Offset generated orthophoto


#1

Hello,

We are using OpenDroneMap for a while but we have a issue that the generated map does not overlap correctly over google maps.
In the screenshots below you can see what I mean. In the first one there is a lane of crops but it is not on the correct spot. In the second image the road on the left is good but on the top it is not on the good location.
Is there a way to offset the map so it is on the correct location?

We are using the LiveODM installed on a server.

Also a side thing. Is it possible to zoom in more, both in ODM and with google maps api



#2

Hey @natsuki-chan :hand: have you tried using a ground control point file? https://docs.opendronemap.org/using.html#ground-control-points


#3

The challenge here is multi-fold – we don’t know what the offset or spatial error is in google maps (it could be 3 meters, it could be 10, it might be less than 1 meter); compounding this issue is the GPS on your drone which, unless it’s something special, is around 5-10 meters 95% of the time (and even greater error on 1 out of 20 days).

There are a couple approaches for dealing with this. One is to use a ground control point file either derived from surveyed points or from the imagery you are trying to match. Another is to consider it part of the error of doing this without high-quality GPS. But, probably the easiest compromise is to use the QGIS Georeferencer Plugin in combination with the OpenLayers Plugin to post-process your data to match the Google Maps imagery.