Questions tagged [unmanned-aerial-vehicle]

An Unmanned Aerial Vehicle (UAV) or Drone is an aircraft without a human pilot aboard.

34 questions with no upvoted or accepted answers
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Processing drone Images of body of water?

I took some pictures of a body of a body of water using a multi-spectral sensor attached to drone. When trying to process the image using Pix4D, more than 50% of pictures were unable to calibrated. ...
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82 views

GRASS GIS Segmentation issue on UAV image

I tried i.segment to perform segmentation on a part of UAV orthophoto image, but this always results in stripe-like rectangle segments which I do not expect. Could anyone figure out what happens? ...
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19 views

Calculating the coordinates of the selected pixel point from an image with known corner coordinates

How can I calculate the coordinates of the point(P) we want from an image with known corner coordinates? I want to find out respective coordinates from the selected the pixel of the image obtained ...
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0answers
24 views

Filter pictures in directory

I have a drone project with 50,000 pictures in 50 layers. Each layer has 2 to 5 zones. When I put them all together, we have a lot of overlap and in some places, we have up to 4 pictures of the same ...
2
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0answers
56 views

Radiometrically correct one UAV image

Does anyone out there know how to perform radiometric corrections on a single image taken with a multispectral sensor? I know there is proprietary software (such as PiX4D) that can do this; however, ...
2
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0answers
1k views

Changing the spatial resolution - stacked raster in R

Want to change higher spatial resolution UAV dataset stacked in R. Used raster package to stack the individual band. Want to change the spatial resolution to 1 m. stacked_UAV <- stack(stack_list)...
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221 views

DroneDeploy generated Ortho shows skewed in QGIS (projections OK?)

I've recently bought a drone and have been having a lot of fun enhancing maps with very detailed orthomosaics. The images place correctly once loaded in QGis, absolute positioning is good enough for ...
1
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1answer
64 views

R - Calculated shapes should be perfectly symmetrical but are not - why?

I'm trying to generate shapes to describe the no-fly-zone around airports. What I'm getting is shapes that are not symmetrical around the line of reflection, so this is either my lack of understanding ...
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190 views

Building zig-zag lines (Drone flight path)

I need to create a line path like the one below. I have to create a flight plan for an inspection with drone of a solar plant and I know the length of every single row and the distance between row, so ...
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80 views

Implementing BRDF in R

I use UAS to survey vegetation at subcentimeter resolution for my research and have found that bidirectional reflectance (BR) is a huge issue that impacts the reliability of estimates across ...
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0answers
66 views

Getting Geometry error: One or more input features have invalid geometry from QGIS

I am trying to use the "Split With Lines" tool to split a polygon layer that consists 1000+ separate objects. Geometry error: One or more input features have invalid geometry. The tool keeps ...
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0answers
42 views

Co-registering multiple temporal orthomosaics?

I have multiple (19) orthomosaics of the same approximate region taken regularly over the course of a couple months with a UAV. Some, but not all, include ground control points we placed in the scene....
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39 views

Adding tiled map to QGIS and exporting as web map

I have a set of drone imagery that was processed using Agisoft PhotoScan and converted to Map tiles. I am now looking on how can I add the map tiles in my QGIS for exporting as a web map? I have a ...
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30 views

Making Shapefile Hybrid Micro-Plot Boundary?

We would like to analyze in the field of precision agriculture the performance of a lot of hybrids that are planted in lines with no border between them. For this we need to make boundary or a border ...
1
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0answers
96 views

Photogrammetric point cloud classification

My question is regarding the point cloud classification and editing work for a photogrammetric point cloud generated using drone based imagery. My objective is the generation of a digital elevation ...
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0answers
70 views

Deriving Topographic Information from Geotagged Photos?

I wish to extract elevation data from geotagged photos? I have worked with DEM's and the open source CLI program: GMT for my graduate studies. I own a DJI Phantom 3 and used the trial version of ...
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0answers
79 views

Increasing performance without losing resolution when handling raster file in QGIS?

Orthomosaics generated by the processing of images obtained by UAV flights may often result in very heavy files that can take a long time to do simple tasks, just like to zoom on a specific region of ...
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0answers
83 views

Stacking/Aligning High-Res UAV Mosaics from Different Dates in QGIS?

