基于X波段雷达图像序列反演海洋表面流的算法研究

Research on Algorithm of Inversing Ocean Surface Current with a Sequence of X-Band Radar Images

海表面流是影响基于X波段雷达回波图像反演海浪参数精度的关键因素之一,针对海表面流不能由测量仪器直接测量的现状,本文对海表面流的反演算法进行了研究。在海表面流的反演过程中,提出建立带有约束项的能量价值函数,运用加权最小二乘法进行求解,得到海表面流反演公式,并提出考虑高阶色散关系可以提高表面流的反演精度。为了验证反演算法,采用X波段雷达现场遥测海浪获取海浪回波图像序列,对海浪回波图像存在的杂波问题,采用移动平均法及色散关系进行滤除,最后将算法运用到实际遥测的海浪回波图像中提取表面流,初步得到可行的结果。

The ocean surface current（OSC）is one of the key factors which affect accuracy in OSC parameters inversed with a sequence of X-band radar images.Although OSC cannot be directly measured by instruments,this paper investigates the OSC inversion algorithm.In the process of OSC inversion,the energy cost function with constraint terms is established,thus resulting in OSC inversion formulae.The optimum solution can be derived by weighted least squares method.The inversion accuracy can be improved by taking into account the high-order dispersion relationship. In order to test the inversion algorithm, a sequence of radar images are acquired by X-band radar, both moving average and dispersion relationship are used to filter noises in the images. The algorithm is finally validated with the reel X-band radar images, end the preliminary testing results show that the inversion approach is feasible.