合成孔径雷达（SAR)目标成像仿真，结合PCA的尺度不变特征变换(SIFT)算法，旋转机械二维全息谱计算。- Synthetic Aperture Radar (SAR) imaging simulation target, Combined with PCA scale invariant feature transform (SIFT) algorithm, Rotating machinery 2-d holographic spectrum calculation.