2 Identical Spartan Ultras Recording Same Activity w/ Different Mileage
On several occasions, we have recorded the same activity and after a few miles the watches start to have a discrepancy in mileage. Over a 20 mile hike for example, we have had more than a 1/2 mile of difference in total miles. We both have Spartan Ultras and use them on the GPS Best setting with glonass turned off. we don’t expect them to be exactly the same, but does anyone have any ideas of what we can try to get the distances more accurate?
you can not 100% compare if two different people wear the watch, not even within the same hike. It’s not even the same if you have one watch left and one watch on the right arm, if you want to have a very accurate comparison.
1/2 mile is a lot, but you can only judge if you wear both on one arm.
I imagine this: you might have a different walking style, you behave different during a short rest (and leave the watch in recording mode), maybe nature is calling and you two walk different distances for that business?!
All those YT videos of testing one wrist with one watch and other wrist other watch or all watches on same wrist are pointless as they are statistically insignificant. You can measure 10000 times and you may get variation on data that distort average value. For a real distance you need to measure it 10000 times and all get same result, or result that is lets say 3 sigma requires all measurements to be within 99.7% accurate.
GPS is not measurement it’s an estimation of your location so you don’t find yourself on a wrong path or down in a illusion of measuring distance rabbit hole. So is your sports watch, altitude reading, power meter and perception of reality.
Want to measure a distance use a calibrated measuring wheel.
@TELE-HO Understood and I’m not looking for a 100% comparison. Yesterday morning we recorded a 6 miles run in the city and had almost identical mileage. So maybe, we are losing gps signal during backwoods trekking. I do appreicate your reply!