Oh, just to update, on mine it is happening at 40-70'. However, the speculation on the air pressure/temp gradients may not be too far off. I've noticed it most when flying at home, where I'm taking off from about an acre of clearing of a hillside surrounded by trees, and I'm typically on the leeward side of the hill so I can have pretty different winds at ground level. My standard protocol is to launch a cpl feet, everything is stable then immediately get up above the treeline. This is where I've noticed it, after that launch up, then watching the altimeter stay the same while I watch the bird drift down and see the trees rise up on the screen.
I’m glad it sounds logical to you guys too. Knowing the altitude is only set by a barometer, when you say the altitude reading doesn’t change but it drifts up and down, I’m only seeing changes in air pressure or density as the cause. Birds ride updrafts, so it’s no secret air moves a lot,we just can’t see it. I’d be very interested to see someone test it in an enclosed warehouse at different elevations, using VPS and without it. I bet it’s pretty stable.
My bet (only a guess) is that that they adjusted the algorithm for altitude sensitivity to be more sensitive, with more of a curve smoothing factor or more time to average the change before making an adjustment. If that’s true, we should make a lot of noise to DJI so they readjust it for the better for the next update.
FWIW I’m new to drones but have a mechanical engineering degree. Controls always interested me! I have two flights on my P4P but I’m haunting these forums to know what to expect to avoid crashes and issues.
Is DJI good about responding to issues like this?