In this model, the filed is divided into many enough small grids.So we can consider one grid as a linear spatial filter (LSF), and regard the supersonic flows as the combination of many LSFs.

• 模型中划分的网格足够小，可认为一个网格单元是一个线性滤波器，最终将网格化的高速流场看作为由多个线性空间滤波器组成的一个空间滤波器。