience and Remote Sensing, vol.38, no.5, Sept. 2000, pp.2132-2141.
[13] Horne A M, Yates G. Bistatic synthetic aperture radar. IEE Radar Conference, 2002, pp.6-10.
[14] Krieger G, Fiedler H, Houman D, et al. Analysis of system concepts for bi- and multi-static SAR missions. IEEE International Geoscience and Remote Sensing Symposium, 2003, vol.2, pp.770-772.
[15]张直中,双基地合成孔径雷达.现代雷达. 2005, 17(1), pp.1-6.
[16]汤子跃,张守融.双站合成孔径雷达系统原理.北京:科学出版社, 2003.
[17] Cantalloube H, Dubois-Fernandez P, Kahhali N.. Challenges in SAR processing for airborne bistatic acquisitions, European Conference on Synthetic Aperture Radar, 2004, pp.577-580.
[18] Research System IDL Reference Guide [M]. Research System Sept 1999.
[19]李春升,燕英,陈杰.基于IDL的SAR图像处理及质量评估系统[J].通讯与电视. 2000,2,pp.49.
[20] Ray Sterner. A Description of IDL. http: // www. prl. res. in/shashi/ idl_info/ Morisset/~ description. Html. 1998.
[21] Ray Sterner. IDL6.0 Functional Summary. http: // www. rsinc. com/ idl/ IDL_Funcsum. pdf. 2003.
[22]韩培友. IDL可视化分析与应用.西安:西北工业大学出版社, 2006.
[23]阎殿武. IDL可视化工具入门与提高.北京:机械工业出版社, 2003.
[24] S.samo, Whinnery, Van Duzer, The Bistatic Radar equation for Randomly Distributed Targets, fields and waves in communication Electronics. New York: Wiley, 1965 Sec.3.12 and 3.13.
[25] Cardillo, G.P. On the use of the gradient to determine bistatic SAE resolution. In Proceedings of AP-S International Symposium, Vol.2, 1990, 1032-1035.
[26] Cherniakov, M., Zeng, T., and Plakidis, E.Ambiguity function for bistatic SAR and its application in SS-BASR performance analysis. The International Conference Radar-2003,Adelaide, Australia, 2003.
[27] Taso, T., Slamani, M., Varshney, P., Weiner., D., Schwarzlander, H. Ambiguity function for a bistatic radar. IEEE Transactions on Aerospace and Electronic systems, 33, 3 (1997), 1041-1051.
[28] Tao Zeng; Cherniakov, M.: Teng Long, Generalized approach to resolution analysis in BSAR. Aerospace and Electronic systems, IEEE Transaction on; Volume 41, Issue 2, April 2005 Page(s): 461-474.
[29]龚镇强.双基地SAR成像算法研究与实测数据处理:[硕士学位论文].电子科技大学,2008.
[30] Walterscheid I, Ender J H. Bistatic SAR processing and experiments. IEEE Trans. Geosci. Remote Sensing. 2006, 44(期): 2710-2717.
[31] Loffeld O, Nies H, Peters V, Knedlik S. Models and useful relations for bistatic SAR processing, IEEE Trans. Geosci. Remote sensing. 2004,42(期): 2031-2038.
[32] Yates G, A Horne M, Blake A P, Middleton R, and andre D B. Bistatic SAR image formation. proc. EUSAR, Ulm, Germany, May 2004, p.581-584.
[33]张振华等.双基系统的一种等效单基成像算法,中国合成孔径雷达会议, 2005.
[34]何峰.星载双/多基地SAR成像理论与信号处理研究:[博士学位论文].国防科学技术大学,2005.
[35] Rodriguez-Cassola M, Krieger G, Wendler M. Azimuth-invariant, bistatic airborne SAR processing strategies based on monostatic algorithms, IEEE International Geoscience and Remote Sensing Symposium, 2005, vol.2,pp.1047-1050.
