Georeferencing Drone Imagery in QGIS

[@shubhambaranwal6950]

Great tutorial. So, basically we are georeferencing with respect to X and Y and it works for Orthomosaic. Suppose, I have DSM and I want to georeference it in all 3 directions, that is, X, Y and Z. So, is it possible with this tool? If not, do you have suggestions/advices on how to georeference DSMs with respect to Z axis.

[@maxs.8146]

Have you found a solution?

[@rezamaharlooei2400]

I couldn't find georeferencer in plugins and it is just a free hand georeferencer which is not accept ground control points

[@timd9430]

Think newer versions it's under LAYERS. Use coordinates from actual ground control points collected in field and match to ground control points in drone imagery.

[@flighttherapybullisticfpv133]

Im not sure I understand this.. What is the purpose of referencing your ortho to google sat maps if the Geotiff is already geo-referenced in Pix4d? If you used the GCP's or your RTK/PPk/PPP correctly and the data is accurate, wouldn't you be degrading the absolute accuracy of your map by referencing it to the google maps?.. Would this be for when you have no GCP's or means of geo-referencing on site?

[@DrKJoyce]

Great question! A couple of things. So it's possible to create an ortho in Pix4D with no co-ordinates at all in the first place. In my early days of droning, photos weren't automatically geotagged and we had to pair the pics with the drone log. Sometimes there were glitches, but this is rarely a problem nowadays. Secondly, the geopositioning of the drone may not be correct, so one would georeference to align it with another dataset (basemaps or even another drone dataset). Thirdly, it's not always possible to have GCPs, RTK etc. So you're correct - basically this is a technique to use when you need better alignment between datasets for whatever reason.

[@flighttherapybullisticfpv133]

@@DrKJoyce Oh ok, thanks so much for the reply! That must have been a real pain to do the photo tagging manually, you've been in this alot longer than me.. I tried something like that once trying to use video from a "naked" (stripped from its frame) gopro, to make an ortho using a sub-250g fixed wing rig with the gopro mounted in it.. It didnt work very well lol.. and I can't imagine doing that for 1000+ image jobs.

[@DrKJoyce]

@@flighttherapybullisticfpv133 Oh no, I definitely wasn't doing it manually for individual images :) So basically we can still run through the process to stitch the data without geotags, then we reference the mosaic. Way easier to reference one mosaic than hundreds of raw images!

[@loganwoolfson5823]

Hi, when I copy the URL to create my google satellite layer. My layer comes out white i.e. no detail of the new layer. Any suggestions?

[@NgheDiaChatvlogs]

have you ever use a plugin "HCM Gis", it's so easy to add Base maps!

[@wisconsindeathtrip]

The Georef plugin is not available. Did they rename it?

[@DrKJoyce]

Sorry to hear that - it seems to be playing fine for me. I don't show how to add data in that particular video though. Here's the full QGIS playlist that you might find helpful. But in short, to add the data, just drag and drop it in!

[@wisconsindeathtrip]

I found out that its already installed in the newest version and doesnt show as a plugin.@@DrKJoyce

[@joelawagasi476]

Very helpful thanks

[@HERUqp]

nice..whais presicion measure?

[@metalthower]

What software did you use to create the image mosaic?

[@DrKJoyce]

Pix4D

[@ElimelecMedina]

So, you export directly from pix4d to qgis?

[@DrKJoyce]

The output from pix4D is a geotif. I then just open it in whatever GIS or image processing software I'm using

[@ElimelecMedina]

@@DrKJoyce ok... Cool I am using qgis... That should work? Using a Easter and then georeferencing?

[@DrKJoyce]

@@ElimelecMedina I'm not sure what you mean by that, but yes, you can use QGIS

[@ElimelecMedina]

@@DrKJoyce sorry I meant to write something else and autocorrect didn't help... What I was try to say is that....how hard is it to export to qgis? Using raster? After that georeferencing?

[@DrKJoyce]

@@ElimelecMedina You don't need to 'export' per se. The output from running SfM in Pix4D is a geotif. This opens just fine in a GIS or image processing system

[@lisadoro268]

Are you an archaeologist?

[@wellingtonconstantino5607]

Muito bom