Litchi waypoint question.

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Question re Litchi waypoint height Above Sea Level (ASL).
I live in a quite hilly area and I am trying to understand waypoint flying.
The Litchi manual states"Altitude: The altitude of the waypoint relative to the elevation of the aircraft where it was powered on.

If I set my aircraft at waypoint 1, which is at an elevation of 230m ASL , to 30m, the aircraft will rise to an elevation of 230m + 30m = 260m.
If I then fly to waypoint 2 keeping the waypoint altitude to 30m and waypoint 2 is at 250m ASL, what will the height of my aircraft be at waypoint 2 releative to the ground?
 
What Jayfdee said. Label is a bit misleading. It would have been better if DJI had used 'height'. everything is referenced to the take off location. That point has a 'height' of 0. All readings in the apps are then how high the bird is above (or below) that point. Note some apps allow you to move the home location, but that doesn't reset the reference height. It is still referenced to the take off point.
 
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What Jayfdee said. Label is a bit misleading. It would have been better if DJI had used 'height'. everything is referenced to the take off location. That point has a 'height' of 0. All readings in the apps are then how high the bird is above (or below) that point. Note some apps allow you to move the home location, but that doesn't reset the reference height. It is still referenced to the take off point.
The question was "what will the height of my aircraft be at waypoint 2 releative to the ground?", not sure how I was misleading, but you do give a fuller explanation, so I was a bit curt in my response,apologies.
 
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The latest version of Litchi can group-edit all waypoints to be referenced to ground, although 'ground' is still considered to be the takeoff point.
 
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The latest version of Litchi can group-edit all waypoints to be referenced to ground, although 'ground' is still considered to be the takeoff point.
I would use with caution at the moment, I am guessing it is using the Google earth data, rather like planning a mission on Google earth relative to ground, and uploading the data to Litchi, but cutting out the saving of the file from GE, and uploading to Litchi. I will investigate and experiment, thanks for posting, I was unaware of this development.
 
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Well yes, the auto adjustments to ground will be only as good as the terrain database. I would expect that to be accurate enough for general flying as long as you use a reasonable fudge factor as one should always do with altitude settings, although I wouldn't count on it for precision work. But it should be just as good as using Google Earth for planning and then exporting/importing data (since the database is the same), but it's now much easier to do it in the app.
 
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They didn't say *you* was misleading, they said the *label* was misleading.
Right, I was referring to the label that DJI used, not the OPs question. Pilots use altitude in msl and height (agl) to refer to distance above the ground or obstacles. We fly our phantoms using the distance above the Homepoint so height.
 
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I speak from experience, very important advice was already given on fudging on wp alt, fly the mission, then adjust alt at each wp based on the video if needed. Especially those missions that go beyond controller range.
 
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I speak from experience, very important advice was already given on fudging on wp alt, fly the mission, then adjust alt at each wp based on the video if needed. Especially those missions that go beyond controller range.
Thank you.
Yes I have planned to plot a mission at maximum safe height above start point (~400ft) and examine waypoint height at each waypoint.
Each waypoint may then be adjusted for height above ground for the main mission.
It all can get very confusing especially in hilly terrain but practice will prevail, I feel sure.

Regards, John..
 
AC Height is generally determined by barometer readings relative to takeoff reading, which essentially is a constant offset to sea level.
So if you fly up 10 feet, then climb a 10ft hill, you should then show an altitude of 20ft even though you are still 10ft above the ground just below the AC.
GPS can also be used to determine altitude but isn't very accurate.

Sent from my HTC 10 using PhantomPilots mobile app
 
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AC Height is generally determined by barometer readings relative to takeoff reading, which essentially is a constant offset to sea level.
So if you fly up 10 feet, then climb a 10ft hill, you should then show an altitude of 20ft even though you are still 10ft above the ground just below the AC.
GPS can also be used to determine altitude but isn't very accurate.

Sent from my HTC 10 using PhantomPilots mobile app

Ok Chaps, I think the best way is to do a flight and test what is going on,
I have written a spreadsheet to do the calculations and will post results when weather clears up.

Regards, John.
 

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