drone imagery post-processing guide · this document is designed to serve as a beginners’...

DroneImageryPost-ProcessingGuide

CreatedbyMeganOssmann

attherequestofWorldWildlifeFund

Thisdocumentisdesignedtoserveasabeginners’guidelinetoprocessingrawimageryinDroneDeploy.Itcoversflightplanning,flightexecution,imageprocessing,imageexport,anduseinArcGIS.TheexampledatainthisguidecomesfromaflightthatwasconductedinJuly2018atNavarreBeach,FL.ClickthelinkbelowforalistofDJI-supporteddrones.https://support.dronedeploy.com/docs/supported-dronesForunsupporteddrones,flightplanningcannotbedonewithDroneDeploy.Post-processingofgeotaggedimagescanstillbecompletedwithDroneDeploy.1)FLIGHTPLANNINGFlightplanningiseasilydoneonacomputerorwiththeDroneDeployapp.OntheDashboardhomescreen,clickthe+signonthebottomandhit“planamapflight.”

Dragaboxovertheareayouwanttocover.Movethecornersoftheboxestomaketheareabiggerorsmaller.Onceyoucreatethisarea,theflightpathofthedronewillbeautomaticallycreated,withtheabilitytochangeitsdirectionunderadvancedsettings.Inthesidebar,thesettingscanbechangedtocreateyourflightplan.Theestimatedflighttime,areacovered,imagestaken,andbatteriesneededwillbeshown.Themaximumlegalflightaltitudeis400ft.Anidealaltitudewillbehighenoughtoclearthesurroundingobjects(trees,structures,etc.),butlowenoughtoprovideahigh-resolutionimage.Ifyourdroneiscapableofit,thenobstacleavoidanceshouldbeturnedon.

Expandthe“Advanced”settings.Here,youcanaltermoresettingsforyourflightplan,suchas:Sidelap:thepercentageofoverlapbetweeneachlegofflight.Increasingsidelapgenerallyincreasesyourchancesofagoodqualitymap.Therecommendedsettingsarebetween70and80%.Frontlap:thepercentageofoverlapbetweenoneimageandthenext.Increasingfrontlaphasminimaleffectonflightdurationandcanincreaseyourchanceofmakingasuccessfulmap.Therecommendedsettingsarebetween70and80%.FlightDirection:altersthepathwayofthedrone.FlightSpeed:recommendedflightspeedis15mphorless,toensurethathighqualityimagesaretaken.

StartingWaypoint:thefirstwaypointthatwillbeflownonyourmission.ManualCameraSettings:Unlessotherwisespecified,theautomaticsettingsfromDJIGOwillberetainedintheDroneDeployapp.Youcantoggleontheexposureand/orthefocussettingtoadjustthecamerasettingsinDJIGO.Here,youcanalsosetthefrequencyofphotostakenandadjustanyothercamerasettings.

Oncethisiscomplete,savetheflightplan.ThefilecanlaterbeopenedontheDroneDeployappandconnectedtoyourdrone.2)FLIGHTEXECUTIONOnceatthesite,poweronthedrone,acquiretheGPS,andcalibratethecompass.StartwiththeDJIapptoconfigureanycamerasettingsandverifythatthedronepassesthepre-flightchecklist.Openthemapwindowandverifythatthehomepositionistheactuallocationofthedrone.Ifitisoff,waitformoresatellitestoconnectandimprovethelocationaccuracyofthedrone.Oncethesestepsarecomplete,opentheDroneDeployapptoexecutetheflight.Here,youcanchoosethesavedflightplanorplananewmissiondirectlyontheapp.Thedroneshouldautomaticallyconnect.Hitthebuttononthebottom,andyouwillbetakentoanotherpre-flightchecklist.Oncethispassesyoucanhitthebuttononthebottomtostartyourflight.Notethatyoudonothavetobelocatedatthestartingwaypointtoconductyourmission.Thedronewilllaunchfromwhereveryouarelocated,automaticallyflytothestartingwaypoint,andthenbegincollectingimages.Oncethemissioniscomplete,itwillreturntotheoriginallaunchpoint.

Keepinmindthatyoudonotwanttobetoofarawayfromthestartingwaypoint,asitstilltakesbatteryforthedronetoflytothestartingpoint.3)IMAGEPROCESSINGUploadtheimagesfromtheSDcardtoyourcomputer.Forbestqualitymaps,manuallyreviewthephotosanddeleteanythatarenot“nadir”(lookingstraightdown),aswellasanythatareblurry,showpartofthehorizon,orhavelightingissues.GobacktoyourprojectonDroneDeployandselectthephotosthatyouwanttoupload.

Continueontoprocessing.Specifythemaptypeas“terrain”or‘structures”.Terrainisbestsuitedforlargetractsoflandsuchasagriculturalfieldsorforprocessingsitesurveyswithgroundcontrolpoints.Terraincanalsoproduce3Dmodels.Structuresareoptimizedforbuildings,statuesandotherverythree-dimensionalstructureswithoverhangs.

Whenyouareready,beginprocessing.Thiswilltakeseveralhours,dependingonthenumberofimagesandsettingsyouselected.4)EXPORTIMAGEOnceprocessingiscomplete,youwillseethefinal,stitchedimageofthearea.Thiscanbeviewedasa2Dmap(pictured),a3Dmodel,NDVIimageryasanindicatorofplanthealth,orelevationmodel.

Hitthe“Export”buttononthetopofsidebartoexporttheimage.Enteranemailaddresstobenotifiedwhentheexportiscomplete.Youcanchoosetoexporttheorthomosaic(pictured),NDVIimagery,elevation,or3Dmodel.YoualsohavethechoiceofexportingitasaGeoTIFF,JPG,orPDF,dependingonwhatyouneedasafinalproduct.Formapprojection,youhaveachoicebetweenWebMercator,WGS84oralocalcoordinatesystem.UseWSG84formostdesktopapplicationsandagriculturalsoftwaresuitesincludingArcGIS,QGIS,AutoCAD.UseWebMercatorforallweb-basedsoftwaresuites,includingGoogleEarth.Whenchoosingtheresolution,keepinmindthecapabilitiesofyourcomputerforrunningGISsoftware.

5)USEINARCGISOncetheimageisexported,youwillreceiveanemailwithalinktodownload.Oncedownloaded,unzipthefolderinyourdesiredlocation.CreateanewprojectinArcMaporArcProandaddtheimage.Therastershouldappearinthecorrectlocation,andcannowbeusedasabasemaporforanyothermappingpurposes.