利用运动目标线谱的多普勒频移特性估计目标参数,需要精确提取出多普勒频移曲线。针对舰船辐射线谱噪声多普勒频移曲线提取的短时傅里叶变换(Short Time Fourier Transform,STFT)方法存在分辨率门限的问题,提出了一种利用子空间旋转不变技术(ESPRIT)高分辨频率估计法与STFT相结合的方法,提高了频率估计的精度和分辨率,可很精确地提取出频率间隔较近的多普勒频移曲线,而且计算量较小。计算机仿真和水池实验验证了该方法的有效性。
Parameter estimation of moving target by using Doppler shift needs to extract Doppler shift curves accu-rately from the ship-radiated line component spectrum.A new Doppler shift estimation method combining ESPRIT and Short Time Fourier Transform(STFT) is proposed in this paper to overcome the frequency resolution limitation of STFT.This method improves accuracy and resolution of frequency estimation.It can extract Doppler shift curves accu-rately with less computation burden for small interval of several line components.Numerical simulations and experi-ments in anechoic tank showed the validity of the proposed method.