High order nonlinearities in HF radar backscatter from the ocean surface
High order nonlinearities in HF radar backscatter from the ocean surface
复制标题
海面高频雷达反向散射的高阶非线性
DOI：
10.1049/ip-rsn:19952324
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
L. Wyatt
中科院分区：
文献类型：
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作者：
L. Wyatt
海浪的高频雷达测量利用产生接收信号的流体动力学和电磁过程的二阶理论。作者提供的证据表明二阶理论不足以解释所有情况下接收信号的功率谱。这并不是一个新结果；英国和美国都开发了雷达，可以降低在高海况下运行的无线电频率。然而，本文中的数据是在 HF 频段下半部分的频率下获得的，并且仍然显示出明显偏离二阶的证据。对海浪测量的影响似乎很小。结果揭示了这种效应的方向依赖性，这可以补偿双雷达频谱反演中的高阶非线性。建议使用二阶理论的偏离来提供粗略的有效波高估计。
HF radar measurements of ocean waves make use of a second-order theory for the hydrodynamic and electromagnetic processes that generate the received signal. The author presents evidence that the second order theory is not sufficient to explain the power spectrum of the received signal in all cases. This is not a new result; radars have been developed in both Britain and the USA that allow a reduction in radio frequency for operation in high sea-states. However, the data in the present paper were obtained at frequencies in the lower half of the HF band, and still show evidence of a significant departure from second order. The effect on ocean wave measurement appears to be small. The results reveal a directional dependence of this effect which may be compensating for the higher-order nonlinearities in the inversion of dual radar spectra. The use of the departure from second order theory to provide a crude significant waveheight estimate is suggested.