We are researching various solutions for PPK mapping and Volumetric measurement.
We are flying the Mavic 2 Zoom for inspection and have found the following solutions but wanted to know if anyone has performed any insights to these companies and their solution;
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Topodrone - Uses the M2 and provides a custom GNSS multi-band solution. Require taking apart the drone (voiding warranty)
Temini - Uses custom board and provides a custom GNSS multi-band solution. Require taking apart the drone (voiding warranty)
Metta - Uses the M2 and Emlid GNSS multi-band antenna solution. Does not require taking apart the drone, BUT its solution has a delay between photo/logging, and this could cause inaccurate data. (from my understanding and I have not verified, EXPERIENCE NEEDED PLEASE)
M2 - Using the Emlid solutions directly configuring a solution ourselves.
This is all a little confusing because three of the solutions use M2, so why wouldn’t Emlid just provide a single solution versus having to go to third parties?! Next, my understanding is some of the third parties provide actually better and more accurate solutions, but again it’s all a little confusing.
We use Teokit for P4pro, and i believe Temini would also give the best result. The telegram group is great and also the teobox (online or offline) is slightly better than ES on drone data processing, but i also believe ES will catch up on the next upgrade.
The downside of Teokit is we have to disassembled the drone. But it is worth to try.
I’m still studying and analyzing which drone solution is best for me.
So far I have come to the conclusion that Autel Evo II RTK, compatible with Emlid RS2, and unlike DJI competitors, is not limited to RTK, allowing use in PPK.
As for the other kits, the main difference I noticed is the need or not to disassemble the drone and the way in which the point is recorded, by the LED sensor or directly on the drone board.
So, I understand that it would be prudent to analyze these two points:
If you don’t want to open your drone or lose the warranty, choose a hands-free kit;
If you want more precision and less sensor delays in data collection, choose a kit that connects directly to the board;
Yeah, that’s what I came up with also, and it is something to take into consideration. With that said, I read somewhere that the delay can be “calculated for” and if you just went with it, it “could” be a few CM off if flying slow/average to up to a Meter off if flying fast… Have you heard any of this?
DJI drones do not have an easy way in which to let the M2 know exactly when an image is recorded. There is nothing Emlid can do about that. The available kits either watch for a light to blink, no taking the drone apart, but not as accurate. Or, insert a circuit into the the drone to intercept the write command which involves taking the drone apart but is more accurate.
I have not done a side by side comparison, nor have I seen anyone else do one. But that is a good idea.
More things to think about.
The flight software availability is probably best for the P4RTK and likely the M3E too, shortly because of the DJI SDK. Autel’s SDK is lacking so other developers have no way to support it properly. That may not be an issue for you if you plan on using a PPK workflow because, for some reason, you have to run the manufacturer’s flight app in order to have the rinex files generated. But the DJI drones can do RTK with other flight apps.
Currently, there is no Terrain awareness mission options for the Autel. DJI’s software is much more mature than Autels. But Autel has no geofencing if it is not mandated by your country’s rules. DJI’s geofencing does pose problems for sites here in the US occasionally.
Yeah my uses has to be PPK because we are remote mountain areas, not even a CORS location close enough to work with, let a long consistent cell/inet. This a base/rover/PPK drone situation and using a Mavic 2 with six batteries… did I mention remote? A few jobs will be hike in, camp, drone, drone, drone, camp, hike out. Regardless, it need to be PPK accurate but not LiDAR accurate.
I’m trying to find out how accurate the Mettatech led solution is, I’ve read someone mentioning it could be as far as a meter off due to the delay between the actual shutter and led trigger… has anyone heard otherwise as it’s the most noninvasive method.
Where as the TeoKit is the most integrated, recording not only the time the shot was made but camera details.
Topodrone is the most expensive but seems to be the most solid and comes with its own software (open source, skinned with their UI, but still supported by them!).
I’m still not getting a clear solution from anyone and buying a new drone, while could be an option I don’t want to spend that money if I can buy a ppk solution.
If you can afford it, go for Mavic 3E with RTK.
I use mettatec on a P4Pro and it is easy to use but the accuracy is not very good especialy if you fly fast >5m/s.
For me the best solution is Mavic 3E RTK or P4P RTK or Autel RTK with the combination of a RS2 to use as local base without the need of internet. Everything else is a hasle.
From what I’ve read, it’s not as accurate and we have to be within 5% accuracy. Additionally, there will be times that there may not to consistent or clear GCP placement. Ie. On the side of a +60 degree slope mountain.
Last month I did a side by side comparison of the Autel Evo II E RTK and the DJI Mavic 3E RTK. Same day, same site, same control and check points. Reach RS2+ was base station for both flights. Will try to document it on other forums.
Short answer is that from a mapping quality standpoint, there is very little difference between the two systems. However, the DJI is substantially faster and more efficient.
Just wanted to leave a short summary from the Reach perspective:
As Dave said, there’s no straightforward way to connect Reach M2 to drones without a hot shoe on the camera. If you work with such drones, you can collect GCPs with a pair of Reach receivers. It helps improve the accuracy of your model or orthophoto.
Reach RS2+ works as a PPK and RTK base for different RTK drones. You can find the integration guides for DJI and Autel in our docs.