[36] Nies H, Loffeld O, Natroshvili, et al. Parameter estimation for bistatic constellations. IEEE Internatioal Geoscience and Remote Sensing Symposium, 2005, vol.2,pp.1038-1042.
[37]刘月花等.对比度最优自聚焦算法.电子与信息学报, 2003, vol.25,no.1.
[38]于凤芹等.基于Chirp Fourier变换的LFM信号的参数估计.电子测量与仪器学报, 2003, vol.17, no.3.
[39] Xia Xiang-Gen. Discrete Chirp-Fourier Transform and its application to chip rate estimation. IEEE Trans. Signal Processing, 2000, 48(期): 3123-3133.
[40] Wang Yin-Bo, Zhang Xiao-Ling, Gong Zhen-Qiang, et al. Comparison of doppler frequency rate estimators in bistatic airborne SAR and experimental results. Asian and Pacific Conference on Synthetic Aperture Radar, Huangshan, China, 5-9 Nov., 2007, p.98-102.
[41]闫殿武. IDL与Matlab的比较[EB/OL]. http://www. Idlworld.com/ matlab.htm. 2004-4-30.
[42]杜捷. IDL5.0-第四代可视化语言的飞跃.中国图像图形学报, 1996, vol1.4, pp.349-351.
[2] James Fawcette. Vulnerable radars seek a safe sanctuary. Microwave Systems News, vol.10, no.4, April 1980, pp.45, 47-48, 50.
[3] Robert Blumgold. Tactical bistatic radar demonstrated. Defense Electronics, vol.12, no.12, Dec. 1980, pp.78-82.
[4] Lorti D C, Balser M. Simulated performance of a tactical bistatic radar system. IEEE Electronics and Aerospace Systems Convention, EASCON, 1977, pp.4-4A to 4-40.
[5]杨振起.双(多)基地雷达系统.北京:国防工业出版社,2003.
[6] Auterman J L. Phase stability requirements for a bistatic SAR. IEEE National Radar Conference, 1984, pp.48-52.
[7] Denise M, Richard G. Bistatic radar experiment, European Conference on Synthetic Aperture Radar, 1998, pp.31-34.
[8] Caputi Jr. Image Processing for Bistatic Image Radar. US Patent,4246580, January 20,1981.
[9] Caputi Jr. Bistatic Imaging Radar Processing for Independent Transmitter and Receiver Flightpaths, US Patent,4325 065.April 13,1982.
[10] Grisham. Method of Satellite Operation Using Synthetic Aperture Radar Addition Holography for Imaging, US patent 4602 257. July 22,1986.
[11] Powell, et al. Autonomous Synchronization of a Bistatic Synthetic Aperture Radar(SAR) System. US Patent.5 113 193.May 12,1992.
[12] Cazzani L, Colesanti C, Leva D, et al. A ground-based parasitic SAR experiment. IEEE Transactions on Geoscience and Remote Sensing, vol.38, no.5, Sept. 2000, pp.2132-2141.
[13] Horne A M, Yates G. Bistatic synthetic aperture radar. IEE Radar Conference, 2002, pp.6-10.
[14] Krieger G, Fiedler H, Houman D, et al. Analysis of system concepts for bi- and multi-static SAR missions. IEEE International Geoscience and Remote Sensing Symposium, 2003, vol.2, pp.770-772.
[15]张直中,双基地合成孔径雷达.现代雷达. 2005, 17(1), pp.1-6.
[16]汤子跃,张守融.双站合成孔径雷达系统原理.北京:科学出版社, 2003.
[17] Cantalloube H, Dubois-Fernandez P, Kahhali N.. Challenges in SAR processing for airborne bistatic acquisitions, European Conference on Synthetic Aperture Radar, 2004, pp.577-580.
[18] Research System IDL Reference Guide [M]. Research System Sept 1999.
[19]李春升,燕英,陈杰.基于IDL的SAR图像处理及质量评估系统[J].通讯与电视. 2000,2,pp.49.
[20] Ray Sterner. A Description of IDL. http: // www. prl. res. in/shashi/ idl_info/ Morisset/~ description. Html. 1998.
