GPS Drift

This happens due to errors in calculating your position, when the unit is stationary, over time it's estimated positon will move North, South East or West of where it was by say a few feet, this movement will be logged exactly the same as if you really had moved a few feet because the unit has no way of knowing if it is real movement or error. As time goes on more and more of these movements will be logged due to errors

In car satnavs there are ways to get around these errors because the car moves much quicker it is possible to ignore any attempt to log small - slow 'jumps' as the car is not likely to be genuinely travelling at say 2 miles per hour, however it is not possible to use this technique when you are walking with your GPS because real movement and error movement look identicle.

This effect can be reduced by making the errors as small as possible, by having a clear view of the sky (uninterrupted by trees etc.), a more sensitive GPS or a GPS that tracks more satellites, these all reduce errors and that in turn makes for less 'false' movement

 

Yes the 'Auto Pause' option is basically the option I was referring to above for car satnavs, it's good to see Garmin have added this feature on some of the newer walking / hiking units