Posts for this topic...
-
Post your comments.... Sign In to Post
-
plotaroute admin Thursday 09 Oct 2014 17:42:04
Hi Andrea - I'm happy to look into this if you can give me an example but I suspect the difference between our calculations and what you are comparing it to is down to sampling frequency.
The total ascent is calculated by adding up all the height gains at regular intervals along the route. Taking elevation samples at more frequent intervals will tend to result in a higher total ascent than taking them at less frequent intervals, but is arguably more accurate. We sample elevation readings every 10m, so our calculations should be very accurate. I'll give you an illustration:
Distance Elevation Total Ascent
(10m sampling)Total Ascent
(50m sampling)0m 10m 0 0 10m 12m 2m 20m 10m 2m 30m 10m 2m 40m 14m 6m 50m 11m 6m 1m 60m 10m 6m 70m 10m 6m 80m 8m 6m 90m 14m 12m 100m 12m 12m 2m This 100m route has a total ascent of 12m if you sample the elevation every 10m but only has a total ascent of 2m if you sample the elevation readings every 50m. For this reason, it is usually not possible to compare total ascent calculations from different sources due to differences in calculation methods.
-
Andrea Ticci Thursday 09 Oct 2014 13:52:29
Hello,
I realize that the calculation of the overall ascend is inaccurate and always overestimating (even by a factor of x 2) the real elevation gain.
Andrea
