简介：Thispaperanalyzesthepossibilitytodiscriminatebetweenconvectiveprecipitationandstratiformprecipitation.Thisstudyaimstoimprovethemeasurementofrainfallfromteledetectiondataobtainedbothonthegroundandinspace.Forthis,twoparameters,fractaldimensionandfractallacunarity,areconsidered.Tocalculatethefractaldimension,weusetheapproachofbox-countingandshowthatthefractaldimensiondiffersbetweenconvectivescellsandstratiformsones.Andthenthefractallacunarityparameteriscalculatedbyusingtheslidingboxesalgorithm.Thestudyforalltheregionsshowsthatprecipitationcellscanbedescribedbydifferentlacunaritieswhateverthescaleofanalysis.Wededucethatthetwoparameters,fractaldimensionandfractallacunarity,canbeusedtoclassifyprecipitationsinconvectiveregimeandstratiformregime.

简介：Afeature-constrainedstereomatchingalgorithmforlunarrovernavigationispresentedbasedontheanalysisofthestereovisionsystemandworkingenvironmentsoflunarrover.Infeature-matchingphase,edgepointsareextractedwithwavelettransformandareusedastheprimitivesformatching.Thenthreecriterionsareutilizedinturntoselectthecorrectmatchingpointswiththepyramidalsearchingstrategy.Asaresult,thealgorithmfindscorrespondingpointssuccessfullyforlargenumbersofedgepoints.Area-matchingisaccomplishedundertheconstraintofedge-matchingresults,andthecorrelationisselectedasthecriterion.Experimentalresultswithrealimagesofnaturalterrainindicatethatthealgorithmprovidesdensedisparitymapswithfairlyhighaccuracy.

简介：Bistaticforward-lookingsyntheticapertureradar(SAR)hasmanyadvantagesandapplicationsowingtoitstwodimensionalimagingcapability.Therecouldbevariousimagingconfigurationsbecauseofthegeometricflexibilityofbistaticplatforms,resultinginkindsofmodelsbuiltindependentlyamongwhichtherecouldbesomesimilareventhesamemotionfeatures.Comprehensiveresearchonsuchsystemsinamorecomprehensiveandgeneralpointofviewisrequiredtoaddresstheirdifferenceandconsistency.PropertyanalysisofbistaticforwardlookingSARwitharbitrarygeometryisachievedincludingstripmapandspotlightmodesonairborneplatform,missile-borneplatform,andhybridplatformofboth.Emphasisisplacedonazimuthspacevarianceofsomekeyparameterssignificantlyaffectingthesubsequentimagingprocessing,basedonwhichthefrequencyspectraarefurtherdescribedandcomparedconsideringrespectivefeaturesofdifferentplatformsforfrequencyimagingalgorithmdeveloping.Simulationresultsconfirmtheeffectivenessandcorrectnessofouranalysis.

简介：Inthisstudy,weextendourpreviousadaptivesteganographicalgorithmtosupportpointgeometry.Forthepurposeofthevertexdecimationprocesspresentedinthepreviouswork,theneighboringinformationbetweenpointsisnecessary.Therefore,anearestneighborssearchscheme,consideringthelocalcomplexityoftheprocessingpoint,isusedtodeterminatetheneighborsforeachpointinapointgeometry.Withtheconstructedvirtualconnectivity,thesecretmessagecanbeembeddedsuccessfullyafterthevertexdecimationanddataembeddingprocesses.Theexperimentalresultsshowthattheproposedalgorithmcanpreservetheadvantagesofpreviouswork,includinghigherestimationaccuracy,highembeddingcapacity,acceptablemodeldistortion,androbustnessagainstsimilaritytransformationattacks.Mostimportantly,thisworkisthefirst3Dsteganographicalgorithmforpointgeometrywithadaptation.

简介：Thecoherenceisameasurefortheaccuracyoftheinterferometricphase,andthesyntheticapertureradar(SAR)interferometriccoherenceisaffectedbyseveralsourcesofthedecorrelationnoise.ForthecircularSAR(CSAR)imaginggeometry,thesystemresponsefunctionisintheformoftheBesselfunctionwhichbringsahighsidelobe,andthehighsidelobeofCSARwillbeanimportantfactorinfluencingtheinterferometriccoherence.Theeffectofthehighsidelobeonthecoherenceisanalyzedanddeduced.BasedontheinterferometriccharacteristicsoftheslightdifferenceintheviewinganglesandthepotentialpixeloffsetintheinterferometricSAR(InSAR)images,arelationbetweentheradarimpulseresponseandthecoherencelossfunctionisderived.Fromtherelationalmodel,thecoherencelossfunctionduetothehighsidelobeofCSARisthendeduced,andcomparedwiththatoftheconventionalSAR.ItisshownthatthehighsidelobeofCSARfocusingsignalwillseverelyaffectthebaselinedecorrelationandcoregistrationdecorrelation.SimulationresultsconfirmthetheoreticalanalysisandquantitativelyshowthebaselineandcoregistrationdecorrelationdegradationduetothehighsidelobesofCSAR.

简介：Basedonthetheoryoffuzzylogic,themethodofobfuscatingcoefficientandreliabilitytofusetheinformationofhandgeometryandpalmprintsforidentitydiscriminationisproposed.Theexperimentprovesthatthemethodisusefulandeffective.Itsidentificationrateisupto90%,whichis20%-30%higherthanthatofusinghandgeometryorpalmprintssingly,thusitcanbewidelyusedinhighlydemandedsecurityfield,suchasfinance,entranceguard,etc.