What does georectification actually do?
I haven't made use of this feature yet, but would like to understand what georectification really lets me do. I get that it enables me to increase flight-to-flight precision in the same location, but does it help with accuracy?
That is, does it shift the coordinates recorded in the drone's media output? That would be pretty sweet.
Then one could set a destination to a surveyed benchmark location, hover, pause, correct the drone position over the mark, and then proceed. Then the location written to photos and video would be "calibrated" for the next 10 minutes or so. Then, after making a 2d/3d map, it could layer-in closer to the truth.
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More info here: https://support.dronelink.com/hc/en-us/articles/4416141457171-How-to-Enable-Drone-Offsets-Mission-Alignment-Georectification-
Unfortunately, it does not affect the exif data as the DJI SDK gives no access to this.
Okay, thanks.
So, in the mapping mission context, it doesn't change recorded position accuracy(like RTK), but it could help with actual drone position accuracy. The resulting map output could then be "georectified", like a poor man's PPK, if the person records what the direction and offset were.
For non-mapping uses, this feature really has the potential to improve the output in some projects, with minimal effort.
Neal McConnell
This video might help https://youtu.be/34jYPRAmN1Y?si=ykfJ19Vj0zWHk04o
Thanks, Barry. I watched that video before, and pretty much all of your videos.
I was thrown off at 1:50, because you say you use the corner of the parking lot, but later, before correction, the purple marker is not actually placed in that corner. I also didn't see the result of the correction place the drone or the home marker in that position. In this way, the action and result is not straightforward to me.
I guess I'll just have to test it out to really understand.
Hi Neal,
I'll try to explain.
I placed the marker on the corner of the lot. That is also where I will place the drone. You can see that the marker (purple) was placed on that corner at 1:30.
Don't be confused by the fact that at 1:43 the drone actually shows somewhere else. That's actually the whole point. The drone WAS placed at the corner but, because of the GPS error, the drone icons shows somewhere else. The difference between where the drone THINKS it is, and where it actually is when placed on the marker, is what is measured and used to adjust the flight.
You may be confusing the marker (shown at 1:30) with the home point (shown at 1:50). The home point is where the drone thinks it was at the point that it had enough satellites to mark the home point. That will be close to where it is...but not exactly where it is.
Hopefully that helps.
It helps, but nothing compared to just getting out and doing it. When I tried correcting on the ground, the drone's GPS location seemed to drift around, making for a moving correction target.
The interface has changed slightly since your video, and the availability of the controls is more than that recent document states. I can access the controls when in manual control, which seems like a bug, unless the offset transcends missions runs.
There was also a time, after mission completion, when map view filled the screen, but I could not get back to camera view directly.
100% agree that learning by doing is so much better. I try things out all the time - it's sort of how half of the 5MF videos came about when I would see something and go "hmm...that's interesting..."
Yes, the interface has also changed. This is a constant problem. I have videos that are really outdated now because the UI has changed, but the concepts are still there so I leave them up. At least until I can find time to replace them with a new version.
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