Q's re: height telemetry variance and connection loss behavior

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How accurate is the barometer for measuring height? If within wireless signal, does the aircraft take topography into account to report AGL height? Or is it simply a blind difference in assumed height between the aircraft and the starting position?

It seems like barometric pressure is a wildly innacurate way to measure small changes in height, especially where there is changing air velocity and prop wash.

Also, I experienced a connection loss yesterday while flying in hilly terrain and accidentally going behind a ridge. The aircraft stopped and retraced it's flight path until connection was reestablished. Not wanting to accidentally go suddenly out of signal range again, I used RTH to establish a direct heading to home, and then retook control of the aircraft.

My current settings are to initiate RTH on connection loss, but that's not really what happened here. Will this retracing of the flight path always occur? Are there settings I can choose to encourage this behavior?

When I did select RTH, the aircraft didn't drop to my specified RTH height. Does the aircraft only use the specified height if a climb is required to attain that height?

Finally, the manual that shipped with the Phantom was very brief, and the tutorials seem extremely basic. Is there better documentation available so I don't have to bother you guys with questions like this? If so, feel free to just point me there and tell me to RTFM rather than take time to answer all of my questions.
 
Excellent! Thanks so much, this is exactly what I was looking for. Strange they don't include this manual in the box.
 
Excellent! Thanks so much, this is exactly what I was looking for. Strange they don't include this manual in the box.
A lot of tech companies don't include full manuals any more, just quickstart guides. Apple is an example that comes to mind. With software updates and so forth, printed manuals can be out of date before the product is opened.
 
Forgot to add.. Take off point is taken as zero, and all heights shown are relative to that.

This is true. Double check your alt readings when you take off from something like a ridge among hills and throughout the flight. I've taken off from a peak, tried to fly over a hill probably 70 feet taller, and not been able to elevate over it when I got close because I got max altitude warning.
 
the manual that shipped with the Phantom was very brief, and the tutorials seem extremely basic. Is there better documentation available
Here's your manual:
https://dl.djicdn.com/downloads/pha...l/Phantom+4+Pro+Pro+Plus+User+Manual+v1.2.pdf
How accurate is the barometer for measuring height? If within wireless signal, does the aircraft take topography into account to report AGL height? Or is it simply a blind difference in assumed height between the aircraft and the starting position?
It seems like barometric pressure is a wildly inaccurate way to measure small changes in height, especially where there is changing air velocity and prop wash.
The barometer is more accurate than you imagine and works very well on the Phantom.
The Phantom has no way of knowing what is below it and all heights are relative to home point.

My current settings are to initiate RTH on connection loss, but that's not really what happened here. Will this retracing of the flight path always occur? Are there settings I can choose to encourage this behavior?
When I did select RTH, the aircraft didn't drop to my specified RTH height. Does the aircraft only use the specified height if a climb is required to attain that height?
Retracing to reconnect is an advanced RTH feature that is very smart programming.
RTH is probably the most important section of the manual - it has 3 pages on the topic.
 
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