Litchi altitude

In response to Ambivalent Squirrel's questions in general (Litchi aside), if you start your HP (Home Point) at the top of a cliff, then fly over the cliff and descend, you will get a negative altitude number in the DJI Go app.

It looks like folks are saying that the Litchi app won't allow that in respect to programming waypoints, but in general, that's what happens when flying: all altitudes are relative to the HP.

Chris

PS: Ambivalent Squirrel would make a good band name!

:) band name. I like that
 
I hate to see ads on Mission Hub :) Ready to donate $5 to get rid of them.
 
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Apart from the terrain, when you pick a waypoint, it gives you its elevation and relative difference with waypoint 1
ImageUploadedByPhantomPilots1461998094.991399.jpg
 
well that was "fun"

plotted a little mission in Litchi. Flew it no problems.

The decided to have a look at the 'tracking' option. Working just fine, tracking a small statue... flying away from it, phantom at about 30ft. Phantom goes over edge off cliff, and I'm no more than about 50ft away from it.

Phone video feed goes black, "signal lost" phantom goes into a hover. Not responding to sticks. oh oh...

red light on main controller. phantom is close enough to see flashing yellow lights (lost RC signal?) Phantom stuck in hover... oh man. if it comes down here, it's going to try and land on side of cliff :-(

anyway after a long couple of minutes, it eventually responded to a toggle on the side switches to kick in the RTH.

scary :(
 
well that was "fun"

plotted a little mission in Litchi. Flew it no problems.

The decided to have a look at the 'tracking' option. Working just fine, tracking a small statue... flying away from it, phantom at about 30ft. Phantom goes over edge off cliff, and I'm no more than about 50ft away from it.

Phone video feed goes black, "signal lost" phantom goes into a hover. Not responding to sticks. oh oh...

red light on main controller. phantom is close enough to see flashing yellow lights (lost RC signal?) Phantom stuck in hover... oh man. if it comes down here, it's going to try and land on side of cliff :-(

anyway after a long couple of minutes, it eventually responded to a toggle on the side switches to kick in the RTH.

scary :(
Its FUN but scary when you have a feeling of loosing it. I believe you were running at a bad site. Move somewhere else.
 
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Apart from the terrain, when you pick a waypoint, it gives you its elevation and relative difference with waypoint 1View attachment 52132
Minor quibble here: All waypoint heights in Litchi refer to height above the Homepoint (not relative to waypoint 1).

Because it works that way, you can basically copy a mission and plant it anywhere on the earth. The heights are always relative to where you start up the Phantom.
 
Minor quibble here: All waypoint heights in Litchi refer to height above the Homepoint (not relative to waypoint 1).

Because it works that way, you can basically copy a mission and plant it anywhere on the earth. The heights are always relative to where you start up the Phantom.
You are right.

There are various terms and people get confused:
Height
Altitude
Elevation

We use Altitude word here to show what will be the flying height wrt to home point. (AGL)

Elevation is height of ground wrt to sea level (ASL)

Difference in elevations at two consecutive waypoints will tell you how does the clearance of aircraft changes wrt to ground.

At the time of planning, you don't know the home point, so Litchi at least references elevations of other waypoints wrt to first point.
 
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At the time of planning, you don't know the home point, so Litchi at least references elevations of other waypoints wrt to first point.
But it doesn't.
Litchi shows the height of W1 relative to home, W2 relative to home, W3 relative to home etc.
Waypoint 1 is just another waypoint and nothing is shown as relative to W1.
 
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But it doesn't.
Litchi shows the height of W1 relative to home, W2 relative to home, W3 relative to home etc.
Waypoint 1 is just another waypoint and nothing is shown as relative to W1.
See the elevations of each point after opening the details of each. You will see it shows elevation wrt to waypoint 1

Yes it shows two values at each way point: 1. how high it will be flying when it reaches that way point wrt home point and 2. how the ground clearance will vary at that waypoint.

(if you are on tablet or phone, you will see only flying heights wrt to home point. Use laptop/ Mac and open Mission Hub for details)
 
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See the elevations of each point after opening the details of each. You will see it shows elevation wrt to waypoint 1
Yes it shows two values at each way point: 1. how high it will be flying when it reaches that way point wrt home point and 2. how the ground clearance will vary at that waypoint.
I'm no sure what yours shows but mine only shows the altitude which is relative to the home point
i-5q2nLmB-L.png
 
I'm no sure what yours shows but mine only shows the altitude which is relative to the home point
i-5q2nLmB-L.png
Check on Mission Hub on laptop/ Mac. See my post #23
 
Check on Mission Hub on laptop/ Mac. See my post #23

That's actually a perfect example of where people get confused. Waypoint 1 with a "height" of 98 feet is located on the 600 foot elevation line. So it seems logical that W1 is at 698 feet altitude. But it's not. It depends on where you take off from.

In your example, if you take off from around Discovery Way (400 foot elevation, but zero height since it's the homepoint) the P3 will climb to 498 feet altitude on its way to W1. It will crash on its way there since it's 100 feet too low (below the actual 600 ft elevation).

No matter where you set up your route: phone, tablet or mission hub; the waypoint height number is always relative to where you take off from.
 
But it doesn't.
Litchi shows the height of W1 relative to home, W2 relative to home, W3 relative to home etc.
Waypoint 1 is just another waypoint and nothing is shown as relative to W1.

Meta,

Maybe it has something to do with Litchi's online mission hub. I've been flying with Litchi since it's inception but have not used mission hub. Your description is correct in every mission I've ever flown. All waypoints are relative to home not any other waypoint.

Jerry
 
I hate to see ads on Mission Hub :) Ready to donate $5 to get rid of them.
Me also. I'm not sure if anyone else has noticed but, when using Mission Hub on an iPad, it doesn't appear to be possible to actually open one of your own missions. When I click on Missions and then the "open" option, it simply opens the ad which has its link in the same area.
 

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