I am getting angry ???????? with the constant craziness in Elevation Data. I run in flat park by the sea and it gets me several meters underwater and several meters flying!!! PLEASE GARMIN LET US DISABLE ABC ALTOGETHER
Have you calibrated the altitude sensor? since ltitude changes are measured via pressure changes, different weather conditions require re-calibration. Manually via Settings -> Sensors, or at the start of your activity. When you acquire a GPS lock, it's initially a 2D lock (i.e. without altitude). I remember reading Garmin documentation that if you wait another 30 seconds before you start recording, it should have acquired a 3D lock by then, i.e. including altitude. I usually do one or the other before every run and the altitude data is correct. Worst case, you can use altitude correction in Garmin Connect after the fact, but I haven't needed to so far.
I get the same thing on a flat 400m running track. Sometimes I get a decent elevation profile, sometimes it can be like a sawtooth, but most of the time the start elevation will be a lot different from the end elevation even though I start and end at the same location. I don't think it's got anything to do with the calibration - I normally wait 30 seconds anyway.
I find with my Garmin, with my Hammerhead Karoo, and and with my Pioneer head unit, with all of them, the profile is much better (not just with the absolute measurement, but also the amount of up and down) if I remember to calibrate right at the start of the activity. If I don't, the data is useless. For those of you saying that you don't think it has anything to do with calibration, have you at least tried calibrating at the start of an activity? Or is it just an assumption?
I've been having similar issues recently (I never paid attention before), all my runs usually start and finish at the same spot and the elevation between the 2 can be quite different. I've done a few runs along the coast and it has had me go below sea level.
I've tried running as soon as I get a GPS lock and also waiting 30+ seconds before running, it doesn't seem to make a difference. This mornings out and back is showing as more or less a constant down hill even after the turnaround when in reality if I had just run down, i'd now be going up, with me starting at 45m and finishing at 20m even though both points were my front door.
I've never really paid too much attention to this but as my next race is very hilly I've been trying to make sure I am running enough hills and been interested in the elevation changes, but the watch just seems unreliable.
Do we have a way to manually set the altitude at the start? Although this wouldn't fix the fact it seems to think I start and finish at different elevations when I don't!
I meant when if works correctly and it does > 90 % when I start from home from the same starting point. So didn't meant it always work correctly as it doesn't.
Calibration works fine... for the first 10 meters... Then I swim underwater... then I fly over the trees... As I run in a perfectly level surface by the sea...
What I have noticed is that pausing an activity tends to throw the altimeter off. Take the example from last night's run, a 10 mile out and back on a flat cycle path. I calibrated at the stat and it's all good, but when I got to the turn around point and paused the activity for less than a minute, I am suddenly 7m lower than I was before.
