Questions tagged [ground-control]
distinctive points or markings (on the ground), whose positions (coordinates) are known and which are visible on photos or images -- used to help correctly position the photography or imagery for mapping or GIS
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How to transfer the GeoTIFF coordinates to pixel values
I have a function to convert the pixel values to the coordinates using the ground control points from the GeoTIFF file, which is given as below:
import rasterio.control
import rasterio.transform
def ...
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Georeferencing a historical map -
I am georeferencing a historical map and then trying to harmonise it with polygons from another file. I am trying to think about the best way to do this with respect to setting control points.
To give ...
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Adjust GeoTIFF in QGIS Georeferencer
I have 600 GeoTIFFs, old maps, that are roughly rectified by the map corners. I want to improve them with more GCPs so that the internal scale that differs a bit gets more correct.
Is there a way to ...
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How to adjust gdaltransform ground control point weighting control?
Let's take a 6 x 6 mile US PLSS township, and house numbers 800 to a mile. Using gdaltransform, given the coordinates of each section corner as our ground control points (-gcp 4800 4800 lon lat for ...
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How to align orthomosaics in QGIS?
I have processed about 8 orthomosaics from UAV data collection. They used RTK for georeferencing, but I guess it was not done properly. They did not use GCPs. Therefore, the orthomosaics do not align. ...
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QGIS3 georeferencing an unreferenced PNG and it isn't showing up on my base map
I'm using QGIS3 to try to georeference a screenshot of an old map of a state park (the PNG file) to a shapefile of the park's boundaries by matching points in the park's boundary. When I tell it to ...
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Using rasterio to rasterize vector data to a GCP referenced image
I am working with Sentinel-1 SAR images of a coastal area in ground range geometry (GRD product), which is defined by a geolocation grid of 10×21 ground control points. For further analysis, I need to ...
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Error when using CORS from TxDOT RTN to georeference DJI Phantom 4 RTK and Emlid Reach RS2
I use CORS from TxDOT RTN to georeference DJI Phantom 4 RTK and Emlid Reach RS2. I have been using it in Corpus Christi, TX with no issues. I do Structure from Motion (SfM) in Metashape, verify the ...
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How to give a coordinate to *.tif?
I have a *.tif, vintage aerial photo. Also, there is a metadata with coordinate information corresponding to the aerial photo. I would like to give that coordinate to the .tif.
First of all,
When I ...
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Georeferencing Polygon Features using ArcGIS Pro
I am using ArcGIS Pro to perform an image classification. To do this I need training data polygons derived from the image which is being classified. I created training data polygons outlining features ...
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Geo-reference vector data with GCP and target area
I have to geo-reference village maps(vector shapefiles) with the help of GCPs. In the transformation, the areas of the polygons need to match closely with their target values.
Is there a QGIS plugin ...
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GDAL GCP Transform - No GeoTransform() on GCP projected image?
I have a block of code that applies GCPs I have calculated to spatially project an image. Essentially, I am projecting the image by defining the corners as points 1,2,3,4.
# Set ground control points
...
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GeoReferencing Mars imageries
I am trying to make a 2D planer map of Mars, I have multiple non_georef images along with their geocentric lat and long. I am using gdal.GCP to georef these images; its working but something seems off ...
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Problem with wrong DEM output after georeferencing
My goal is to georeference a DEM tiff file that I have with a reference orthophoto.
Steps to reproduce
Open orthophoto (EPSG2056) in QGIS
Open the DEM (EPSG2056) in the Georeferencer
Add GCP (I am ...
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Batch Georeference with GCPs in QGIS OR merge GCPs
Problem:
I have ~100 black PNG tiles that show nothing but prairie creeks (black-creeks tiles)
I have ~100 map PNG tiles with creeks and background map (map-creeks tiles) that I can use to ...
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Duplicating Agisoft Metashape Projects
I am currently processing data for my Master's thesis and I need to process the same datasets many times with small changes each time. For example:
Not using GCPs
Using 9 GCPs
Using 1 GCP
Using RTK
...
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Does the QGIS Georeferencer have a point prediction function?
