基于分数阶傅里叶变换的加速微弱目标检测与估计

FRFT based detection and estimation of accelerating weak target

加速微弱目标使雷达回波多普勒谱严重扩展,传统动目标检测方法失效.为了实现监视雷达对加速微弱目标的有效检测和参数估计,提出了一种新的雷达信号处理方法.利用分数阶傅里叶变换完成监视雷达接收回波慢时间域线性调频信号的能量集聚,提高低信噪比条件下的加速目标检测性能,并通过离散尺度化法对加速目标参数进行估计.理论推导和仿真分析了相参处理间隔长度、分数阶次步长和信噪比等因素对所提方法的统计检测性能和参数估计精度的影响.

The acceleration of weak target leads to great spread of Doppler spectrum of the echo and traditional detection methods do not work.To solve the problem,a novel method with surveillance radar is proposed which can detect and estimate the parameters of the accelerating targets effectively.First the energy of chirp signal in slow time domain of the echo is integrated by the fractional Fourier transform to improve the detection performance in low signal to noise ratio（SNR）condition.Then the target parameters are estimated by discrete scaling transform method.Finally,the effect of different factors such as coherent processing interval,fractional step and SNR on detection performance and parameter estimation precision of the proposed method are analyzed by theoretical derivation and simulated experiments.