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《基于星載sar數(shù)據(jù)和模式資料的海面風(fēng)場(chǎng)變分融合方法研究》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在應(yīng)用文檔-天天文庫(kù)。
1、基于星載SAR數(shù)據(jù)和模式資料的海面風(fēng)場(chǎng)變分融合方法研究4—.冠宇艾未華gi鑫戈書睿鎌蜂國(guó)防科技大學(xué)氣象海洋學(xué)院中國(guó)華明兵器試驗(yàn)中心海軍海洋水文氣象中心為實(shí)現(xiàn)合成孔徑雷達(dá)數(shù)據(jù)與數(shù)值預(yù)報(bào)模式資料融合,提高海面風(fēng)場(chǎng)精度和業(yè)務(wù)化運(yùn)用水平,提出了一種基于星載SAR數(shù)據(jù)與模式資料的變分融合方法。其研宄思路是采用二維連續(xù)小波變換提取SAR圖像中高精度風(fēng)條紋風(fēng)向,結(jié)合地球物理模型函數(shù)求解海面風(fēng)場(chǎng)的經(jīng)向分量和緯向分量,然后采用Kriging插值方法將數(shù)值預(yù)報(bào)模式風(fēng)速插值到SAR海而風(fēng)場(chǎng)覆蓋區(qū)域,得到SAR風(fēng)速觀測(cè)算子,由此構(gòu)建SAR風(fēng)場(chǎng)與模式風(fēng)場(chǎng)融合的代價(jià)函數(shù),并采用變分方法求解分析風(fēng)場(chǎng),最終得到融合后的海面風(fēng)
2、場(chǎng)結(jié)果。仿真分析結(jié)果表明,變分融合后的海面風(fēng)速和風(fēng)向結(jié)果更接近于理想值,尤其在SAR海面風(fēng)場(chǎng)覆蓋區(qū)域更為明顯。選取ENVISAT/ASAR資料和與其時(shí)空匹配的歐洲屮期天氣預(yù)報(bào)屮心模式風(fēng)場(chǎng)資料開(kāi)展實(shí)例驗(yàn)證,結(jié)果表明融合后的海而風(fēng)場(chǎng)結(jié)果比模式風(fēng)場(chǎng)更加接近于浮標(biāo)觀測(cè)結(jié)果。關(guān)鍵詞:合成孔徑雷達(dá);小波變換;變分融合方法;海面風(fēng)場(chǎng);基金:國(guó)家自然科學(xué)基金項(xiàng)FI(41475019,41375029)Researchonoceanwindvariationalfusionmethodbasedonspace-borneSARandmodeldataCHENGuanyuAIWeihuaCHENGYuxinGES
3、huruiYUANLingfengCollegeofMeteorologyandOceanography,NationalUniversityofDefenseTechnology;HuayinWeaponTestCenterofChina;NavyHydrometeorologicalCenter;Abstract:Basedonthespace-borneSAR(syntheticapertureradar)dataandmodeldata,avariationalfusionmethodispresentedtoimplementthefusionofSARdataandnumerica
4、lweatherpredictionmodeldata,andtoimprovetheaccuracyofseasurfacewindfieldandoperationallevel.First,two-dimensionalcontinuouswavelettransformisappliedtoextractwinddirectionofhighprecisionwindstripeinSARimage,andgeophysicalmodelfunctionisusedtocalculatemeridionalandzonalcomponentsofseasurfacewindfield.
5、ThentheKriginginterpolationmethodisusedtointerpolatethewindspeedofnumericalweatherpredictionmodeltothecoverageareaofSARseasurfacewindfield,resultinginthattheSARwindspeedobservationoperatorisobtainedandthecostfunctionofSARwindfieldcombinedwithmodelwindfieldisestablished.Thevariationalmethodisadoptedt
6、osolvetheanalysiswindfield.Finally,theseasurfacewindfieldresultsafterfusionareobtained.Simulationresultsshowthatthroughthevariationalfusion,theseasurfacewindspeedandwinddirectionresultsareclosertotheidealvalues,especiallyinthecoverageareaofSARwindfield.TheENVISAT/ASARsoundingdataandthespatialtempora
7、llymatchedmodelwinddataofECMWE(EuropeanCenterforMediumrangeWeatherForecasts)areselectedtocarryoutthecaseverification,andtheresultsshowthattheseasurfacewindfieldafterfusionisclosertothebuoyobservedresu