Phantom not reading height correctly

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Hi all, any thoughts on the following. My 4 seems to be registering a height that is consistent about 5 feet too high. For instance when I am at 5 feet, it reads 10. When I go to land and get below 5 it seems not to want to go to the ground. It fights the down throttle a little, almost like it wants to take off, but then lands and I shut it down. Any thoughts?


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Mine is the same, especially when flying in heavily contoured areas. It is reading the height relative to its take off point and had me recalibrating the IMU etc until I realised this is normal. As for being reluctant to land, the sensors are doing their job in maintaining relative height to where it is, I hand catch mine to avoid going through that bit of anxiousness.
 
Correct altitude readings are not the Phantom's strongest point. They waver and we don't really know how DJI engineers have come up with the altitudes it reports. Barometer, bottom sonar, bottom camera VPS, GPS, software, and maybe firmware and how much they relate to each other in the program we don't know.

Mine is often off 50 feet, mostly to the negative side upon landing when take-off is fine at zero feet. Even just sitting and warming up the altitude might climb a bit in GO while still on the grass as well as the true distance from me. Put it in a level flight and fly a box pattern for 15 minutes and watch the altitude change in GO. Later play it back in the Flight Review and then you'll ponder why it drops and sometimes rises as much as it does. Seems almost like an interference signal making it waver. Dunno.

I know there are more accurate drones out there that claim an accuracy of 7 inches (e.g. Trimble Surveyor's drone.) but DJI isn't one of them. Maybe in time they'll figure it out. The Inspire 2 supposedly has two barometers and also more redundancy circuitry so maybe they are more accurate...maybe...but much more money too.

I don't have any issue in landing and greasing it in, but I use the sticks and do it manually. I don't use the auto-land feature as I don't trust how it might decide to land hard or bounce with the odd altitude numbers. If it decides the landing spot is now -45 feet (reported) it might come in a bit hot.
 

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