状态空间法在超宽带雷达动目标速度及距离像估计中的应用

摘要

This paper estimates high-resolution radial velocity and range profile of moving target for Ultra-WideBand (UWB) radar via State-Space (SS) method. First, an impulse response of scatterers in frequency domain is obtained by utilizing the echo with stretching in UWB radar to get the Hankel matrix used in SS method. Second, through SS, the radial velocity and range profile of target moving at high speed are estimated for UWB radar. The corresponding Cramer-Rao Lower Bound (CRLB) is further derived. This method is not only can estimate the high resolution range profile of the target, but also can avoid the variation of Doppler with the frequency in the bandwidth of signal, i.e., the influence of Doppler dispersion on radial velocity estimates. Also, this method has fine noise-rejection ability. Besides, due to only acquiring the impulse response in frequency domain and no considering the special waveform, the method there is not the restriction of the transmitted waveform, which is greatly different with wavelet transform. The simulation results corroborate the feasibility and effectivity of this method.%该文通过状态空间(State-Space,SS)法高分辨估计超宽带(Ultra-Wide Band,UWB)雷达运动目标径向速度及其距离像.首先,结合具有伸缩的UWB雷达回波模型获得散射体频域冲激响应,以构建SS所需的Hankel矩阵.其次,利用SS估计UWB雷达高速运动目标径向速度及距离像.进一步,分别推导了上述估计参数的克拉美一罗下界(Cramér-Rao Lower Bound,CRLB).SS法不但能获得目标高分辨距离像,而且较好地规避了多普勒随信号带宽内频率变化,即多普勒色散对径向速度估计的影响.该方法亦具有良好的噪声抑制能力.此外,其只需目标频域冲激响应,并未涉及具体发射波形,因此未受发射信号形式的限制,这不同于利用小波变换估计相关参数的方法.仿真实验验证了该方法的可行及有效性.