[21] Ray Sterner. IDL6.0 Functional Summary. http: // www. rsinc. com/ idl/ IDL_Funcsum. pdf. 2003.
[22]韩培友. IDL可视化分析与应用.西安:西北工业大学出版社, 2006.
[23]阎殿武. IDL可视化工具入门与提高.北京:机械工业出版社, 2003.
[24] S.samo, Whinnery, Van Duzer, The Bistatic Radar equation for Randomly Distributed Targets, fields and waves in communication Electronics. New York: Wiley, 1965 Sec.3.12 and 3.13.
[25] Cardillo, G.P. On the use of the gradient to determine bistatic SAE resolution. In Proceedings of AP-S International Symposium, Vol.2, 1990, 1032-1035.
[26] Cherniakov, M., Zeng, T., and Plakidis, E.Ambiguity function for bistatic SAR and its application in SS-BASR performance analysis. The International Conference Radar-2003,Adelaide, Australia, 2003.
[27] Taso, T., Slamani, M., Varshney, P., Weiner., D., Schwarzlander, H. Ambiguity function for a bistatic radar. IEEE Transactions on Aerospace and Electronic systems, 33, 3 (1997), 1041-1051.
[28] Tao Zeng; Cherniakov, M.: Teng Long, Generalized approach to resolution analysis in BSAR. Aerospace and Electronic systems, IEEE Transaction on; Volume 41, Issue 2, April 2005 Page(s): 461-474.
[29]龚镇强.双基地SAR成像算法研究与实测数据处理:[硕士学位论文].电子科技大学,2008.
[30] Walterscheid I, Ender J H. Bistatic SAR processing and experiments. IEEE Trans. Geosci. Remote Sensing. 2006, 44(期): 2710-2717.
[31] Loffeld O, Nies H, Peters V, Knedlik S. Models and useful relations for bistatic SAR processing, IEEE Trans. Geosci. Remote sensing. 2004,42(期): 2031-2038.
[32] Yates G, A Horne M, Blake A P, Middleton R, and andre D B. Bistatic SAR image formation. proc. EUSAR, Ulm, Germany, May 2004, p.581-584.
[33]张振华等.双基系统的一种等效单基成像算法,中国合成孔径雷达会议, 2005.
[34]何峰.星载双/多基地SAR成像理论与信号处理研究:[博士学位论文].国防科学技术大学,2005.
[35] Rodriguez-Cassola M, Krieger G, Wendler M. Azimuth-invariant, bistatic airborne SAR processing strategies based on monostatic algorithms, IEEE International Geoscience and Remote Sensing Symposium, 2005, vol.2,pp.1047-1050.
[36] Nies H, Loffeld O, Natroshvili, et al. Parameter estimation for bistatic constellations. IEEE Internatioal Geoscience and Remote Sensing Symposium, 2005, vol.2,pp.1038-1042.
[37]刘月花等.对比度最优自聚焦算法.电子与信息学报, 2003, vol.25,no.1.
[38]于凤芹等.基于Chirp Fourier变换的LFM信号的参数估计.电子测量与仪器学报, 2003, vol.17, no.3.
[39] Xia Xiang-Gen. Discrete Chirp-Fourier Transform and its application to chip rate estimation. IEEE Trans. Signal Processing, 2000, 48(期): 3123-3133.
[40] Wang Yin-Bo, Zhang Xiao-Ling, Gong Zhen-Qiang, et al. Comparison of doppler frequency rate estimators in bistatic airborne SAR and experimental results. Asian and Pacific Conference on Synthetic Aperture Radar, Huangshan, China, 5-9 Nov., 2007, p.98-102.
[41]闫殿武. IDL与Matlab的比较[EB/OL]. http://www. Idlworld.com/ matlab.htm. 2004-4-30.
[42]杜捷. IDL5.0-第四代可视化语言的飞跃.中国图像图形学报, 1996, vol1.4, pp.349-351.