When taking GCP using Georeferencing in QGIS,
Is there a point prediction function?
For example, when working on GCP in an ERDAS program, put reference coordinates (ex: 10 coordinates)
After taking ...
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337
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How to georeference image with GCP in aux.xml using Affine transformation
I'm trying to automate georeference of big amount of non/georeferenced image file stored in TIF format to work with them in QGIS 3.16.4-Hannover.
These TIF files are 8 bits (B/N) and I only have aux....
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Difference between control point, reference point, and tie point
I georeferenced a map using grid coordinate and road network shapefile (e.g. intersection vertex) as a control point. I didn't acquire a control point through the survey.
I use "control point (...
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QGIS Georeferencer: How to deal with .points file using different CRSs?
I have some scanned maps as tifs and their corresponding .points files. The GCPs were set by different users erroneously using different CRSs. E.g. Of 340 points 180 were set using EPSG:23700, 160 ...
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Re-georeference an image that already has a spatial information
I have an aerial image that already has geo-spatial information (already georeferenced), but the original georeferenced location is very rough (not accurate). I wanted to create ground control points ...
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The transformation is already "north up" or a transformation between pixel/line and georeferenced coordinates cannot be computed
I tried to warp a raster image, a old airplane image, for projection by using gdalwarp.
My code:
gdalwarp -t_srs '+proj=utm +zone=52 +datum=WGS84' 1954_airplane_photo.tif air_warp.tif
But, I had this ...
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Georeferencing a historic map to a local custom coordinate system
I want to georeference a map (TIFF) from 1965 using the grid crosses as ground control points. The map is in the local coordinate system which I calculated and wrote a custom coordinate system for.
...
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QGIS custom coordinate reference system of a local site
I am creating a geo database for an archaeological excavation. We want to put data from a local system and from UTM35 in the same QGIS-project. I have Ground Control Points in both systems.
I setted ...
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Georeferencing historic airphotos along constantly-moving section of San Andreas fault?
I'm a geology graduate student working on a master's thesis project in which I'm measuring creep (movement) over time along a section of the San Andreas fault (in California, USA) using SfM derived ...
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Cannot georeference an image using a custom projection in QGIS
I am trying to georeference a map using a custom projection I created in QGIS. I get the error Transform failed: "Failed to compute GCP transform: Transform is not solvable" Does anyone have ...
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Georeferencing a GeoTIFF using with RasterIO
I am trying to Co-register a raster using Ground Control Points w.r.t. another raster using RasterIO. I have written a PoC, but having a bit of difficulty in measuring the quality of the final ...
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Convert XYZ coordinates from EPSG:2231 to EPSG:3857 (WGS 84 Pseudo Mercator)
I have some ground control points (GCPs) collected using coordinate system EPSG: 2231 (Colorado North USft). I have the data as a CSV. I want to convert the X,Y,and Z coordinates to WGS84 Psuedo ...
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How do we georeference a toposheet using GCS or PCS?
I am new to the GIS domain. I need to georeference a toposheet, Datum - WGS84, 1:50,000 scale map. I have done the georeferencing using WGS for GCP's and then projected to WGS_94_UTM Zone 43N, using ...
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What is the proper way to georeference an image based on GCP using GDAL tools
I am trying to do the Georeferencing using CLI provided by the GDAL as it is doing in the QGIS.
Tools useful are
gdal_traslate
gdalwrap
gdaltransform
I have a gcps as below:
-gcp 3.5665368079674 172....
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How to georeference images with GCP's in straight line?
I would like to use the Thin Plate Spline tranformation type in the QGIS georeferencer plugin. The image I'm trying to georeference is a sequence of aerial images which have been merged manually. I ...
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Point Residual in photogrammetry
I have been working on old aerial photos on Agisoft Metashape and there is a button that company added this called the "show" point residuals.
When you turn it on, it shows where the line shows.
I ...
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DSM results from WebODM are not correct [closed]
I am new to WebODM and I am trying to generate DSM and Orthomosaic images using default settings in WebODM.
The Orthomosaic image is correct by providing GCP but the DSM file is having inaccurate ...
