摘要
针对传统合成孔径声呐成像算法在大斜视条件下存在多普勒频移导致成像效果下降的局限性,提出在回波信号距离向去斜的同时去除其中心频率,保证了Keystone变换的有效性;并在方位向处理上引入圆模型重新构建点目标中心斜距的方位关系。仿真结果表明,在斜视条件下,所提圆模型和NLCS算法可以使边缘点获得更好聚焦效果。
In traditional synthetic aperture sonar imaging algorithms,the Doppler shift in high squint usually leads to the deterioration of the imaging results.To solve this issue,a method in range processing is proposed to remove the center frequency in the deramp-operation,which guarantees the effectiveness of keystone transform(KT).A circle model is introduced in azimuth processing to reconstruct the azimuth relationship of center slant ranges of different targets.Simulation results show that the proposed circle model and nonlinear chirp scaling(NLCS)algorithm can obtain better focusing effect of edge points in high squint.
作者
杨樊
钟华
常宇亮
章坚武
YANG Fan;ZHONG Hua;CHANG Yuliang;ZHANG Jianwu(Schoolof Communication Engineering,Hangzhou Dianzi University,Hangzhou Zhejiang 310018,China)
出处
《杭州电子科技大学学报(自然科学版)》
2018年第4期30-34,69,共6页
Journal of Hangzhou Dianzi University:Natural Sciences
基金
国家自然科学基金资助项目(61301248
61501478)
中国航天科技创新基金资助项目(20140795003)
关键词
合成孔径声呐
NLCS算法
大斜视
多普勒频移
圆模型
synthetic aperture sonar
nonlinear chirp scaling algorithm
hi ghl y squi nt
Doppl er shift
circle model