Originally Posted by
cyccommute
Your average is 1274 feet ± 174 feet. From what I can see, the accuracy of phone elevation gain is ±30 m (98 feet). Your variance is a bit higher than that but not significantly more. I suspect your phone is using a barometer which would cause more error.
If that's the case, I wonder if the accuracy would vary on different days as the barometric pressure varies. I also wonder if any apps or devices use topographical maps along with GPS data -- I expect that would be significantly more accurate.