基于扩频方法的谐波雷达目标检测研究

Research on Target Detection of Harmonic Radar Based on a Spread Spectrum Method

针对谐波雷达探测非线性目标物,存在抗干扰能力差,虚警率高等问题,设计了一种基于扩频方法的谐波雷达收发系统。在发射端采用直接扩频的方法扩展信号的频谱,提高雷达信号的抗干扰能力。在接收端采用降采样滑动相关检测技术检测接收到的信号,完成对二次谐波信号的检测。相较于常规的滑动检测方法,当接收端抽取因子为4时,采用降采样滑动相关检测的计算量约为常规滑动检测方法的1/38,有效减少了系统的计算量。利用FPGA验证表明,雷达发射端合理有效,而接收机经过约50μs能检测到反射回的二次谐波信号。

Harmonic radar has poor anti-interference ability and high false alarm rate when it detects nonlinear targets.In this paper,a harmonic radar transceiver system based on a spread spectrum method is proposed.At the transmitter end,the direct spread spectrum method is used to expand the spectrum of the signals and improve the anti-interference ability of the radar signals.At the receiver end,the down-sampling sliding correlation detection technology is used to detect the received signals and complete the detection of the second harmonic signals.When the extraction factor of the receiver is 4,the calculation amount of the down-sampling sliding correlation detection method is about 1/38 of that of the conventional sliding detection method.The sliding detection method employed in this paper effectively reduces the calculation amount of the system.Results of the FPGA-based test show that the radar transmitter is effective and the receiver can detect the reflected second harmonic signals after about 50μs.