I use GPS to fly UAVs and I've seen errors in GPS altitude up to 50ft compared to barometric altitude. Generally it's better than that, though. It's accurate en

I use GPS to fly UAVs and I've seen errors in GPS altitude up to 50ft compared to barometric altitude. Generally it's better than that, though. It's accurate enough for us to fly autonomous helicopters with the barometric sensor disabled. I'd say that disproves the inaccurate and low-resolution claims ;-)