How accurate is Litchi HT and distance measurements when flying?

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I have just started using Litchi on phantom 4 pro . When I fly with the voice telling me the ht and distance and speed. It appears that the actual measurements are way off. I was flying at 2 ft and it said I was 9 ft high. And this happens with distance as well as speed. At first I thought it was from the lag time that the voice reports the measurements which I set at 20 seconds. But I let the drone stay in position for more time and I keep getting the errors on the hight and distance and it is way off. Is this normal for Litchi or is there a setting I missed.
 
I have just started using Litchi on phantom 4 pro . When I fly with the voice telling me the ht and distance and speed. It appears that the actual measurements are way off. I was flying at 2 ft and it said I was 9 ft high. And this happens with distance as well as speed. At first I thought it was from the lag time that the voice reports the measurements which I set at 20 seconds. But I let the drone stay in position for more time and I keep getting the errors on the hight and distance and it is way off. Is this normal for Litchi or is there a setting I missed.
It makes no difference whether you use Litchi or DJI Go 4, the distance and height measurements come from the same sensors and are exactly the same.
Distance comes from GPS and should be very close (+/- 10 ft).
Height comes from a barometric sensor and you commonly see drift of 10 ft or more over the time of a flight.
Height is height above the level of the launch point, not height above the ground below.
You always need to allow a comfortable margin between your drone and obstacles or the ground.
 
It makes no difference whether you use Litchi or DJI Go 4, the distance and height measurements come from the same sensors and are exactly the same.
Distance comes from GPS and should be very close (+/- 10 ft).
Height comes from a barometric sensor and you commonly see drift of 10 ft or more over the time of a flight.
Height is height above the level of the launch point, not height above the ground below.
You always need to allow a comfortable margin between your drone and obstacles or the ground.
Ok great that explains it, im not good at the app stuff and specs, i just try to fly without crashing, so i watch everything the screen tells me to assist in were the drone is. It was the first time i use Litchi voice reply and it really thru me off ,thanks
 
Also even if you program your Litchi flight to maintain the drone's altitudes above each waypoint as it is crossed, meaning above the terrain at the drone's current position along the flight path, as opposed to having altitudes referenced to the launch point, the audio altitude callouts will always be referenced to the launch point, and not to the current location of the drone along its waypoint flight path.

This means if, for example, you set a fixed altitude of 150 feet above terrain level, flying the drone over land that lies below the launch point will mean that those periodic altitude callouts will be LESS than the pre-programmed 150 feet AGL. Litchi tends to fly the drone a tad higher than specified when the flight path is vectored over lower-lying terrain than the launch point.

It is well worth mentioning also that if the drone's waypoint mission takes it over terrain whose altitude is higher than the launch point, Litchi tends to fly the drone significantly LOWER than the altitude that was specified in creating the waypoint mission, which could result in the drone hitting a tree or building if that margin of error is not factored in during the creation of such a flight path.

But for the saving grace of my Mavic Pro's collision avoidance safety net, I would have lost that drone to a palm tree looming just 50 feet high during a waypoint mission flown some time ago, despite my having set the altitude to be 150 feet above ground level at the drone's position along the flight path. Had I flown my Phantom 3 Standard along that same route, it would have careened into that tree for sure, since that old drone has no obstacle avoidance features.
 
Use Virtual Litchi Mission in Google Earth. I run the mission several times before the actual one, plus move the cursor over the entire route noting the altitude that Google Earth reports. Add a margin for safety and away we go.
 
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In usual flights, such minimal distances or deviations are not very important. When the drone is close to you you will estimate the distance or the height with your eyes more accurately.
When the distance increases (a few hundreds of m) you want to have more than a few m tolerance in distance or in height (at least 10m or more). With increasing practice, you'll become more accurate in estimating distances by the live view of the camera but even then it is not wise to get closer than 2m from an obstacle.
When I fly over trees I usually fly at least 5m, or better 10m, above them.
 

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