真实孔径雷达海洋图像的分形特征分析  

Fractal analysis of real aperture radar ocean image

作　　者：晏磊[1] 罗立[1] 张雪虎[1] 

机构地区：[1]北京大学遥感与地理信息系统研究所

出　　处：《电波科学学报》2007年第4期604-609,645,共7页Chinese Journal of Radio Science

摘　　要：结合海洋雷达图像的电磁散射机理,采用小波分析方法对真实孔径雷达海洋图像的分形维数和特征进行分析,发现虽然海洋表面波具有分形的特征,但是海洋雷达图像在布拉格散射机制主导的情况下,不具备分形特征。为了准确计算雷达图像的分形维数,还对差分盒计数法、数学形态学方法和小波分析方法三种分形维数的计算方法进行了评估,通过对已知维数的模拟图像进行分形维数的计算,分析了三种方法的优缺点。Three methods for fractal dimension analysis are applied to airborne real aperture radar ocean images to study the fractal characteristics of the ocean radar backscatter. It is found that although the sea surface has fractal properties, its xband radar image exhibits no fractal characteristics when the dominating scattering mechanism is Bragg scattering. The result is discussed within the context of scattering mechanisms dominating radar echoes under these conditions. To compute the fractal dimension of the radar image correctly, differential box-counting approach, morphological method and wavelet variance method are evaluated and compared by analyzing simulated gray images with known fractal dimensions.

关 键 词：真实孔径雷达 雷达海洋图像 分形维数 小波分析方法 布拉格散射 

分 类 号：TP753[自动化与计算机技术—检测技术与自动化装置]