can AGL be added to the Mavic Mini for better safety? It would help to see how far off the ground you are with changing terrain.

Good idea. Probably need active internet to get this info.

Guorium Posted at 5-12 14:24
Good idea. Probably need active internet to get this info.

Maybe, but there are sensors on the bottom of the Mavic Mini

No, because it requires a very expensive, bulky and heavy sensor to work out the height above terrain. The sensors on the bottom of the aircraft are only good for a maximum height of 30 Metres above the ground. And no, having the Internet will not solve the problem.

NatureDigital Posted at 5-12 14:32
Maybe, but there are sensors on the bottom of the Mavic Mini

Read the specs for the Mini.
Sensing System
    Downward
    Operating Range: 0.5-10 m

Guorium Posted at 5-12 14:24
Good idea. Probably need active internet to get this info.

How would that be of any help?

In Google Earth, I can hover over anyplace, and a display at the bottom right shows the ground elevation at that point.  It's not super accurate, but not bad usually.

Presumably, with an internet connection, or if you had a map (with ground elevations, like a topo map) stored in memory, with the GPS coordinates, the program could know ground elevation, and with the altimeter in the drone knowing altitude with respect to the take-off point, the program could calculate height AGL.  At least approximately.

The map would need to be up to date, and buildings, etc., would likely be unknown.  So how useful?

A friend has a commercial fishing boat in Alaskan waters.  He subscribes to a service that maintains an up-to-date database for undersea "topography".  Shoals and the like can change quickly.  Used with his GPS, it displays real time maps of what's below him.  Between that and sonar as a backup, as well as radar for surface objects, he can navigate in darkness and total fog, etc.   

Sigmo Posted at 5-12 17:49
In Google Earth, I can hover over anyplace, and a display at the bottom right shows the ground elevation at that point.  It's not super accurate, but not bad usually.

Presumably, with an internet connection, or if you had a map (with ground elevations, like a topo map) stored in memory, with the GPS coordinates, the program could know ground elevation, and with the altimeter in the drone knowing altitude with respect to the take-off point, the program could calculate height AGL.  At least approximately.

It's not super accurate, but not bad usually.
It's  "accuracy" is rough and variable.  It has no information on trees or buildings etc.
It's not what you would need for safe flying in many areas.
And it's no help for drone flyers since no flying apps can use it.


A friend has a commercial fishing boat in Alaskan waters.  He subscribes to a service that maintains an up-to-date database for undersea "topography".  Shoals and the like can change quickly.  Used with his GPS, it displays real time maps of what's below him.
Sounds like you are describing Navionics "Sonar" charts which are only as good (or bad) as what has (or hasn't) been recorded for the area.

And the topography does not include any outliers or other obstacles. I use Navionics "charts" on the MFD in my boat but would never trust it to keep me from hitting a submerged obstacle. Only the live SONAR works (somewhat) for that.

Labroides Posted at 5-12 16:29
Read the specs for the Mini.
Sensing System
    Downward

Ok thanks...

Sigmo Posted at 5-12 17:49
In Google Earth, I can hover over anyplace, and a display at the bottom right shows the ground elevation at that point.  It's not super accurate, but not bad usually.

Presumably, with an internet connection, or if you had a map (with ground elevations, like a topo map) stored in memory, with the GPS coordinates, the program could know ground elevation, and with the altimeter in the drone knowing altitude with respect to the take-off point, the program could calculate height AGL.  At least approximately.

Sigmo Posted at 5-12 17:49
In Google Earth, I can hover over anyplace, and a display at the bottom right shows the ground elevation at that point.  It's not super accurate, but not bad usually.

Presumably, with an internet connection, or if you had a map (with ground elevations, like a topo map) stored in memory, with the GPS coordinates, the program could know ground elevation, and with the altimeter in the drone knowing altitude with respect to the take-off point, the program could calculate height AGL.  At least approximately.

Great. Now we all have to worry only about hitting the ground, not anything else? Someone is a member of the Flat Earth society ;-)

NatureDigital Posted at 5-12 18:33

Flying your drone, you have to do what the pilots of most small planes do.
Use a little mental arithmetic, look at your charts etc and work out how high you are.

Litchi has a similar function but does not work with the Mini as of yet.

Sigmo Posted at 5-12 17:49
In Google Earth, I can hover over anyplace, and a display at the bottom right shows the ground elevation at that point.  It's not super accurate, but not bad usually.

Presumably, with an internet connection, or if you had a map (with ground elevations, like a topo map) stored in memory, with the GPS coordinates, the program could know ground elevation, and with the altimeter in the drone knowing altitude with respect to the take-off point, the program could calculate height AGL.  At least approximately.

"Between that and sonar as a backup, as well as radar for surface objects, he can navigate in darkness and total fog, etc. "

I have a large boat, and I don't think I would put it that way. If I could only have one, I would rather have my depth gauge (sonar) than GPS. You need charts, but when in shallow waters my eyes are on the depth gauge as much as the chart.

The ESTM data used by google is not accurate enough to be used.