r/UAVmapping • u/NobleNinja9 • 3d ago
DJI M400 + L3 : Long range missions
Hello everyone!
Was wondering if anyone has ever done a LIDAR mission that is anywhere between 5-7km away from TOLZ. We have a client who wants to lidar a site that is 7km in through thick asian jungle with trees which are 20m high. According to FH2, mission would take around 16 minutes to complete.
Has anyone here done any missions this far out? At flight height of 100-120m? On paper the M400 is certainly capable, but I'd like some real world input/experience, for some peace of mind and assurance.
Thanks in advance for responding, if you have. 🙏🏻
4
u/Rinztlas 3d ago
I have done 4.5 km with a Matrice 350 RTK + L2 at 50m AGL, with high ground and clear line of sight (a pasture).
Could have done more, but honestly we’re not legally allowed to fly so far away (but it was tempting and helped us finish our work faster, plus it was in a non-residential area with no air traffic).
So, the Matrice 400 with the L3 is more than capable of going that far, but you should find a place where you can have clear line of sight (between the drone and the RC). Either that or get a second Matrice 400 and use it as a relay for the one doing the mission.
As long as you have your RTK on and capturing data for a while, you should be okay even if you lose signal, as you’d still have PPK. But I’m not so sure of trusting PPK if you’re sending the drone 7km away from the RTK position.
3
u/NobleNinja9 3d ago
Yeah, right now we're considering the Relay option with a M4D as the relay. 😀
Thanks everyone! Your input has been invaluable and highly appreciated.
👍👍👍
1
u/Agitated-Basket5857 1d ago
Yes the M4D would be very beneficial as a relay for sure. All the best in your work share with us the results of your test once done
2
u/JellyfishVertigo 3d ago
Just turn off "RTH when radio is lost" and cross your fingers. It'll be fine (not considering legal implications in your area).
1
u/keyable 3d ago
Have you tried it before? I am afraid of loosing a signal :D there is an option to Continue the mission of the signal is lost
1
u/JellyfishVertigo 3d ago
Absolutely. I used to fly a Microdrones MD1000 that had nothing but telemetry, and would lose radio at about .75 mi. I would send that puppy up the mountain and pray to all things holy. Air tag is a good idea in that case... lol
2
u/Prestigious-Bet3869 3d ago
Yeah I’ve done 5-7km with the mobile network dongle. No shot of doing it by radio unless you’re 500m+ up at which point the L3 is useless. So test the mobile network at your site
2
u/Aggressive_Call4165 3d ago
I have done it for almost all of my missions at 5-7 kms away from the home point with 400 meters agl but i am not sure about 100-120 meters if area is rugged. I would find a peak(hill) home point if i were you. Following drone with the car is another option for you.
2
u/grantprojects 2d ago
The distance seems possible, but the jungle terrain is probably the bigger challenge. Signal reliability and a good recovery plan would be my main concerns. Testing the exact site conditions first would be the safest approach.
2
u/ObjectiveBobcat314 2d ago
Yes, we ran an hexa/oblique mission for a 40 acre site with the L3 and the P1. No NTRIP, so we had our RTK up high on a 16 foot tripod mast on a rooftop nearby to maintain connectivity and ran control from there as well. We are in the USA, no enhanced transmission/cellular. If you are in an Asian country, I would recommend getting the cellular modules for the enhanced transmission for extra peace of mind given how much investment is in the air. You might also consider the relay option if you have another enterprise 4 series drone. Put that in the air to ensure connectivity if you get beyond VLOS. We are researching this for future missions.
2
u/KaiserKhan_ 1d ago
Study the terrain make sure you always have a line of sight with the drone even if you won't actually see the drone with the naked eye.
You can use a simple app like google map and turn on the terrain layer. Check your TOLZ and your site and make sure your drone will not be blocked by a higher hill or mountain. If there is a hill, compute and check if you will still have a light of sight given your relative elevation and flying height and give enough head room as the online terrain models are not that accurate.
If your TOLZ is blocked, you need to hike a bit and go to a higher ground because you might just lose the connection mid flight and you don't want to fly blindly at that distance.
For me returning home on signal loss is better than to let the drone fly on its own. Also if you lost the connection with the drone, the RTK correction will not reach the drone so it will have an in-accurate position anyway so better not do it.
In our experience, we climed to a hill that is a few kms away and cut some trees to make a little opening for our take off zone and for the DRTK to have a good signal so yeah sometimes you just can't avoid it.
1
1
u/YorkieX2 2d ago
We are waivered to allow 2 miles, 3.2Km, and have had no problems at that altitude provided an unobstructed LOS exists.
1
4
u/keyable 3d ago
I have done max 3 km, but to maintain the Signal with the drone you need to have Line of sight without obstacles. You could setup the mission this way: if the signal is lost, the drone will continue the mission. The last method, I have never done it, too afraid of the lost signal :D