摘要
X波段岸基雷达作为一种新颖的海况遥感观测方式,可直接观测到实时的海况信息。通过对雷达影像的分析,能够获得海面上的波浪场。由于波浪在近岸的折射、浅化变形等原因,观测到的雷达影像场为近岸非均匀波浪场,在一定程度上限制了传统影像分析方法——傅里叶变换的应用。针对波浪的近岸非均匀性,将二维小波变换应用于雷达影像分析,子影像中6个空间点的波数谱显示:影像中的波浪非均匀性显著,主能量的波数呈现明显的增加趋势。二维小波变换应用到X波段雷达近岸影像处理中,可较好体现近岸波浪的非均匀性。
In the application of remote sensing, X-band land-based radar is an appropriate technique in monitoring sea states, and wave field can be obtained from radar images. Fourier transform (FT) is the common algorithm in processing of investigating wave information from radar images, which makes one assumption that the wave field within radar images should be spatially homogeneous. However, nearshore wave field within radar images is non-homogeneous, resulting in ambiguity of wave characteristics by averaging the information of wave refraction and shoaling. The paper implemented the two-dimensional wavelet transform (2-D WT) to the analysis of radar image. Spatial spectrum distinguished at six different space locations showed obvious non-homogeneity, which demonstrated 2-D WT owning the encouraging ability of analyzing near,shore wave field from radar images.
出处
《海洋工程》
CSCD
北大核心
2010年第1期104-109,共6页
The Ocean Engineering
基金
水文水资源与水利工程科学国家重点实验室开放基金资助项目(2008491011)
江苏省普通高校研究生科研创新计划资助项目(CX09B165Z)
关键词
X波段雷达
近岸影像
波谱
二维小波变换
X-band radar
nearshore wave image
wave spectrum
two-dlmensional wavelet transform