Wavenumber-domain Imaging Algorithm for High Squint SAR Based on Azimuth Variation Range Model
DONG Qi①② YANG Zemin③ LI Zhenyu①② SUN Guangcai①② XING Mengdao①②
①(National Laboratory of Radar Signal Processing, Xidian University, Xi'an 710071, China) ②(Collaborative Innovation Center of Information Sensing and Understand, Xidian University, Xi'an 710071, China) ③(The 29th Researth Institute of China Electronics Technology Group Corporation, Chengdu 610036, China)
Due to the acceleration in the moving of the platform, the SAR imaging of highly squinted maneuvering platform becomes a problem to be solved urgently. The majority of currently existing range models fail in taking the azimuth-variation into consideration, so the well-focused images are not obtained. To solve these problems, a new azimuth-variation range model under the non-linear trajectory caused by acceleration is constructed. Based on this model, a wavenumber-domain imaging algorithm for high squint SAR is proposed, which takes advantage of the azimuth-variation filter to remove the azimuth chirp rate changes and Doppler center changes caused by the acceleration. By the analysis of the model error, the precision of the model is confirmed. Contrast simulation results are presented to valid the superiority of the proposed approach.
董祺,杨泽民,李震宇,孙光才,邢孟道. 基于方位空变斜距模型的大斜视机动平台波数域SAR成像算法[J]. 电子与信息学报, 2016, 38(12): 3166-3173.
DONG Qi, YANG Zemin, LI Zhenyu, SUN Guangcai, XING Mengdao. Wavenumber-domain Imaging Algorithm for High Squint SAR Based on Azimuth Variation Range Model. JEIT, 2016, 38(12): 3166-3173.
ZHANG Lei, SHENG Jialian, XING Mengdao, et al. Wavenumber-domain autofocusing for highly squinted UAV SAR imagery[J]. IEEE Sensors Journal, 2012, 12(5): 1574-1588. doi: 10.1109/JSEN.2011.2175216.
[2]
ZHANG Lei, QIAO Zhijun, XING Mengdao, et al. A robust motion compensation approach for UAV SAR imagery[J]. IEEE Transactions on Geoscience and Remote Sensing, 2012, 50(8): 3202-3218. doi: 10.1109/TGRS.2011.2180392.
LI Zhenyu, LIANG Yi, XING Mengdao, et al. New subaperture imaging algorithm and geometric correction method for high squint diving SAR based on equivalent squint model[J]. Journal of Electronics & Information Technology, 2015, 37(8): 1814-1820. doi: 10.11999/ JEIT141516.
LI Zhenyu, LIANG Yi, XING Mengdao, et al. A frequency phase filtering imaging algorithm for high squint SAR in diving movement[J]. Acta Electronica Sinica, 2015, 43(10): 2014-2021. doi: 10.3969/j.issn.0372-2112.2015.10.020.
[5]
XIAO Jing and HU Xuecheng. A modified RD algorithm for airborne high squint mode SAR imaging[C]. IEEE 1st Asian and Pacific Conference on Synthetic Aperture Radar, Huangshan, China, 2007: 444-448. doi: 10.1109/APSAR. 2007.4418646.
ZHOU Song, ZHOU Peng, LI Yachao, et al. Research on the imaging algorithm for missile-borne SAR with downward movement[J]. Journal of Xidian University(Natural Science), 2011, 38(3): 90-98.
[7]
CHEN Si, ZHANG Shuning, ZHAO Huichang, et al. A new Chirp scaling algorithm for highly squinted missile-borne SAR based on FrFT[J]. IEEE Journal of Selected Topics in Applied Earth Observations & Remote Sensing, 2015, 8(8): 3977-3987. doi: 10.1109/JSTARS.2014.2360192.
ZHOU Peng, ZHOU Song, XIONG Tao, et al. A Chirp-Z imaging algorithm for missile-borne SAR with diving maneuver based on the method of series reversion[J]. Journal of Electronics & Information Technology, 2010, 32(12): 2861-2867. doi: 10.3724/SP.J.1146.2010.00452.
ZHOU Song, BAO Min, ZHOU Peng, et al. Imaging algorithm for missile-borne SAR with downward movement based on azimuth nonlinear chirp scaling[J]. Journal of Electronics & Information Technology, 2011, 33(6): 1420-1426. doi: 10.3724/SP.J.1146.2010.01124.
[10]
LI Zhenyu and XING Mengdao. A frequency-domain imaging algorithm for highly squinted SAR mounted on maneuvering platforms with nonlinear trajectory[J]. IEEE Transactions on Geoscience and Remote Sensing, 2016, 54(7): 4023-4038. doi: 10.1109/TGRS.2016.2535391.
[11]
DAVID C, MUNSON J R, JENKINS W K, et al. A tomographic formulation of spotlight mode synthetic aperture radar[J]. Proceedings of the IEEE, 1983, 72(8): 917-925. doi: 10.1109/PROC.1983.12698.
[12]
YEGULALP A F. Fast back-projection algorithm for synthetic aperture radar[C]. The Record of the 1999 IEEE Radar Conference, Waltham, MA, USA, 1999: 60-65.
[13]
ULANDER L M H, HELLSTEN H, and STENSTROM G. Synthetic-aperture radar processing using fast factorized back-projection[J]. IEEE Transactions on Aerospace and Electronic Systems, 2003, 39(3): 760-776. doi: 10.1109/TAES. 2003.1238734.
[14]
REIGBER A, ALIVIZATOS E, POTSIS A, et al. Extended wavenumber-domain synthetic aperture radar focusing with integrated motion compensation[J]. IEE Proceedings-Radar, Sonar and Navigation, 2006, 153(3): 301-310. doi: 10.1049/ ip-rsn:20045087.
[15]
WU Yong, SONG Hongjun, SHANG Xiuqin, et al. Improved RMA based on nonuniform fast Fourier transforms[C]. 9th International Conference on Signal Processing, Beijing, China, 2008: 2489-2492. doi: 10.1109/ICOSP.2008.4697654.
[16]
LI Zhe, WANG Jian, and LIU Qinghuo. Interpolation-free Stolt mapping for SAR imaging[J]. IEEE Geoscience and Remote Sensing Letters, 2014, 11(5): 926-930. doi: 10.1109/ LGRS.2013.2281847.
[17]
LI Zhenyu, LIANG Yi, XING Mengdao, et al. An improved range model and omega-K-based imaging algorithm for high- squint SAR with curved trajectory and constant acceleration [J]. IEEE Geoscience and Remote Sensing Letters, 2016, 13(5): 656-660. doi: 10.1109/LGRS.2016.2533631.
[18]
TANG Shiyang, ZHANG Linrang, GUO Ping, et al. Acceleration model analyses and imaging algorithm for highly squinted airborne spotlight-mode SAR with maneuvers[J]. IEEE Journal of Selected Topics in Applied Earth Observations & Remote Sensing, 2015, 8(3): 1120-1131. doi: 10.1109/JSTARS.2015.2399103.
[19]
TANG Shiyang, ZHANG Linrang, GUO Ping, et al. An omega-K algorithm for highly squinted missile-borne SAR with constant acceleration[J]. IEEE Geoscience and Remote Sensing Letters, 2014, 11(9): 1569-1573. doi: 10.1109/LGRS. 2014.2301718.
