本项目立足水深和水动力环境复杂多变的典型河口区-长江口区域，基于多景高空间分辨率星载合成孔径雷达（SAR）影像，采用遥感与现场观测和数值模拟相结合的方式，开展水下地形SAR遥感探测研究。针对一维雷达成像模型难以准确刻画地形-流场-雷达信号之间的相互关系，且地形对高频波段雷达信号的调制作用普遍被低估等关键科学问题，建立三维海洋数值模型与考虑波浪破碎的海面雷达成像模型，通过深入探讨模型中关键参数的选取问题，最终构建长江口浅水地形SAR成像模型。结合同步的水文与气象资料，从理论仿真与统计分析两个层面重点探讨海面风、流、潮位以及波浪破碎等动力环境要素对该海域地形雷达成像的影响。在此基础上，开发SAR浅海水深反演模型，实现对长江口水下地形信息的实时获取及地形演变的动态监测。研究成果既是对浅海地形SAR遥感成像理论的有益补充，又可为近海水域的合理开发和利用以及生态环境保护和可持续发展提供科学支撑。

The bathymetry and hydrodynamic environment of the Yangtze River Estuary is remarkably complicated and changes rapidly. The project aims to develop bathymetry assessment model from spaceborne SAR (synthetic aperture radar) by using SAR imagery, in situ measurements and numerical simulation. The 1-D radar imaging model is difficult to accurately describe the relationship between underwater topography, sea surface current and radar signals. In addition, the modulation effect of underwater topography on high frequency radar signal is generally underestimated. In view of the above questions, we will develop a 2-D SAR imaging model of shallow water topography in the Yangtze River Estuary by combing a 3-D ocean numerical model and sea surface radar imaging model considering the effect of wave breaking. Then using over a hundred of SAR images and synchronous hydrodynamic and meteorological data, we will theoretically and statistically investigate the influence of ocean current, sea surface wind, tidal elevation and wave breaking on SAR imaging capability. Base on the above analysis, a bathymetry assessment model will be developed to estimate water depth from SAR imagery. The results will not only complement the existing theory of SAR imaging of shallow water topography, but provide technical supports on offshore resource exploration and sustainable development of local environment.