I just bought a Garmin 935, and I'm noticing that when I upload runs to Strava the "elevation correction" is always different from the elevation data from the watch's barometric altimeter. Which of the two is most accurate?
I just bought a Garmin 935, and I'm noticing that when I upload runs to Strava the "elevation correction" is always different from the elevation data from the watch's barometric altimeter. Which of the two is most accurate?
http://xcmag.com/news/gps-versus-barometric-altitude-the-definitive-answer/SC Steve wrote:
I just bought a Garmin 935, and I'm noticing that when I upload runs to Strava the "elevation correction" is always different from the elevation data from the watch's barometric altimeter. Which of the two is most accurate?
A potential issue with barometric pressure altimeter is that it can vary depending on weather conditions. Low pressure fronts and high pressure fronts.
SC Steve wrote:
I just bought a Garmin 935, and I'm noticing that when I upload runs to Strava the "elevation correction" is always different from the elevation data from the watch's barometric altimeter. Which of the two is most accurate?
Strava. Maybe.
Strava accepting the values of barometric altimeters as accurate is why you have the leaderboard on climbing challenges full of bogus numbers. I typically use the number reported on Garmin Connect for my 225 (no altimeter) as the most accurate. I remember looking at the data for the person that finished behind me at a recent marathon who used a Suunto with an altimeter. It reported triple the elevation of my run, seemingly from reporting constant hills over the flat sections of the course.
The only glaring errors I've seen with my GPS numbers are when I run of a certain bridge and it seems to think I jumped off the cliff, skipped across the river and back up the cliff on the other side. Most other bridges don't have that issue.
Bump.
r2k83 wrote:
I remember looking at the data for the person that finished behind me at a recent marathon who used a Suunto with an altimeter. It reported triple the elevation of my run, seemingly from reporting constant hills over the flat sections of the course.
The only glaring errors I've seen with my GPS numbers are when I run of a certain bridge and it seems to think I jumped off the cliff, skipped across the river and back up the cliff on the other side. Most other bridges don't have that issue.
Both wind and temperature effect barometric readings.
Your second issue comes from GPS units not being sensitive enough to map your run exactly. The third link below has an excellent explanation of the issues of GPS runs going off cliffs and through solid rock and meandering off of bridges. (A Stryd footpod is what the user found as most accurate routing device.)
https://www.reference.com/science/temperature-affect-air-pressure-90b37da760fa9d12https://barani.biz/kb/wind-speed-barometric-pressure/http://fellrnr.com/wiki/StrydLuv2Run wrote:
http://xcmag.com/news/gps-versus-barometric-altitude-the-definitive-answer/SC Steve wrote:
I just bought a Garmin 935, and I'm noticing that when I upload runs to Strava the "elevation correction" is always different from the elevation data from the watch's barometric altimeter. Which of the two is most accurate?
A potential issue with barometric pressure altimeter is that it can vary depending on weather conditions. Low pressure fronts and high pressure fronts.
Most watches don't even have a temp sensor making the barometric altimeter dead in the water from the beginning.
Saywhat2 wrote:
Most watches don't even have a temp sensor making the barometric altimeter dead in the water from the beginning.
For a running watch you mostly only care about relative altitude, so unless there are rapid changes in barometric pressure they work pretty well, certainly a lot better than unaided GPS altitude unless you run through the eye of a hurricane or some such.
I haven't used Strava, but the online tools I've experience with seem to use digital terrain elevation data, that is, a digital topographic map assuming you're following the surface contour which is why they sometimes blow it when you run over a bridge.
Of possibke intetest - Strava has an FAQ page explaining the multiple ways they estimate elevation of your data:
https://support.strava.com/hc/en-us/articles/216919447-Elevation-for-Your-Activity
Alex FreeMarket wrote:
Of possibke intetest - Strava has an FAQ page explaining the multiple ways they estimate elevation of your data:
https://support.strava.com/hc/en-us/articles/216919447-Elevation-for-Your-Activity
Nice find, thanks for posting.
Neither is completely accurate. Or even close. GPS will tack your coordinates on a Aero LIDAR based coordinate system that is accurate to like the nearest 20 feet...so running in the trees you may vary elevations by 70 feet. The during run elevation is based on triangulation, which on a watch is accurate to like 50ft.
Barometric Pressure is complete nonsense in a watch. The calibrations required to have that be accurate are only built on equipment that is well over 100,000 dollars.
Both are more for fun and reference.
Neither.
Your watch isn't accurate. Strava makes no attempt at correcting for accuracy.
pop_pop!_v2.2.1 wrote:
Neither.
Your watch isn't accurate. Strava makes no attempt at correcting for accuracy.
Amen...
Strava can't even create an app with a lap button or custom workout wouldn't expect them to do anything in-depth regarding elevation or other advanced features.
Am I living in the twilight zone? The Boston Marathon weather was terrible!
Des Linden: "The entire sport" has changed since she first started running Boston.
Matt Choi was drinking beer halfway through the Boston Marathon
Ryan Eiler, 3rd American man at Boston, almost out of nowhere
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