本文為荷蘭代爾夫特理工大學（作者：J. Friedman）的碩士論文，共97頁。

一種被稱為“Sand Motor”的大型人工育灘工程已經在荷蘭沿海實施，以作為一種為未來20年設計的“自然環境”解決方案。鑒于該項目的長期性，目前正在使用現場測量和遙感技術相結合的方法。一部X波段雷達系統部署在Sand Motor，但需要進一步研究其在這樣一個動態沿海氣候中的適用性。利用三維快速傅立葉變換（FFT）可以將雷達數據處理成波浪、海流、水深等水動力參數。這項技術是非常理想的海岸工程應用，因為它提出了一個相對輕松的方法來捕獲高分辨率的時空水動力參數。

本研究的目的是研發一個Sand Motor X波段雷達的深度反演模型，以進一步研究遙感作為估計近岸水深和水動力學的精確工具。該模型應能從高時空分辨率的X波段雷達原始圖像中準確估計水動力參數。本文介紹了2013年10月Sand Motor X波段MATLABr擬合（XMFit）模型的建立、標定和驗證。XMFit是一種基于現場對比提取近岸水動力的有價值的遙感工具。Nortek B.V.開發的SeaDarQ軟件也被用作質量基準。Sand Motor結果表明，與目前可用的SeaDarQ軟件相比，XMFit更加健壯和準確。本文完成了靈敏性分析，以進一步分析與XMFit精度相關的時空模式。空間統計表明，雷達區域邊緣的誤差很大，通過實施2.5公里的空間截止，雷達覆蓋的范圍減少了。較小的區域使得散射小得多，近似恒定的線性偏差為2m。以下海洋氣象條件被發現與XMFit中的高精度周期測量相關：

?有效波高大于1 m

?風速應大于12 m/s

?風和波浪應在45°觀測范圍內。

海洋氣象條件有助于得出以下結論：XMFit需要在k-ω空間中傳播光譜，以幫助約束彌散面。這一發現與當地產生的風浪（通常稱為風海）直接相關。基于空間和時間限制的理想結果進一步將線性偏差降低到約1.6 m。理想條件表明，雷達反演和原位水深測量與流體力學之間有更好的一致性。漲潮期間XMFit的誤差與Sand Motor周圍復雜的近岸流體力學有關。注意，Sand Motor處的漲潮顯示出復雜的流動結構（即背風面上的分層和大規模渦流形成）。XMFit將這些在漲潮期間明顯的復雜三維水流結構平均成一個大的計算立方體，這大大簡化了流體力學的分析。最后，這項工作強調需要對XMFit進行更多的研究，因為XMFit被證明適用于荷蘭沿岸的Ameland海灣。瞬時結果增加了XMFit的可信度，因為它能夠提取復雜的落潮三角洲、洪道方向和相干波誘導流。

A large-scale nourishment known as the SandMotor has been implemented along the Dutch coast as a “Building with Nature”solution designed for the upcoming 20 years. Given the longterm period of theproject, a combination of in situ measurements and remote sensing techniquesare currently in use. An X-band radar system is deployed at the Sand Motor, butrequires further research into its applicability in such a dynamic coastalclimate. Radar data can be processed into hydrodynamic parameters such as waves,currents and bathymetry information through use of a 3D Fast Fourier Transform(FFT). This technology is highly desirable for coastal engineering applicationssince it presents a relatively effortless method to capture high resolutionspatial and temporal hydrodynamic parameters. The objective of this research isto develop an X-band radar depth inversion model at the Sand Motor for furtherinvestigation into remote sensing as an accurate tool for estimating nearshorebathymetry and hydrodynamics. The developed model should be able to accuratelyestimate hydrodynamic parameters from raw X-band radar images with hightemporal and spatial resolution. This thesis explains the development,calibration and validation of the X-band MATLABr Fitting (XMFit) model at theSand Motor for a single storm in October 2013. XMFit proved to be a valuableremote sensing tool for extracting nearshore hydrodynamics based on in situcomparisons. The SeaDarQ software developed by Nortek B.V. is also used as aquality benchmark. The storm results showed that XMFit is more robust andaccurate relative to the currently available SeaDarQ software. A sensitivityanalysis was completed to further analyze the spatial and temporal patternsassociated with XMFit accuracy. Spatial statistics indicated high error aroundthe edges of the radar domain, which led to a reduced radar footprint byimplementing a spatial cutoff of 2.5 km. The smaller domain results in muchless scatter with a near-constant linear bias of 2 m. The following metocean limitswere found to be associated with periods of high accuracy in XMFit.

? Significant wave height greater than 1 m? Wind speed should be greater than 12 m/s ? Wind and waves should align within45? The metocean limits help conclude that XMFit requires spectra spreading ink ? ω space to help constrain the dispersion shell. This finding directly linkswith locally generated wind waves, more commonly referred to as wind sea. Idealresults based on the spatial and temporal limits further reduced the linear biasto approximately 1.6 m. The ideal conditions show a much better agreementbetween radar-derived and in situ bathymetry and hydrodynamics. A relationshipbetween the inaccuracy of XMFit during flood tide was linked to complexnearshore hydrodynamics around the Sand Motor. Note that the flood tide at theSand Motor exhibits complex flow structures (i.e. stratification and largescale eddy formation on the lee side). XMFit averages these complex 3D flowstructures evident during flood tide into a single large computational cube,which drastically simplifies the hydrodynamics. Lastly, this work concludes byemphasizing the need for additional research into XMFit since it provedapplicable at the Ameland inlet along the Dutch coast. Instantaneous results increaseconfidence in XMFit given its ability to extract the complex ebb-tidal delta,the orientation of the flood channel and coherent wave-induced currents.

引言

文獻回顧

研究目標

數據庫

XMFit的研發

理論驗證

結果

討論

結論

研究建議
附錄A XMFit空間校正
附錄B 非線性波理論測試
附錄C 單時間步進比較

更多精彩文章請關注公眾號：

總結

以上是生活随笔為你收集整理的【雷达与对抗】【2014.06】荷兰人工育滩工程Sand Motor的X波段雷达深度反演模型研制的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。