I have two mosaics taken in different band sets respectively, on two different flights- of a crop field. The flights were taken a day apart, so the vegetation cover has not changed. The only issue is ...
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30 views

Problems with tree height in CHM

I did a drone flight over a forest plantation and got the DSM and DTM. Later, I was interested in calculating the height of the trees within a plot. For this, I did a subtraction between the DSM and ...
0
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1answer
16 views

Conversion of UAV DN values to reflectance

My aim is to carry out fusion between Sentinel 2 and UAV images. Sentinel images are already converted to reflectance values but UAV images are in DN number format. How can I convert UAV DN values to ...
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26 views

Understanding difference between Flight Angles (FlightYaw/FlightPitch/FlightRoll) and GimbalYaw/GimbalPitch/GimbalRoll

I am working on a project that requires me to extract/compute the orientation of the CAMERA in the world coordinate system. I have gone through the documentation (Flight Control, etc) but I am unable ...
0
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1answer
46 views

How to improve the horizontal and absolute accuracy of UAV layer

I am working with two digital elevation model data sets: LiDar and UAV DEMs. Both flights were conducted in the same location along a coastal shoreline showing the intertidal area with lots of bare ...
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27 views

Georeferencing Tool in QGIS 3.1: Getting NULL Z-Value with DSM layer when 'rubber sheeting'

I am using the Georeferencing tool/plugin in QGIS 3.1 to try and 'rubber sheet' two layers together. My reference sheet is a LiDar data set (ESPG 2961- NAD 83), pixel size 0.0709, -0.0709. The sheet I ...
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49 views

How to implement multilevel classification in eCognition (segmenting imagery at different scales)

I am trying to perform a ground cover classification in eCognition using UAV RGB imagery of a forest ecosystem, with multiresolution segmentation algorithm and NN classification. Since there are ...
0
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1answer
96 views

Georeferencing multiple “slightly” overlapping drone orthomosaics

Situation: I collected around 2000 drone images over 200 ha. My computer does not have the resources to render one large orthomosaic at once, so I decided to split my dataset into 8 and produce 8 ...
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28 views

Setting LAS Class Codes in ArcGIS Pro too slow

I have seen similar questions, but they don't quite relate to my particular issue. I classified habitat in a high-resolution drone orthomosaic image of a 300-m long stretch of beach, then used Raster ...
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45 views

Difference between GIS mapping and Photogrammetric mapping

I can't seem to understand both type of mapping. I am planning to make a drone for mapping and I am confused about picking one. My purpose is to take photos of specific area and do 3D modeling of that ...
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105 views

Automatically georeference non-intersecting UAS photos based on contained EXIF metadata

I need to know how to automatically create georeferenced rasters from multiple non-intersecting photos taken by UAS DJI Phantom 4 Pro. All EXIF metadata is present in every photo - coordinates, ...
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53 views

Best way to correct UAS imagery sun glint over a water surface

I have a challenge of where there is a sun glint which includes both specular and non-specular brightening of a water surface on Unmanned Aerial Vehicle (UAS) imagery. Please see the raw image below ...
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29 views

Calculating the error in a cut and fill between two surface models

I have a LiDAR suface model from 2006 and a LiDAR surface model from 2013. These two surfaces have about a 0.4 foot (0.12m) difference between the Z values on an adjacent road (2013 is 0.4 feet ...
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122 views

Creating 3D Local Scene using pointcloud, DSM, and orthomosaic from Drone in ArcGIS Pro?

I am trying to create a local 3D scene in ArcGIS Pro and display data fro drone flights. I have the orthomosaic from the flight as a .tif, the Digital Surface Model as a .tif, and my pointcloud from ...
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75 views

Filtering trees with Mac

I own about 200 acres of forest with about 350' of elevation change. I have a DJI 4 Advanced and my goal is to produce elevation maps to plan the building of one or more ponds. I've tried and failed,...
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0answers
834 views

Calculate reflectance for UAV images

I have high resolution images captured by a drone using a , they are RBG and NIR images. My question is how can I calculate the reflectance for the images, the values are currently in digital numbers (...
0
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1answer
127 views

Join GPS data and video from UAV to get frames from specific locations

Is there any piece of software capable to present gps track simultaneously with video ie. google maps data and allowing to clip a frame on selected locations on track? Both data and video are from ...