Basic research on ocean waves and currents using high-frequency ocean radar

高频海洋雷达观测海浪比海流观测困难得多。发展高频海洋雷达估计海浪是必要的。由于高频雷达对海洋的观测需要双雷达系统，天线的部署位置很难确定。通过将能量平衡方程引入到海面的无线电波散射分析中，我发展了一种从单个雷达阵列估计海浪的方法。根据能量平衡方程和多普勒谱与波谱之间的关系，由多普勒谱估计海浪谱。通过仿真研究发现，即使在非均匀波场的情况下，也可以估计出波浪谱。将该方法应用于观测数据，并将雷达估算的波高与现场观测结果进行了比较。我们发现这份协议很好。此外，还发展了海流的亥姆霍兹分解方法。最后，将雷达估计的波向分布与模型预测的波向分布进行了比较，两者吻合较好。

It is more difficult to observe ocean waves by HF ocean radar than ocean currents. The development to estimate ocean waves by HF ocean radar is necessary. Because dual radar systems are required for ocean observation by HF radar, it is difficult to find the place of the antenna deployment. I have developed the method to estimate waves from a single radar array by incorporating the energy balance equation into the analysis of radio wave scattering from the sea surface. Wave spectra are estimated from Doppler spectra on the basis of the energy balance equation and the relationship between the Doppler spectrum and the wave spectrum. It is found that wave spectrum can be estimated even in non-homogeneous wave field case from the simulation study. This method is applied to observed data, and radar-estimated wave heights are compared with in-situ observations. We found that the agreement was good. In addition, the method of the Helmholtz decomposion of ocean currents is developed. Finally, radar-estimated wave directional distributions are compared with those predicted by the model.The agreement of the wave directional distributions is good.