基于正则化方法的高频地波雷达海浪方向谱反演

Regularization inversion method for extracting ocean wave spectra from HFSWR sea echo

提出了一种从高频地波雷达海面回波谱中提取海浪方向谱的新方法:基于高频电波海洋探测基本原理将线性化后的非线性积分方程离散为矩阵方程组,通过引入正则化数学模型将不适定方程转化为正规方程,然后采用奇异值分解法求解.对于正则化方法中正则化参数,采用L曲线法来确定.为了验证本文算法的有效性,分别在单部雷达和双部雷达探测下进行了不同噪声水平下的数值模拟,结果表明了该正则化反演方法的有效性.文中还给出了实测数据分析初步结果.该算法的工程性应用还需进一步研究.对于实际的地波雷达海浪反演具有良好的应用前景.

HFSWR （High Frequency Surface Wave Radar） is capable of all-weather remote sensing of large area ocean surface dynamics （currents, wind and wave） with relatively high precision. Its capability of currents detection has been considered satisfying the requirements for routine marine observations while its wind and wave outputs have not reached the matched status. The second-order Doppler spectra of the HFSWR sea echoes contain ocean wave spectra information. This paper proposes a new method for extracting ocean wave spectra from the Doppler spectra with HFSWR. The method is developed by introducing a regularization mathematics model to the discrete linearization of the integral equation based on the principle of HF radio wave ocean detecting. Solution of the discrete linearization of the integral equation is obtained by singular value decomposition （SVD） method, while the regularization parameter is determined by L-Curve. Validity and accuracy of the proposed method are demonstrated by numerical simulation with different noise levels both at single radar and two radars of the same coverage detecting which show good agreement： Non-directional spectra can be extracted from single radar and directional spectra can be obtained by two radars at the same coverage. Some preliminary results from measured data detected by HFSWR OSMAR071 located at Longhai of Fujian province are also introduced. Further study is needed for the practical use of this method. It is promising for HFSWR wave inversion in future applications.