自相关分析和频谱分析是DSP的基本内容。本文档通过对太阳黑子活动周期的实例分析，说明自相关分析和频谱分析的重要作用和实际应用方法。-Autocorrelation analysis and spectrum analysis is the basic content of DSP. This document by sunspot activity cycle case study shows the important role and the practical application of

Synthetic Aperture Radar (SAR) imaging simulation target, Calculation crosshairs diffraction image at different distances, Spectral methods of computational fluid dynamics flow of some of the overall stability of the phenomenon.