摘要
俯仰向数字波束形成(DBF)是实现高分辨率宽测绘带星载SAR系统的关键技术。该技术可以生成能够灵活控制的高增益窄波束用于回波信号的接收,从而提升SAR系统性能。该文在研究俯仰向DBF技术应用于宽测绘带SAR系统的基础上,重点分析了俯仰向DBF技术对系统性能指标的影响,推导了基于俯仰向DBF技术的系统等效后向散射系数(NESZ)和距离模糊比(RASR)的表达式,并且将阵列信号处理中的零点指向技术应用于SAR,使得系统在接收目标信号的同时抑制模糊区方向的回波,显著地提高了系统的距离模糊指标。仿真结果表明,俯仰向DBF-SAR系统的性能相对于传统单通道系统具有明显的优势。
Digital Beam Forming (DBF) in elevation is regarded as an important candidate for high resolution and wide coverage imaging SAR system, since it can enhance the performance of SAR system by forming a high gain and sharp beam pattern to receive the pulse echoes. This paper is based on range DBF for wide-swath SAR system, and analyzes particularly on performance of SAR system affected by DBF in elevation. The expressions of Noise Equivalent Sigma Zero (NESZ) and Range Ambiguity to Signal Ratio (RASR) for the range DBF-SAR system are derived in detail. In order to suppress the range ambiguity energy, the null-steering technology is introduced. All the simulation results validate the advantages of range DBF-SAR system compared with the conventional single channel system.
出处
《电子与信息学报》
EI
CSCD
北大核心
2014年第11期2711-2716,共6页
Journal of Electronics & Information Technology
关键词
合成孔径雷达
数字波束形成
零点指向
等效后向散射系数
距离模糊比
SAR
Digital Beam-Forming (DBF)
Null steering
Noise Equivalent Sigma Zero (NESZ)
RangeAmbiguity to Signal Ratio (RASR)