摘要
星弹双基前视SAR能够全天时全天候获取导弹前方区域高分辨图像,是一种极具潜力的成像制导技术。然而,距离和方位参数的耦合与空变,阻碍着星弹双基前视SAR向高分辨成像发展。该文首先基于低轨星载照射源与高速前视的弹载接收平台构型,推导了回波信号的精确距离多普勒域解析式。然后,在距离向上,提出距离非线性变标(NCS)算法来均衡距离徙动和距离调频率,并在二维频域一致补偿;在方位向上,该文所提算法将收发机的方位调频率进行分解,利用方位NCS消除方位调频率在方位向上的高阶空变。最后,进行二维匹配滤波,得到全局聚焦良好的SAR图像。点目标和场景仿真验证了所提算法的有效性。
The spaceborne-missile bistatic forward-looking Synthetic Aperture Radar(SAR)is a promising imaging guidance technology that can obtain high-resolution images of the area in front of the missile all day and in all weather types.However,the coupling and spatial variations in range and azimuth parameters hinder the development of high-resolution spaceborne-missile bistatic forward-looking SAR imaging.In this study,the accurate-range Doppler domain analytical formula for echo signals was derived based on the low-orbit spaceborne illuminator and high-speed forward-looking missile-borne receiving platform configuration.Subsequently,in range processing,a range Nonlinear Chirp Scaling(NCS)was proposed to equalize the range cell migration and range Frequency Modulation(FM)rate,and both can be uniformly compensated in the two-dimensional frequency domain.In azimuth processing,the proposed method decomposed the azimuth FM rates of the transmitter and receiver.Then,the azimuth NCS was used to eliminate the high-order spatial variation of the azimuth FM rate.Finally,a two-dimensional matched filtering was performed to obtain a SAR image with a good global focus.The point and scene simulation verify the effectiveness of the proposed algorithm.
作者
刘裕洲
蔡天倚
李亚超
宋炫
王选琪
安培赟
LIU Yuzhou;CAI Tianyi;LI Yachao;SONG Xuan;WANG Xuanqi;AN Peiyun(National Key Laboratory of Radar Signal Processing,Xidian University,Xi’an 710071,China;Beijing Institute of Remote-Sensing Equipment,Beijing 100039,China)
出处
《雷达学报（中英文）》
EI
CSCD
北大核心
2023年第6期1202-1214,共13页
Journal of Radars
基金
国家重点研发计划(2018YFB2202500)
国家自然科学基金(62171337,62101396)
陕西省重点研发计划(2017KW-ZD-12)
陕西省杰出青年基金(S2020-JC-JQ-0056)
中央高校基本科研基金(XJS212205)
西安电子科技大学研究生创新基金(YJSJ23016)。
关键词
星弹双基前视SAR
距离徙动
方位调频率
非线性变标
空变性
Spaceborne-missile bistatic forward-looking SAR
Range Cell Migration(RCM)
Azimuth FM rate
Nonlinear Chirp Scaling(NCS)
Spatial variation