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842
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Setting GCP in OpenDroneMap Project
I have run OpenDroneMap(ODM) on a bunch of drone images of a particular area. I have set the Ground Control Points(GCP) using Webodm gcp interface. Now, I have a gcp_list.txt file containing the ...
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Abnormal Output of OpenDroneMap with GCP file
I am using a gcp_list.txt file with the following text:
I am supposed to get a geo-referenced mesh object like this:
But, I am getting something like this:
I am running ODM locally in ubuntu 16 ...
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Is there a limit to the number of GCPs that can be used?
I am trying to georeference an image using many (>1,000,000) GCPs (derived by matching two images using triangulation). However, after many attempts doing this in different ways I think I found that ...
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Saving osgeo.gdal.Dataset as GeoTIFF or JPEG with world files using GDAL from Python?
I am trying to take a plain JPEG with no spatial references, apply ground control points (GCPs) to it, and output a georeferenced GeoTIFF or JPEG with world files.
I found some code that seemed like ...
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Using Ground Control Points in Agisoft Photoscan?
I'm fairly new to the Agisoft Photoscan program, but I am trying to build several models using aerial imagery and highly accurate GCPs, with coordinates collected in the field. I align my photos and ...
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Ground Control Point Experience
I have a number of aerial images that do not align with where my GPS says I am. For example, I am standing at the intersection of two roads with a Trimble R10 and a handheld IOS device with the ...
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Deleting GCP set in GEOTIFF?
How to delete GCP set in GEOTIFF?
I have some GEOTIFF files.
They have been set for GCP, but I made a mistake.
Therefore, I want to take the following procedure.
Delete the set GCP.
Grant new GCP.
...
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Using gdallocationinfo on a rotated SAR image to get pixel value at coordinates
Some information: I must not re-sample the image, the pixels are rotated, and the image opens in ArcMap just fine.
now, there are 15 GCPs on the raster (which make the pixels rotate)
Progress:
1.When ...
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ArcGIS 10.5 - Testing the accuracy of a satellite image's georeferencing using dGPS ground control points
I want to test the accuracy of the georeferencing of a satellite image by using a set of independent ground control points collected in the field via differential GPS.
Is there a tool/method/...
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Creating a GCP (*.points) file from a Shapefile (points layer)?
I have created a points layer which represent Ground Control Points (GCP) for georeferencing scanned topographic maps via 'Add Layer > Add Delimited Text Layer', where I saved coordinates in a .csv ...
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Georeferencing CAD drawing and setting ground control points in GRASS?
I'm fairly new to QGIS and Grass GIS, and learning the interface.
I have a CAD drawing that has no coordinate system assigned and needs to be georeferenced to NAD83 HARN Northern Colorado (feet).
I'...
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Error importing ground control points ArcGIS Pro
I am working on processing aerial images from an automated drone flight in ArcGIS Pro. The photos import into the Ortho Mapping workspace just fine, and the Quick Adjust alignment runs without ...
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What does control points look like in viewer ? How spread do they need to be ?
I have a question for you . As I am working on using ERDAS Autosync to orthorectify from an ungeoreferenced aerial photos to known reference image. I have a DEM that to go with it as well.
I ...
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Georeferencing X Y (AND Z) with GCPs in QGIS
I have GCPs recorded to centimeter precision in lat, long, and elevation.
I want to georeference my UAV-photogrammetry-generated GeoTIFF and DEM with these GCPs (since the GPS on my UAV is only ...
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Editing/adding GCPs using QGIS?
I have georeferenced some aerial images, loaded in QGIS and saved them (files .tiff, aux.xml and .points). These images overlap, however I found that some details in the borders did not match exactly ...
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How are ground control points collected that aren't in WGS84?
I understand that if you collect GCPs using an RTK GPS they are in WGS84 / EPSG:4326 - and you could then convert them to another EPSG. But I'm wondering how GCPs are collected in other coordinate ...
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Are all remote sensing landcover/use classifications without ground survey scientifically invalid? [closed]
It is on the need of accuracy assessment of classification product.
Land cover/use classification is a prominent analysis in remote sensing. Now the question is if I generate a landcover from LANDSAT,...
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