针对非合作目标的调频步进编码波形设计方法

Design method of coded stepped frequency chirp waveform for non-cooperative target

雷达对于非合作目标的探测,存在目标微小与速度未知两大困难,而相干积累的方法需要准确探测目标速度,并进行速度补偿,实际应用过程中效果受限。针对此问题提出了一种调频步进编码波形设计方法,可以在速度未知情况下脉间积累,同时在准确测量速度后宽带合成。首先研究线性调频子脉冲的距离速度耦合特性,通过波形设计抵消脉间目标运动成像位置变化;然后研究调频步进编码波形的宽带合成技术,使所得的高分辨一维距离像无距离混叠。最后,数值仿真实验验证了所提出波形的优势与应用价值。

There are two typical difficulties in radar detection of uncooperative targets:weak target and unknown velocity.Coherent pulse integration method is used in detecting the weak target,but it needs to detect the target velocity accurately and compensate the velocity,therefore it is limited in practical application.A design method of coded stepped frequency chirp waveform is proposed,which can integrate the pulse when the velocity is unknown and synthesize the wideband after the velocity is measured accurately.Firstly,the range velocity coupling characteristic of Linear Frequency Modulation(LFM)is studied,and the range migration is compensated by waveform parameter design.Then,the wideband synthetic technology of the stepped frequency chirp waveform is studied in order to get high resolution range profile without range ambiguity.Finally,simulation experiments validate the advantages and practical value of the proposed waveform.