导航X波段雷达非均匀浪流场反演及自主定标理论基础研究

项目名称： 导航X波段雷达非均匀浪流场反演及自主定标理论基础研究

项目编号： No.41506199

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 陈忠彪

作者单位： 南京信息工程大学

项目金额： 21万元

中文摘要： 导航X波段雷达在近岸海洋环境观测中有广泛的应用前景，由于近岸区域海浪的非线性性强，传统的基于线性海浪理论的傅里叶谱分析方法不适用。本项目研究X波段雷达对近岸海表面成像时的电磁散射特性，建立适用于近岸非均匀海区的浪流场反演和自主定标算法。. 第一，用数值海浪模式模拟近岸的非均匀波浪场，用电磁散射理论求解掠入射条件下海面的电磁散射回波，理论研究影响X波段雷达对非均匀海面成像的调制机制，再结合利用相参X波段雷达同步观测的海浪谱，建立适用于近岸海区不同位置的调制传递函数，进而反演整个观测海区的波浪场和流场。第二，利用非正态随机海浪理论建立适用于非各向同性海面的阴影分布函数，利用经验正交函数提取雷达图像中的海浪阴影，再结合几何光学理论建立海浪波高的自动定标算法；第三，研究降雨对X波段雷达图像的影响，提出消除雨杂波的方法。通过以上研究，为X波段雷达应用于近岸海洋环境监测提供依据。

中文关键词： 导航X波段雷达；近岸；海浪；海流；反演算法

英文摘要： X-band marine radar has wide application prospect in the monitoring of nearshore environment. Due to the strong nonlinearity of nearshore ocean waves, conventional Fourier spectral analysis algorithms which based on the linear ocean wave theory are not suitable to be used in the retrieval of nearshore ocean waves and currents. This program aims to study the backscatter characteristics of X-band marine radar when imaging nearshore ocean waves, and propose applicable retrieval algorithms for nearshore ocean wave and current.. Firstly, a numerical ocean wave model is used to simulate nearshore ocean wave field, and the electromagnetic backscatter from sea surface under grazing incidence can be computed by using electromagnetic scattering theory, then the modulation mechanisms of X-band marine radar can be studied; by combining the measurements of an X-band coherent radar, the modulation transfer function that applicable to nearshore region can be established, and then the ocean wave spectrum and current of the whole observation area are obtained. Secondly, the non-Gaussian stochastic ocean wave theory is utilized to derive an anisotropy shadowing function, and then establish an algorithm to retrieve the significant wave height from X-band marine radar without external calibration, by combining with geometrical optics theory and digital image processing technique. Thirdly, study the impacts of rain on the imaging of X-band marine radar by analyzing experimental data, and propose a method to remove its influence. Based on this program, it is hoped that the imaging mechanisms of X-band marine radar can be clearly illustrated, and it is also helpful for the application of X-band marine radar in the monitoring of nearshore environments.

英文关键词： X-band marine radar;nearshore;ocean wave;ocean current;retrieval algorithm