土壤水分快速測量方法及其應(yīng)用技術(shù)研究.pdf

1、中國農(nóng)業(yè)大學(xué)博士學(xué)位論文土壤水分快速測量方法及其應(yīng)用技術(shù)研究姓名：趙燕東申請學(xué)位級(jí)別：博士專業(yè)：農(nóng)業(yè)電氣化與自動(dòng)化指導(dǎo)教師：王一鳴2002.5.1AbstractAspartoftheNational‘‘95”keyproject(No：96A2302—010)oninstrumentationsupportedbymeMinistryofScience＆TechnologyMinistrythisstudytookthebehavio

2、rofsoilwatersystemdielectricsasakeypointforfurtherdevelopmentandevaluationofanewkindofStandingWaveRatio(SWR)soilmoisturemeasuringsystemAseriesofacademicanalysisandalotofexperimentresearchonSWRbasedsoiImoisturesensorwerec

3、arriedoutandpresentedinthispaperOnthebasisoftheresearch，anewsoilmoisturesensor，whichitisverysuitableforfielduse，wasdevelopedAttheSaluetimeanewsystemtomeasurethespatialdistributionsofsoilmoisture，whichcanbeusedcombiningwi

4、thGlobalPositioningSystem(GPS)，wasdevelopedtooIngeneral，thestudyreportedin11isdissertationcanbebrieflysummarizedasfollows：1ThroBglltheoreticalanalysisonthebehaviorofsoil—watersystemdielectrics，itisproved山atthereafpartsof

5、thedielectricconstantun出rhj吐frequencyormicrowaveCallbeusedc0measuresoilwatercontentrapidlyThismethodcangetalotofmeasurementresultswithhighaccuracyandwideapplicabilityInaddition，theresultsareseldomaffectedbythespatialvari

6、ationofsoilpropertyAsafurtherapplicationoftheaboveresult，asoilmoisturesensorbasedonStandingWaveRatiowasdeveloped2InthisdissertationakeypointofthestudyistobuildupamathematicalmodelofthecharacterimpedancetheSWRsensoLThestr

7、uctureoffourequallengthprobescarlbeviewedasaspecialfonTlofcoaxialtransmissionlineCombiningthecharacterimpedanceofcoaxialandtheparalleltransmissionline，thecharacterimpedancemodelofprobewithequalinglengthwasbuiltupbyutiliz

8、ingmathematicaltheoryofapproachAndthen，thecharacterimpedancemodelofSWRprobewasbuiltupandvalidatedbyexperiments3ThespatialsensitivityofSWRsensorwasanotherkeypointinthisstudyByanalyzingelectrostaticdistributionaroundprobes

9、，itwasfoundthatthespatialsensitivityofSWRsensorisaconewhosecenteristhemiddleprobeandradiusissmallerthanthedistancebetweenmiddleprobeandaroundprobeThecorrectnessofthisconclusionhadbeenvalidatedbyexperimentstoo4Largeamount

10、soflabexperimentsshowedthattheconsistencyofSWRsensorisverygood，andtheSWRsensorhaveexcellentresultsineverykindsofsoiltexture，especiallyinloam，clayandacidloar／]TherewerenotbigvariationsamongtheirmeasurementresultsThecorrel

11、ativetoefficientoftlleirmeasureddataamvedat097UnderthesupportofFederalAgriculturalResearchCenter(FAL)ofGermanyaseriesofexperimentshadbeendonetocompareSWRsensorwithTDRsensormadebyGermanyandFDsensormadebyHollandTheresultss

12、howedthattheperformanceoftheSWRsensorisasgoodasothersensorsInaddition，theresultfurthershowedthatt11eSWRsensorhaveexcellentresultsIneverykindsofsoiltexture5Tomeettheneedsofsoilmoisturemonitoringandvariableirrigationameasu

13、rementsystemnamedModelTSCIVintelligentmonitorformeasuringthespatialdistributionsofsoilmoisturewasdevelopedSWRbasedsoilmoisturesensorwascombinedorconnectedwithA9132G10balPositioningSystem(GPS)inthesystemnecollectionandpro