多通道合成孔径雷达（SAR）空时自适应处理是抑制地面杂波的有效方法，而空时二维滤波器的权值求取离不开杂波协方差矩阵的估计。从多通道SAR回波模型出发，提出了一种基于二维FFT的多通道SAR原始数据频域模拟方法，并根据该方法模拟出的多通道数据对空时二维协方差矩阵进行了估计。仿真结果显示,该方法在有效降低运算量的情况下保持了数据的真实性，良好地反映了多通道SAR的空时二维杂波特性。

Space-time adaptive processing (STAP) is an effective method to suppress ground clutter and extract moving targets in the Multi-Channel SAR (MSAR) system. The space-time two-dimensional filter weight is decided by the evaluation of the clutter covariance matrix. From the MSAR echoes model, a method of raw-data simulation in the frequency domain by two-dimensional FFT is proposed and the evaluating of MSAR clutter space-time covariance matrix is made. The simulation result shows that the data produced by this method retain the reality of MSAR space-time clutter characteristic with lower computational complexity.