DJI Mavic, Air and Mini Drones
Friendly, Helpful & Knowledgeable Community
Join Us Now

Max altitude

Most light aircraft don't have the ability to tell AGL height because a radar altimeter is expensive and not particularly necessary.
They use a barometric sensor just like your drone does.

But if you want to get a nice economical radar altimeter for your drone, here's a good deal on a secondhand unit.
With the antenna, it weighs 3 pounds and you will need to find a 28 volt power supply to run it.
Sarcasm would be more effective against someone who had not already pled ignorance on the subject. But kudos on your knowledge.
 
  • Like
Reactions: Rocket 3 GT
Almost any airplane on the planet can tell the AGL, it would seem not terribly difficult to incorporate that into drones. But I do admit I am not very knowledgeable on this. I am so ignorant I dont even know what DEM is, lol.
That's because they have a Radar Altimeter. They are expensive, large, heavy and not "Consumer Drone" compatible.

Granted there are some "UAV Radar Altimeters' available but they are still expensive (least one we've looked at was $699) and the few I've looked at still won't work because their MAX range of 50M in ideal conditions.
 
As I already stated I plead ignorance. But somehow I think a smaller one could be managed. The old computers used to take up warehouses, now a micro SD card can hold the equivalent data. But I guess that might be why drones don’t have that capability.

In time the tech will catch up. It's come a LONG way in just the last couple of years. I'd guess in the next 10 years we'll see Radar Altimeters that size of a matchbook and weighing under 25grams. The price, that may not come into play with what we are willing to dish out for our consumer drones.
 
Maybe I'm not understanding english too good - If i fly off a cliff I start where I'm standing so say 2m - or basically eye level - as I fly off the cliff the drone is now 1000m up as the ground has dropped away. If I fly to the bottom of the cliff will I be able to fly back up again?

Different situation where I am at the base of a hill and want to fly up the slope to the top, say 1000m. the high above ground is only say 50m, but the height from the starting point would be much higher as you are progressing upwards.

Sorry if this sounds stupid, but i fly in a very flat area, but will be going to quite a hilly area shortly.
 
If i fly off a cliff I start where I'm standing so say 2m - or basically eye level - as I fly off the cliff the drone is now 1000m up as the ground has dropped away. If I fly to the bottom of the cliff will I be able to fly back up again?
The drone tracks the current altitude like this:

1698509358381.png

After you fly above the takeoff point and reach the maximum allowed altitude, you will no longer be able to ascend. There is no limit to how low you can fly beneath the takeoff point.
 
Maybe I'm not understanding english too good - If i fly off a cliff I start where I'm standing so say 2m - or basically eye level - as I fly off the cliff the drone is now 1000m up as the ground has dropped away. If I fly to the bottom of the cliff will I be able to fly back up again?
Your drone is a flying machine.
It would fly back up again, just like a bird or a helicopter could.
 
Your drone is a flying machine.
It would fly back up again, just like a bird or a helicopter could.
I think the caveat is the poster was asking about an altitude restriction which birds and helicopters don't have. If the poster flew his altitude-restricted drone to the bottom of that mountain and he "landed" then he would be unable to take off them there and fly it back to the top of the mountain. Maybe I'm not following the conversation closely but that's what I thought he was saying.

A hardcoded max altitude of 120m above take off point for a mini drone is a bad, bad idea.
 
I think the caveat is the poster was asking about an altitude restriction which birds and helicopters don't have. If the poster flew his altitude-restricted drone to the bottom of that mountain and he "landed" then he would be unable to take off them there and fly it back to the top of the mountain.
Where did you get the idea that his drone is "altitude restricted"?
A hardcoded max altitude of 120m above take off point for a mini drone is a bad, bad idea.
You don't have a hard wired max altitude or 120 metres above launch spot.
The person you are referring to doesn't either, so what does that have to do with the discussion?
 
Where did you get the idea that his drone is "altitude restricted"?

You don't have a hard wired max altitude or 120 metres above launch spot.
The person you are referring to doesn't either, so what does that have to do with the discussion?
Oh ok, I might be in the wrong thread. I thought this was the discussion about the 120m/500m restriction. :)
 
I flew the Dji Mini 4 Pro to 10,000 Feet above ground! Watch the video here!
If that truly was in Virginia, not the best thing to do for a few reasons.
The first reason would be that the FAA would have a few things to talk with you about.
The other reasons will show up here later.
 
  • Like
Reactions: Ardenkablam
If that truly was in Virginia, not the best thing to do for a few reasons.
The first reason would be that the FAA would have a few things to talk with you about.
The other reasons will show up here later.
The poster says:

"You can do this yourself by getting FAA Authorization then submitting an unlock request at Dji."
https://fly-safe.dji.com/unlock send an unlock request for your area. You will need to get FAA authorization.

Is he lying?
 
My thought is that DjI with todays technology could make monitoring the AGL a thing. Maybe in a future model.
Go to the closest general aviation airport and ask someone to show you the instrument panel on the hottest prop-driven airplane there. You'll almost certainly see a barometric altimeter, the same technology used in our drones, with no means to measure AGL altitude. Anything more sophisticated, like a radar altimeter, is simply too expensive, too heavy, and too complex for the application.

If DJI had a ground-sensing altimeter that fits in one of their drone models, they'd be selling them like hotcakes for commercial aviation and military use.
 
Last edited:
The poster says:

"You can do this yourself by getting FAA Authorization then submitting an unlock request at Dji."
https://fly-safe.dji.com/unlock send an unlock request for your area. You will need to get FAA authorization.

Is he lying?
I did watch the video in post number 35 and did not see or read that information.
Did I miss something?
 
I flew the Dji Mini 4 Pro to 10,000 Feet above ground! Watch the video here!
Your youtube post includes this note.

"Flew the new Dji Mini 4 Pro to 10,000 Feet! I was terrified while doing this! You can do this yourself by getting FAA Authorization then submitting an unlock request at Dji."

Did you actually receive an FAA airspace authorization for that flight?
 
Lycus Tech Mavic Air 3 Case

DJI Drone Deals

New Threads

Forum statistics

Threads
130,112
Messages
1,549,402
Members
159,168
Latest member
hubb43