high altitude drones
I have a project that is located at 3500+ m elevation. I am trying to find out which drones can fly that high, but the discussions have all been about "you can't fly higher than 400 feet". Of course, I would still keep the drone relatively close to the surface, but how well can they fly at that altitude? The small planes I fly have a lot of trouble climbing above 3500 m, especially on a hot day (high density altitude).
So I am not talking about flying high above the ground, just flying normal altitude above the ground at a location that has a very high ground elevation.
It's called density altitude. You can probably find some charts that you can use for this. You have to input the temperature and humidity. When I flew helicopters this was a standard pre-flight item to make sure you had the power you need when flying at altitude, and in particular hovering. Higher and warmer means much less dense air and less volume for the blades to work with to create lift.
For any particular drone, look up the Max Service Ceiling. For the Mavic, I think it it 5000m, so probably similar for other, though some have high altitude props available.
There are high altitude props for DJI Inspire 2's that they claim can go up to 5000m. For s stunt someone did a video of an eBee near the top of the Matterhorn.
Depending upon exactly what the job is, one of the QuestUAV fixed wing aircraft may be what you need. We use a standard Q200, but they do high altitude versions of both that and the Datahawk which have flown at similar altitudes to your requirement. They will customise to suit needs (we are currently assisting them on a project integrating a multispectral camera with PPK for use over shallow water). The aircraft comes in a modular form for easy transport, so it is straightforward to use either standard or high altitude wings (but not one of each!!)
Contact is Stuart King : firstname.lastname@example.org
The advantage of a fixed wing, especially at altitude, is that you need considerably less power out of the battery so flight times are much longer - typically we can push 50 minutes at sea level with our standard one. They have sold several to Kazakstan area - heights around 7000ft. I think those were standard models.
As regards flying height, if the accuracies you want will permit then applying for a height exemption is worthwhile. I was very surprised at how much quicker the area was covered on the multispectral trials when it was flown at 800 ft. AGL, still with good resolution. The Q200 comes with a 24mp Sony as standard.