摘要
针对分布式小卫星雷达系统的地面低速运动目标检测,本文给出了一种新的基于多发射正交编码信号的单接收GMTI处理系统体制,详细分析了该系统对多发射正交编码波形的性能要求,并基于此给出了相应的正交波形优化设计方法.在这种新的系统体制中,采用不同卫星分别发射优化后的正交波形,在接收卫星上将回波信号分别和各个发射信号匹配得到不同发射卫星所对应的图像,然后利用基于图象域的多通道、多像素二维联合自适应处理进行地面低速运动目标检测,这样避免了多颗卫星之间的数据传送,提高了整个系统的实时处理性能.采用的正交波形优化设计方法以接收回波信号中匹配出各发射卫星的一维像性能为优化准则,即利用一维像的主瓣形状和旁瓣性能的约束来实现.波形正交性、算法收敛性、杂波相消以及动目标检测方面的仿真结果和性能分析验证了该系统以及相应算法的可行性和有效性.
By exploiting multiple transmissions of orthogonal coding signal and single reception,a new GMTI processing scheme for ground moving targets detection with low velocity in space-borne multiple input and single output(MISO) radar systems is presented in the paper.Firstly,the requirements of multiple orthogonal coding waveform for the MISO radar system is analysed in detail.Focusing on this new scheme,an orthogonal waveform optimization design method is also proposed.In this GMTI processing scheme,different satellites independently transmit the optimized orthogonal waveform and one of the transmission satellites acts as the receiver and matches the received echo signal with each of the transmission signal,respectively.Detection of ground moving targets with low velocity can be achieved by joint adaptive two-dimension processing of multi-channel and multi-pixel on image domain. In this way,data communications among multiple satellites is not necessary and hence real time processing capability of the whole system can be improved. The performance of one-dimension image after matching by the receiving satellite,i, e. the shape of its mainlobe and the performance of its sidelobe is considered as the optimization criteria in the proposed waveform design method. Simulations and analysis are performed to testify the feasibility and effectiveness of the proposed system and waveform design method,in terms of the orthogonality of waveform, convergence of the design algorithm, clutter cancellation, and detection performance of targets.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2009年第12期2803-2809,共7页
Acta Electronica Sinica
基金
973课题和国家自然科学基金(No.60472097
60971108)