The goal of this work is to develop and evaluate techniques for the retrieval of wind and internal wave (IW) information from marine X-band radar data. Here, the focus lies on shipborne marine radar data. Such data present the challenge that the existing wind streak-based approach for retrieving wind directions cannot be directly applied.;Grazing incidence HH-polarized (horizontal transmit and receive) X-band radar data exhibit a single intensity peak in upwind direction. To retrieve the wind direction, this work proposes a least-squares fit technique that identifies the upwind peak in the range-averaged backscatter dependency on the antenna look direction. This technique requires no motion correction and is therefore well-suited for shipborne data. In addition, it functions well even if sections of the radar field of view are masked. An empirical model function is derived to retrieve the wind speed from the mean radar backscatter intensity. Data from the U.S. Office of Naval Research (ONR) Impact of Typhoons on the Ocean in the Pacific (ITOP) experiment are used for a comparison between radar-based wind estimates and anemometer measurements. The two data sets show good agreement.;In addition, this work proposes a technique that uses geolocated marine radar data to extract wind streak information through a localized Radon transform. To compare streak- and upwind peak-based wind direction retrieval techniques, fixed and moving platform marine radar data from the ONR-sponsored High Resolution Air-Sea Interaction (Hi-Res) experiment are used. Wind directions obtained using the upwind peak method show a better agreement with the reference data than those obtained from the wind streaks. The difference between fixed and moving platform for the wind streak approach indicates that the image geolocation affects the wind retrieval negatively. Standard deviations as low as 6.0° and 0.42 m/s for the comparison between radar-based and reference wind data show that marine radars can yield highly reliable wind estimates.;Regarding IWs, a new fully automated tool to retrieve IW signatures from marine radar image sequences is developed and applied to data collected during ONR's Non-Linear Internal Wave Initiative / Shallow Water '06 experiment (NLIWI/SW06). Marine radars have the advantage over satellite systems that their high temporal resolution enables the study of the IW evolution. The proposed technique employs our knowledge about the wind dependency of the radar backscatter to correct for the image ramp, i.e. the return signal's dependency on range and antenna look direction. The ramp-corrected radar images are then geolocated and averaged, which greatly enhances the IW signal. By determining the IW group velocity and correcting for it before the radar images are averaged, the IW signal is further enhanced. Such pre-processing enables a reliable retrieval of IW surface signatures by clustering local peaks and troughs, and tracking those clusters through time.;This work also includes a detailed analysis of data collected during the tracking of a particularly energetic IW. The radar-derived time series of IW speed, direction, and soliton maps yield unique information about the IW's spatio-temporal evolution, including evidence of wave-wave interactions. In addition, it is demonstrated that marine radar data can be used to retrieve information about the interior ocean dynamics associated with the IW. The IW-induced backscatter modulation is correlated with the measured surface current gradients and IW amplitudes. Alternatively, results are shown where IW amplitudes were derived from the distances between positive and negative radar backscatter peaks. This approach was first introduced by Xue et al. (2012) and is based on an extended Korteweg-de-Vries (eKdV) equation. This approach has the advantage that it is much less dependent on the prevailing wind conditions. (Abstract shortened by UMI.).
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机译：这项工作的目的是开发和评估从船用X波段雷达数据中检索风和内波（IW）信息的技术。在此，重点放在舰载海上雷达数据上。此类数据提出了挑战，即无法直接应用现有的基于风条纹的方法来检索风向。掠入射HH极化（水平发送和接收）X波段雷达数据在上风向显示出单个强度峰值。为了获取风向，这项工作提出了一种最小二乘拟合技术，该技术可确定范围平均背向散射对天线视线方向的逆风峰。该技术不需要运动校正，因此非常适合船载数据。此外，即使雷达视场的某些部分被遮挡，它也能很好地发挥作用。导出经验模型函数，以从平均雷达反向散射强度中检索风速。来自美国海军研究办公室（ONR）的台风对太平洋海洋的影响（ITOP）实验的数据用于基于雷达的风速估计和风速计测量之间的比较。这两个数据集显示出良好的一致性。此外，这项工作提出了一种技术，该技术使用地理定位的海洋雷达数据通过局部Radon变换提取风条纹信息。为了比较基于条纹和上风峰的风向检索技术，使用了来自ONR赞助的高分辨率空海相互作用（Hi-Res）实验的固定和移动平台海上雷达数据。与从风条纹获得的风向相比，使用逆风峰值方法获得的风向与参考数据显示出更好的一致性。风条纹方法的固定平台和移动平台之间的差异表明，图像的地理位置会对风的获取产生负面影响。用于比较基于雷达的风数据和参考风数据的标准偏差低至6.0°和0.42 m / s，表明船用雷达可以产生高度可靠的风估计值;关于IW，一种新的全自动工具可以从船用雷达中检索IW信号图像序列被开发出来并应用于在ONR的非线性内部波动倡议/浅水'06实验（NLIWI / SW06）期间收集的数据。相对于卫星系统，船用雷达的优势在于其高时间分辨率可以研究IW的演变。所提出的技术利用我们对雷达后向散射的风依赖性的知识来校正图像斜率，即返回信号对距离和天线视线方向的依赖性。然后对经过斜波校正的雷达图像进行地理定位和平均，这可以大大增强IW信号。通过确定IW组速度并在对雷达图像求平均之前对其进行校正，可以进一步增强IW信号。通过对局部峰和谷进行聚类并通过时间跟踪这些聚类，这样的预处理能够可靠地检索IW表面特征。这项工作还包括对在跟踪特别活跃的IW期间收集的数据的详细分析。雷达得出的IW速度，方向和孤子图的时间序列会产生有关IW时空演变的独特信息，包括波波相互作用的证据。此外，证明了海洋雷达数据可用于检索有关与IW相关的内部海洋动力学的信息。 IW引起的反向散射调制与测得的表面电流梯度和IW幅度相关。或者，显示的结果是IW振幅从正负雷达反向散射峰之间的距离得出。这种方法是由Xue等人首先引入的。 （2012）并基于扩展的Korteweg-de-Vries（eKdV）方程。这种方法的优势在于，它对当前风况的依赖性大大降低。 （摘要由UMI缩短。）。
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