摘要
海面电磁回波频谱宽度与海浪波高密切相关,可应用频谱宽度进行海浪有效波高反演。本文应用线性滤波法仿真出了海表散射面元在雷达视向上的投影速度,建立了回波谱宽模型,分析了雷达空间分辨率、回波时间序列长度及海洋环境参数等因素对频谱宽度的影响,同时还针对如何在实际观测过程中选择回波时间序列长度、观测方位角等参数进行了讨论。最后还将理论结果与CSIR-X波段雷达实测数据谱宽估计结果进行了比较。结果表明,剔除雷达噪声以及频率泄露的影响后,基于高斯分布标准偏差的谱宽估计方法所得结果与理论结果吻合很好,这从而证明了理论结果的可靠性。本文所得结果对海浪有效波高反演具有一定参考价值。
The spectral width of the electromagnetic scattering from sea surface is closely related to the SWH(significant wave height),and thus the spectral width can be used to retrieve the SWH.In this paper,the linear filtering method is employed to simulate the radial velocity of the orbit velocity of the each scattering element on sea surface.Based on the radial velocity,we establish a spectral width model,and analyze the influences of spatial resolution,time sampling length and SWH on spectral width.At the same time,we also discuss how to select the parameters such as time sampling length and the azimuth angle during the actual observation.Here,the theoretical results are compared with the estimated results based on the measured data required by the CSIR-X band radar.The comparisons demonstrate that the spectral width obtained by the estimation method based on Gaussian distribution standard deviation agree well with the theoretical results after eliminating the effects of radar noise and frequency leakage,which proves the reliability of the theoretical results.The results obtained in this paper have certain reference value for the retrieval of the SWH.
引文
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