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RE: Mountain biking Los Gatos California, BTC calm before the storm?
If i am not mistaken, the Garmin Vivoactive does not have a barometer. So the elevation gain would be way off target. It would be reading almost double of the actual climbing
The Garmin Vivoactive has GPS which typically has 3 satellites tracking the device. The elevation gain is fairly accurate, it is off by a few feet when two people ride the exact same ride and compare elevation gains.
Ah, yes. But elevation gain calculated from a GPS is not very accurate.
You can compare your data with someone using a Garmin Edge 510 or above. The watches do not have a barometer afaik.
From https://support.strava.com/hc/en-us/articles/216919447-Elevation-for-Your-Activity
Also, you can go through many similar threads on the Garmin forums:
https://forums.garmin.com/forum/on-the-trail/wrist-worn/fenix-3/102206-true-elevation
This is from Garmin regarding GPS and elevation gain:
GPS heights are based on an ellipsoid (a mathematical representation of the earth's shape), while USGS map elevations are based on a vertical datum tied to the geoid (or what is commonly called mean sea level). Basically, these are two different systems, although they have a relationship that has been modeled.
The main source of error has to do with the arrangement of the satellite configurations during fix determinations. The earth blocks out satellites needed to get a good quality vertical measurement. Once the vertical datum is taken into account, the accuracy permitted by geometry considerations remains less than that of horizontal positions. It is not uncommon for satellite heights to be off from map elevations by +/- 400 ft. Use these values with caution when navigating.
It is much harder and time consuming for someone to calculate based on a topographical map, which is why most people use GPS these days.
On another note, double the elevation? If you followed me up this route, you would know that it was not 1000 feet of climbing.
Thanks. That was informative :)
Haha. I wouldn't mind following you up that route. It looks like a real nice place to ride a bike.
Double the elevation comment was made with regard to my personal experience. Where our comps would show 1400-1500 metres. The watches and smartphones would be showing anywhere between 2600-3000 metres of elevation gain. Which as you would agree is considerably off!