杂波谱中心Doppler频率和谱宽的快速估计算法

为了能有效地抑制机载下视雷达的地杂波 ,需要对这类杂波的中心 Doppler频率和谱宽进行精确地估计。基于快速傅里叶变换 (FFT)运算和质量中心的概念 ,提出一种快速的高性能估计算法 ,称为质量中心法。该算法直接在频域上对杂波谱参数进行估计 ,具有算法简单 ,易于实现的优点。为了对比它与传统的熵谱估计法以及相关函数法之间的性能 ,给出仿真计算实例。结果表明 ,质量中心法的运算量远小于熵谱估计法 ,但是二者的性能却相差不多 ,尤其是对谱中心的估计。与同样具有小运算量的相关函数法相比 ,在谱宽估计性能上 ,质量中心法更具优势。由于采用短数据即可得到良好的估计性能 ,因此该算法适用于短时平稳的数据

Fast method for estimating center Doppler frequency and bandwidth of clutter spectrum

In order to suppress the ground clutter in down scan airborne radar, the center Doppler frequency and the bandwidth of the clutter spectrum must be estimated precisely. The FFT (fast fourier transform) algorithm and the mass center notion were used to develop a fast estimation algorithm named the Mass Center Method (MCM). The algorithm directly estimates the clutter spectral parameters in the frequency domain and has such advantages as simplicity and easy implementation. Simulation examples compare the performance of the MCM with that of the spectral estimation method or the autocorrelation method. The simulation results demonstrate that the computational complexity of the MCM is much less than that of the spectral estimation method, but they have nearly the same estimation performance, especially when estimating center frequency. The MCM has much better bandwidth estimation performance than the autocorrelation method, whose computational burden is also light. Because its estimation performance is very good with short data sequences, the MCM can be applied to short time stationary data.