数字电视外辐射源雷达目标徙动补偿新方法

A Novel Migration Compensation Algorithm for Passive Radar using Digital TV Signals

增加相参积累时间是提高数字电视外辐射源雷达探测能力的一种较为常见的技术,但当目标速度和加速度较大时,长时间相参积累会使目标回波面临距离徙动和多普勒徙动,且当外辐射源雷达信号在慢时域为非均匀采样(如中国移动多媒体广播信号)时,广泛采用的如Keystone变换和Radon-Fourier变换等徙动补偿算法已不能很好地适用。该文研究了一种基于两次短傅里叶变换的徙动补偿算法,可同时适用于非均匀和均匀采样信号,并在此基础上提出一种修正算法,修正后的该算法能检测具有更大速度和加速度的目标,同时用于均匀采样时,相对已有一些算法其运算量更小。文中首先分析了非均匀采样信号的特殊性及该特殊性带来的新困难,接着基于该特殊信号的多普勒处理阐述了徙动机理与该徙动补偿算法的基本原理。仿真和实测数据处理证明了该算法的有效性。

Increasing integration time is a main approach to improve performance of passive radar, but the range and Doppler migration may occur for high-speed and accelerated targets, and for non-uniform sampled signal in the slow time such as China mobile multimedia broadcasting signal, the most used migration compensation algorithms such as Keystone transform and Radon-Fourier transform are inapplicable. This paper uses a long-time coherent integration algorithm based on two-step Doppler processing, which can be applied to both the uniform and non-uniform sampled signal, a modified algorithm based on this method is proposed, which can detect higher speed-acceleration targets, and this algorithm can improve computation efficiency. The specialty and difficulty of non-uniform sampled signal are analyzed first, then on the basis of Doppler processing of certain signal, migration reason and migration compensation principle are demonstrated. Finally, simulation and real data processing confirm the effectiveness of the proposed method.