Litchi Mission Hub Waypoint Settings Question

[AIRn8]

Mavic Air, trying to film a quarry, so I have some POIs that are on the water. The ground there is technically way lower than the waypoint which is on land. My question is what is the point of reference for the altitude if the above ground box is not checked in the waypoint settings? I know when it is checked it is using the actual ground below it as the reference point but what about when it is not checked what is the altitude reference point then?
Thanks in advance.

 

[gerrymad]

I believe it is relative to the starting point of the flight. I pre-programmed some flights in the Alps. I was at about 1,500 feet above sea level. In my first test litchi mission I set the altitude of my first waypoint at 30 feet. When I flew the mission it started off at 30 feet above my take off point and then for the rest of the mission it operated exactly as I wanted it to do moving up and down according to the waypoint settings. I never specified above ground level.

 

[AIRn8]

OK... Cool... Because like I said I have a mission going over water so... the ground goes lower than the waypoint ground and that is messing me up cause if I do 35 from the ground in 50 feet of water then my drone becomes a sub... I wish I knew what height the water is from the ground its on? LOL! That is crazy that in the alps you did not have to do it from the ground? Were you flying in a relatively level part of the alps? Also I am dealing with POIs so you think the POIs altitude starts at the waypoints ground elevation, when the above ground box is not checked?
Thanks again!

 

[AIRn8]

The other thing is when you click the above ground box it shows you a second number that is the amount in feet you are above or below the first waypoint...?

 

[AIRn8]

Also, on the first waypoint, you have the option to check or not check the above ground box? it defaults to not checked!