Development of a 3D thermal imaging camera ... - FLIR

To create the system, the team selected four A65sc FLIR thermal imaging cameras as well as four compact RGB cameras from another manufacturer that produce ... Icon-ContactSalesShapeGridViewExportedfromStreamlineApp(https://app.streamlineicons.com)ModelSelectorModelSelector Obliqueaerialcamerasystems—whichrecordhigh-resolutionthree-dimensionalimages—areoftenusedtomapurbanareasandobtaingeographicdatafromtheair.Until2017,noneofthesesystemswereabletorecord3Dthermalimages.Inresponsetothisneed,ateamatAnhaltUniversityofAppliedSciencesinDessau,Germany,developedathermalimaging/RGBsystemthatproduces3DimagerybyoverlappingpicturesfromfourdigitalandfourFLIRA65sccameraswith25°fieldsofview. TheInstituteforGeoinformationandSurveying TheAnhaltUniversityofAppliedSciencesinDessauhasbeenprovidingcoursesinthefieldofsurveyingsince1992,andingeoinformaticssince2002.TheformersurveyingdepartmentwastransformedintotheInstituteforGeoinformationandSurveying.AsaninstitutewithintheFacultyofArchitecture,FacilityManagementandGeoinformation,itbundlestheacademicandresearchcompetenciesofthesurveyingandgeoinformaticsdisciplines.Inadditiontoteaching,theinstitutefocusesonappliedresearch. TheIdeaandItsAreasofApplication Oneoftheinstitute'sprojectsconsistedofdevelopinganewthermalimagingandRGBcamerasystem,whichproduces3Dimagesbyoverlappingthepicturestakenfromagyrocopterusingeightcameras.ProfessorLutzBannehr,whoheadstheInstitute'sdepartmentsofGeodataAcquisitionandSensorTechnology,cameupwiththeideainApril2016.While3Dcamerasystems(so-calledRGBobliquecamerasystems)withveryhighresolutionswereavailable,noneofthesesystemscouldprovidethebenefitsofthermaldata.ProfessorBannehrhadexperiencewiththermalimaging,havingpurchasedaFLIRSC3000cooledinfraredcamerain2001andparticipatedinthermographytraining.Hewascertainthatasolutionusinguncooledthermalcameraswouldbefeasible.Therecouldbemanypotentialuses,including:collectinginventorydata,surveillance,volumemonitoringinopencastminingoperations,forestfiremonitoring,insulationanalysis,yieldestimatesforphoto-voltaicandsolarheatingsystems,environmentalmonitoring,geologicalandtopographicalimaging,andevenproducingdigitalcitymodels. TheProject ProfessorBannehrsubmittedtheresearchproposalandputtogetherasmalldevelopmentteamincludinghisPh.D.studentChristophUlrich,HermannKaubitzschfrombgkinfrarotserviceGmbH(Riesa)—aFLIRintegrationcompany—andHenrikPohlfromgyrocopterproducer,AirborneTechnicalSystems(Berlin).Evenwithoverlapsof85%inbothlengthandwidth,conventionalhigh-resolutioncamerascouldnotdepicteverydetailofthesidesofbuildings.Therefore,theteamdesignedasystemconsistingoffourRGBcamerasandfourthermalimagingcamerasarrangedsothattheirimageswouldoverlaptoproduce3Dthermalimagesand3Dgeodata.Thisdatacouldthenbeanalyzedandevaluatedusingstandardsoftware. TheCameras Tocreatethesystem,theteamselectedfourA65scFLIRthermalimagingcamerasaswellasfourcompactRGBcamerasfromanothermanufacturerthatproduceimageswithapproximately5megapixels.KaubitzschrecommendedtheteamusetheFLIRA65scthermalimagingcamera"duetoitsgoodthermalimageresolutionof640×512pixels,itsframerateof30Hz,itsEthernetportanditsextremelycompactdimensionsof106×40×43mm."HermannKaubitzschwasalsoresponsibleforsynchronizationandevaluationofthecameras,whichturnedouttobenosmalltask. TheAOS-Tx8includesahelicalarrangementoffourA65scFLIRthermalimagingcamerasandfourcompactRGBcameras,whichallproduceoverlappingimages. AOS-TX8ControlsandSpecifications