How to create a GCP

General Help
#1

Hello I am novice if you could explain to me how to create a GCP file to make an orthophoto. Thanks in advance.

Original Text

Bonjour je suis novice si vous pouviez m expliquer comment créer un fichier GCP pour réaliser une orthophoto . Merci d avance .

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#2

Welcome!

We have some documentation here:
https://docs.opendronemap.org/gcp/

Translated Text

Bienvenue!

Nous avons de la documentation ici:
Ground Control Points — OpenDroneMap 3.0.5 documentation

[Traduit automatiquement]

#3

Just wanted to make a suggestion, since I had some trouble figuring this out too (specifially with non-UTM data). We collect our GCPs using the app SW Maps, which outputs information in lat/long rather than UTM, and we have been able to use that data with the GCP editor in webodm by formatting our field data like this and uploading it to the GCP Interface:

EPSG:4326
-84.91569096 39.81686827 255.031 0 0 gcp1
-84.91559972 39.81666929 255.216 0 0 gcp2
-84.91511656 39.81690010 256.064 0 0 gcp3
-84.91484749 39.81719184 255.902 0 0 gcp4

After georeferencing images, the interface output a version of this file with image names and UTM data, instead of gcpN and lat/long.
Hope this helps!

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