机载合成孔径雷达图像频谱分析技术地质应用评价

频谱分析是空间滤波的一种。本文使用光学傅里叶变换分析SAR图像的空间频率特征。从取得的功率谱与功率谱角分布数据中可以:(1)确定与雷达后向散射方向有关面的走向最大(最小)方位角;(2)分析频谱曲线两个峰的夹角及其地学意义;(3)推算其水系密度;(4)研究样区地形基本特征。 这些资料有助于研究线性构造区域展布特征,岩类识别和地貌分类等。

Application of Optical Power Spectrum Analysis in Assessment Geologic Utility on SAR Image

Fifteen samples have been continuously sampled in the E-W direction of the Yueyang experiment area (35 square kilometers). These samples were collected from a wide range of different rock patterns such as river-lake sediment(Q), fragmental rock(K), sand slate(Pt) and granite. Analysis of optical power spectrum has been applied to obtain the power spectrum curve and power spectrum distribution curve, which is helpful for:1. obtain the strike of reflectance planes which will correspondingly have maximum values of back scatter. These planes are usually terrain slopes fact, outcrop surface, and structural fracture planes.2. The angle included between the direction of the maximum values can well reflect the angle made by the confluencing branchravine.3. calculate the drainage system density.4. analysis the general feature of topography in the sample area. The general feature of topography has close relationship with the characteristic of the lithologic association.We can determine the predominant direction and concentration density of lineament, and discriminate some types of rock in the studied area by spectrum analysis.