Ateamofstudentsdevelopeda3Darrangementfortheeightcameras,whichhadtotakeupaslittlespaceaspossibleintheultralightaircraft.Anopencustom-madebaseplatewasevenmadetomountthesysteminthegyrocopter.Anameforthe"AerialObliqueSystem"wasalsoquicklyfound:AOS-Tx8.ThesystemiscontrolledviaEthernetandimagedataisdisplayedona10-inchscreen."Afewyearsago,weexperimentedwithadifferentthermalimagingcamera,butcontrollingitviaEthernetdidnotworkaspromised,"explainedProfessorBannehr."WiththeFLIRA65scmodels,however,thiswasnoproblem."TheentireAOS-Tx8systemonlyweighs11.6kgandmeasures330×400×320mm.Itprovidesforconnectionsformanualcameraoperationandtheflightmanagementsystemaswellasamouse,screen,keyboard(allviaUSB)andthepowersupply. Duringcalibration,theIRcamerasshowedadeviationofupto5°Ccomparedtoareferencespotlight.Camera1wasselectedasareferencecameraandtheothercameraswereadjustedtomatchitsreferencevalues. SynchronizationoftheThermalImagingCameras TheoverlapbetweentheFLIRcamerasis12%or3°.ThefourFLIRthermalimagingcamerashadtobesynchronizedtoobtainusefuldataandavoidtemperaturevariationsinthemeasuredvalueswheretheimagesoverlap.Duetotechnologicalreasons,uncooledthermalimagingcamerashaveavarianceofupto±5%intemperaturemeasurement.Atestofallfourcamerasusingareferencespotlightshowedthatthepredicteddeviationswerealsopresent,butthattheyweredistributedlinearlyacrossthespectrum.Itwasthereforepossibletouseoneofthecamerasasareference camera(ideallytheonewiththemeanvalue)andthenadjusttheothercamerastomatchthereferencecamera. MaidenFlight OnAugust15th,2017thetimehadcometotryitout.TheAOS-Tx8hadbeenmountedinthegyrocopterandwasreadytomakeitsinitialmeasurementsfromtheair.Thesequenceofeventshadalreadybeenclearlydefined.TheteamusedflightplanningprogramstoplotthemaidenvoyageandusedGoogleEarthforthemapdata.Theflightplanningdataincludingthepointswherepicturesaretobetakenarecopiedintotheflightmanagementsystem.  TheAOSTx8mountedinthegyrocopterbeforeitsmaidenflightinAugust2017. Duringflight,thisdatawasusedtotriggertheAOS-Tx8andothersensors.FollowingtestflightsovertheAnhaltUniversity'sStrenzfeldcampus,flightswerealsomadeinAugustoverMagdeburg.Imageswerenotonlytakenfromaverticalangle(so-calledIRorthographyimages),butalsousedtoproducelarge-scale3Dthermalimagesthatalsoshowedeffectivenessofinsulationonbuildings. ResultsAchievedbytheAerialObliquSystem(AOS-TX8) UsingtheAOS-Tx8,itispossibleforthefirsttimetoobtainadigitalsurfacemodelwithprecisedeterminationofbuildingheightsaswellasadigitalterrainmodelinRGBandinfrared.TheAOS-Tx8iseasytooperateandthedatacanbeevaluatedusingstandardsoftwareproductssuchasPhotoscanorPix4D. Outlook TheinstitutenowalsohasaFLIRA655scforaerialdatacollectionthatdoesnotrequire3Dimaging.WecanthereforelookforwardtothenextinfraredresearchprojectconductedbyProfessorBannehrandhisinnovativeteamattheInstituteforGeoinformationandSurveyingattheAnhaltUniversityofAppliedScienceinDessau. 3DAerialThermalImages 3DthermalimageofMagdeburg(center:Magdeburgcathedral). IRorthographicimageoftheAnhaltUniversityofAppliedScience'sStrenzfeldcampus. RelatedArticles Fundamentals WhatisHighSensitivityMode? Learnmore CaseStudy FLIRThermalImagingCamerasRevealtheSecretsofCoexistingInsects ReadtheStory TechNote FLIRT500-SeriesMacroMode:single-lenssolutionforimagingsmalltargets ReadtheStory × ConfirmLocation Singapore UnitedStates