Peter Collins wrote (see)
Sorry, what am I looking for...?
I'm guessing we are looking at the frequency of data points along the route showing that the Garmin is recording about 58 data points compared to about 14 on Runkeeper on the iPhone and 12 on Runkeeper on the HTC.
I also guess the logical conclusion is that the more data points along the route the more accurate the plotting of the route and consequently the more accurate the measure of distance travelled.
Does that sound right or am I missing something and that logic is flawed ? It is interesting to see it so clearly represented on these images but not too surprising.
As a matter of interest what distance did each device record for the total run ?
I use a Garmin 405, and it seems to be very accurate against measured race distances. As Cougie says, that's what it's designed for.
I just like to know how far I've run on training runs, and I use it for speed sessions as it beeps to tell me when I have to speed up/can slow down
You can probably get an app for that, but then I don't have an iPhone
Yes, I've found the same, I now run only with the Garmin and then upload the data onto runkeeper.
It's up to the application to request current GPS position from the iPhone but the more requests you make the lower the battery life. When Runkeeper first launched the battery life was less than a couple of hours with it running so I imagine they've got some smart filtering that varies requests by current speed to get a trade off of accuracy vs battery life.
The Garmin GPS algorithm is tried and tested. I've used one of their Etrex units for years. It works out how fast you are moving and how often you change velocity and plots the points appropriately. ie if you speed up and slow down it is picking up your speed changes and if you are weaving side to side it is picking up your direction changes. If you run in a straight line quickly the points will be more spread out.
All GarminGPS does is plot points (and some heart rate stuff?).
The iPhone and the HTC are limited on memory and battery life and also have to do lots of other functions. I suspect that they limit the number of points appropriately.
seren nos wrote (see)
but the garmins are never 100% accurate .so you have to use common sense...................for a couple of races i have worn one on each arm and they do get out of sync.sometimes significantly.......at 1 20 miler recently my left arm ran .2 of a mile further than my right arm
Seren is quite right - my Squeeze and I run together sometimes, and his Garmin 305 would consistently record a longer distance than mine, and also on race distances (where mine is usually within 0.02 of a mile to the race distance).
He's just bought a new one (can't remember which number), so it'll be interesting to see if that is more accurate.
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