基于共轭噪声组的宽带噪声雷达机动目标参数估计

Parameter Estimation of Maneuvering Targets in Wideband Noise Radar Based on Conjugate Noise Group

宽带噪声雷达参数估计时通常会采用宽带互模糊函数的方法,但是在处理机动目标时这种方法需要在距离、速度及加速度3维搜索而导致运算量巨大,为此该文提出一种基于共轭噪声组的机动目标参数估计算法。该算法首先根据回波伸缩效应预设多路通道,每路通道截取固定长度的噪声组内信号进行混频,然后利用分数阶傅里叶变换(Fr FT)估计混频信号的多普勒相位,根据相位信息构造补偿函数,并对补偿后的噪声组信号利用频域尺度相关(FSC)算法估计回波的时延,最后联立多普勒相位及时延信息获取目标的距离、速度和加速度。该算法避免了目标参数3维搜索的过程,无需时域重构回波信号,较宽带互模糊函数方法极大地降低了运算量,整个算法都可通过快速傅里叶变换(FFT)实现,便于系统实时处理。仿真结果验证了该算法的有效性及优势。

he wideband cross-ambiguity function method is commonly adopted to execute the parameter estimation of wideband noise radar, but it needs three-dimensional search in distance, velocity and acceleration when dealing with maneuvering targets, which takes huge computation burden. A novel method based on the conjugate noise group is proposed for addressing the problem of parameter estimation of maneuvering targets. Firstly, the multiple channel is set up according to the echo stretching effect, and the internal signals of the noise group is cut out in fixed length for mixing in each channel. Then the Doppler phase is estimated with the mixed signal by Fractional Fourier Transform（Fr FT）. The Phase compensation function is constructed by the Doppler phase and the delay is estimated by Frequency-domain Scale Correlation（FSC） algorithm with the compensated noise group signal. Finally, the range, velocity and acceleration are obtained by the two simultaneous equations of the Doppler phase and delay. The proposed method avoids three-dimensional search and reconstruction of the echo signal in time domain, which reduces a large amount of computation compared to the wideband cross-ambiguity function method. The method is feasible for real time processing as the whole algorithm can be accomplished by Fast Fourier Transform（FFT）. The effectiveness and superiority of the proposed method are demonstrated by the simulation results.