[OSM-newbies] comparison between gpx results

[Francis Augusto Medeiros]

On 3 de abr de 2007, at 02:03, Georg Wassen wrote:

> Hi,
>
>> It seems that the numbers on GPS Track were much more realistic than
>> those from Mobile Trail:
>
>> <trkpt lat="-14.85533120185395789" lon="-40.82430315644915563"></ 
>> trkpt>
>
>> <trkpt lat="-14.848281666666667" lon="-40.837698333333336">
>
>> While GPS Track has very different numbers after the dots, Mobile
>> Track repeats a lot, looking like it interpolates stuff.
>
> This looks like a single/double precision issue to me. While the above
> uses double presision calculation, the numbers below are rounded to
> single precision.
> In your region, a difference of 0.001° is 1.79m in latitude and  
> 1.85m in
> longitude. That's already the GPS precision, you can cut the remaining
> places ;-)
>
> In my opinion, you shouldn't worry about the precision after the sixth
> decimal place (representing millimeters).


Hello Georg,

Thanks for your answer.

When I load both tracks on JOSM, the difference between the tracks  
are too big. so I feel a bit concerned about the results. So I am  
concerned which one I should use.

Cheers,

Francis