Originally Posted by
tenrec
I just found something else of interest: looking back at my records, I found a couple of rides in 2016 which I tracked using both Strava and the Samsung S Health apps. On the first ride, over a 23-mile course, Strava recorded the elevation gain as 1299 while Samsung pegged it at 1721. On the second ride of 17 miles, Strava recorded a gain of 892 feet, while simultaneously Samsung gave me 1381 feet. The phone I was using at the time was probably a Samsung Galaxy S8. So here are examples of different apps on the same phone at the same time giving wildly different reading of elevation gain.
Doesn't surprise me. GPS is an inherently noisy system, and there's a lot of signal processing software embedded in a good GPS system's chips. I suspect Samsung focuses on location (because that's what most people want, like do I turn left or right to pull into the doughnut shop?) and lets the elevation fall where it may. Strava will try to post-process the intermediate GPS track your phone produces to fit it onto its maps. As long as lots of people have ridden those roads and tracks, Strava will cut the noise in the phone track down. Does that mean Strava is "right?" Well, it means Strava likely has a better estimate of the climb.