16
votes
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Drone aerial imagery to QGIS
Yes you need to Georeference the images. The Exif data explains where the photo was taken, so it describes where your drone/camera was at that time and often many other values (heigth, bearing etc). ...
- 1,566
11
votes
Accepted
Merging drone/photogrammetry-derived DEM and satellite-derived DEM using ArcGIS Pro
Assuming:
both are in the same projection / coordinate reference system,
you have a Image/Spatial Analyst license, and
NoData has been set correctly on the High res DEM.
You could use a Raster ...
- 67.9k
7
votes
Drone aerial imagery to QGIS
Give RAPID for DJI a try. It will geo-reference and process up to 100 images from any DJI sensor or drone for free. The results are WGS84 Lat/Lon GeoTIFF format digital elevation models, point clouds ...
- 139
7
votes
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Georeference single drone image from EXIF data
As requested, posting my own (partial) answer. The actual math is not too bad, but there are surrounding issues making application difficult:
UAV camera focal length specs seem to be before sensor ...
- 8,316
6
votes
Determining bare earth DEM from unclassified LAS file?
This can be done with a pdal filter using either Simple Morphological Filter (SMRF) or Progressive Morphological Filter (PMF) algorithms.
Quick
pdal ground --cell_size=5 --extract input.laz out-...
- 28.2k
6
votes
Accepted
Obtaining the average red, green, blue values within grid cells in QGIS?
You can use Zonal Statistics tool.
- 77.8k
5
votes
Accepted
Postprocessing with NMEA-data if no rinex-data is available
It is not possible to do post-processing using NMEA output only, because it only contain final computed positions. And to do post-processing you need the pseudaranges, phases, etc. for each satellite ...
- 1,219
4
votes
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Drone that generates a point cloud from photography
Probably they have made a structure from motion function. With the mosaic of several pictures around an object you can create its 3d model and get also the point cloud. Thats nothing too spectacular. ...
- 6,265
4
votes
EVI calculation from UAV multispectral survey
The common definitions for these coefficients when using MODIS are: L=1, C1 = 6, C2 = 7.5. The C1 and C2 coefficients are aerosol resistance terms that rely on the blue band to partial out atmospheric ...
- 32k
4
votes
Accepted
Finding long, lat coordinates of points on building pictured by drone
You can't unless you know the distance from the ground, and the pitch, roll, and yawl of the camera (in addition to the CCD size and camera lens info you have). Plus, the onboard drone GNSS may not ...
- 10.2k
4
votes
Accepted
Why do RGB values seem very high for my multispectral orthomosaic imagery?
Your imagery is 16bit. 16bit data can contain a lot more information than 8bit. The signed range of integer values that can be stored in 16 bits is −32,768 to 32,767 and the unsigned range is 0 to ...
- 67.9k
4
votes
Accepted
Wrong parameters when georeferencing single drone images
My experience is with a Mavic Mini, which does not have published lens distortion specs and has only consumer-grade GPS, not RTK correction. With that caveat in mind, I've found you just need to ...
- 8,316
3
votes
Why is the altitude information of the geotag from a drone/uav/uas/rpas (Phantom 3) so innaccurate?
10-15 m is indeed the uncertainty that you get with a normal GPS in Z (it is roughly 3 times less accurate than XY). Furthermore, the XY errors are compensated by the large number of photograph on ...
- 49.8k
3
votes
Satellite signature of reindeer carcasses
I had a look at Sentinel imagery. The S2 images are too cloudy, as you can check here.
And with S1 there is an image on 27/8 (the day after the lightning) and another one with similar characteristics ...
3
votes
Seeking software for making digital elevation models from UAV aerial imagery
A high level method for creating Digital Elevation Models, Point Clouds and Orthomosaic maps using UAV aerial imagery and open source software (linux workflow).
Obtain a set of NADIR or NADIR + ...
- 139
3
votes
Seeking software for making digital elevation models from UAV aerial imagery
Delft University is doing a lot of research into CityGML, one of the upcoming standard formats for visualising 3D building information. They have a viewer and also this tool, to turn LIDAR info into ...
- 51
3
votes
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What is the difference between Key-Point, Tie-Point in Photogrammetry?
I found this page in the Pix4D documentation which states:
Keypoints are points of interest (high contrast, interesting texture)
on the images that can be easily recognized. The number of keypoints
...
- 21.9k
3
votes
Accepted
Smooth mosaicking of smaller orthomosaics to form a homogenous mosaic
That is noise / offset pixels or unexpected dark or light strips fringing an object.
Data from airborne multispectral or hyperspectral imaging scanners shows a pronounced striping pattern due to ...
- 1,701
3
votes
Seeking algorithms for DEM generation?
Based on this post How can i create a Digital Elevation Model from satellite Images?
If you have stereo pair of satellite images or overlapping aerial photographs or even UAV acquired imagery, you ...
- 12.1k
3
votes
Accepted
Software Recommendations: make a flyover video from GPX log?
I can't tell how that video was created, but you should be able to do something pretty similar with a combination of several techniques in Google Earth Pro. I'll list the general steps here, and you ...
- 2,988
3
votes
Accepted
Getting coordinates of pixel from georeferenced drone photo?
The approach you're looking for is called monoplotting in photogrammetry.
If given your assumptions on camera orientation, you will need a digital elevation model (unless you also assume the ground is ...
- 121
3
votes
Accepted
Abnormal Output of OpenDroneMap with GCP file
The problem in its processing is that it is georeferencing all ground control points with the same elevation, when they clearly do not have the same elevation.
The georeferencing process is not ...
- 14.6k
3
votes
Accepted
Higher spectral and spatial detail for high-resolution images using ArcGIS Pro Image Segmentation
The spectral and spatial detail values range from 0 to 20. Since they are using the default values of 15, you wouldn't be able to increase your spatial and spectral detail by much more. However, the ...
3
votes
Selecting grid cells by color of image
To solve your problem, you can use an expression to create a new field in the grid layer and then select them for a range of colour. Open the Field Calculator, select Create a new field (I suggest ...
- 3,898
3
votes
Accepted
Classification of drone imagery (RGB) with SCP
It is possible to split the orthophoto into 4 rasters with each a band and use them to create the ROI polygons.
Open SCP --> Click on 'Split Raster Bands' --> Select your orthophoto in Multiband ...
- 81
3
votes
Georeferencing single drone image from metadata (gimbal angles, flight angles)
An application like EXIFTool will allow you to see the pitch, roll, and yawl for both the camera and the aircraft. There are also Python solutions for reading the EXIF data from the aircraft camera ...
- 10.2k
3
votes
Mapping image from drone in QGIS
No, QGIS cannot exploit the image location, elevation,pitch, roll, and yaw to automatically georeference your images. You can manually georeference individual drone image yourself using QGIS. See ...
- 10.2k
3
votes
Can PPK (NOT RTK) be done with any mapping drone?
Post-processing depends on raw GNSS data being captured (pseudo-ranges for Code post-processing, Phase information for Carrier post-processing.) If the drone has only captured coordinates, you don't ...
- 754
3
votes
Merge multiple geo-referenced *,jpg files into a GeoTIFF in QGIS
No, this is not possible in QGIS. The georeferenced images will contain x, y, and z values embedded in the EXIF tags of the images. While there are several options for adding those images to QGIS ...
- 10.2k
3
votes
Problems importing DJI Phantom images into QGIS
"Coast of Africa" sounds like Null Island. This is very likely a CRS-Issue.
However, your point's are at the right location so probably it worked just right. And the import-photo tool ...
- 1,412
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