隨機媒質電磁散射研究.pdf

1、西南交通大學碩士學位論文隨機媒質電磁散射研究姓名：吳文濤申請學位級別：碩士專業(yè)：電磁場與微波技術指導教師：李敬19990301西南交通大學研究生學位論文第v頁AbstractElectromagneticcharacteristicinrandommediaiSaimport#mresearchfieldsinElectromagneticstodayIthasattractedincreasingattentionowingtoits

2、applicationinmicrowaveimaginggroundpenetratingradarandremotesensingetcnleelectromagneticscatteringindiscreterandommediaisthesubjectstudiedinthisdissertationthefollowingcontentsareinvolvedinpresentdissertationInthebeginni

3、ngpart，theresearchmethodforrandommediaissummarizedinchapterl，AnovelmethodforstudyingdiscreterandommediaispresentedbasedontheFDTDmethodandPMLabsorbinghounda／rconditionwhichhasbeendevelopedinrecentyearsInordertOmakeareason

4、ablediscreterandommediamodelAintroductionisnecessaryforFDTDmethodinChapter2ThenthePMLabSorbingboundaryconditionhasbeenmodifiedforUSedindensediscreterandommediaanda2DmodelfordiscreterandommediuminTMmodeiSmadeuDThetransien

5、tscatteredfieldsofthemodelalecalculatedwediscoverthepeakvaluetheenerg)andthefractaldimensionsofthescatteredfieldhavesomerelationwiththemediadensitySoweofferedsomewayst0acquirethemediadensityformthescatteredfieldsTherailw

6、ayballastWasstudiedinchapter42Dand3Dmodelshavebeenmadeupforraih^7a、ballastbasedonthemodelfordensediscreterandommediainchapter3Theintensitiesofthetransientelectromagneticscatteredfieldsareanal)zedandtheporosityofrailwayba

7、llastisobtainedbystudyingtheintensitiesofthescatteredfields1nchapter5theexperimentiSemployedtodetecttheporosityofraihvayballastbyusingelectromagneticpulsesandsomeexperimentdataareacquiredThesedatashowsthatthetheorymodels