I ride a mountain bike, a lot. I've been curious about the large scatter in ascent/descent data reported for a given trail by various users. I ride with a Garmin Edge 130 plus, which has a barometric sensor to generate elevation data. I've also been turning on my iPhone and running Gaia, Strava, and Trailforks simultaneously. These three are all taking GPS positional and elevation data from the iPhones GPS chip, right? What I find is that the ascent/descent information from these three GPS apps yield large scatter in the reported ascent/descent data by as much as 40%! -- if the data source is identical, what are these three apps doing differently? The distances reported by the three apps on a given ride are reasonably close.
Gaia routinely reports the lowest values ascent/descent.
I've also been riding with my Suunto altimeter watch. The Suunto (barometric) and the Garmin Edge (barometric) are generally within a few percent of one another. The three GPS programs report higher and lower than the data from the barometric sensors, by +- 10-15%.
It would be nice to understand these disparities, especially among the three GPS-based apps.
Please sign in to leave a comment.