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plotaroute admin Tuesday 08 Aug 2023 07:26:00
I thought I had provided an explaination below! It won't be down to where the route is, its more to do with the characteristics of the route. A relatively small amount of filtering or smoothing on a route that has lots of small changes in elevation will result in a big difference in the total ascent calculation between a system that applies filtering and one that doesn't.
Take an example of a route with the following elevation readings:
100, 101, 100, 101, 100, 102, 101, 100, 101, 100, 101, 100, 101, 100, 101, 100, 101, 100, 101The total ascent is the sum of all the uphill sections so this comes to 10.
However, if you apply filtering to ignore any changes in elevation lower than 2, the total ascent is only 2 .
That's just an example of how one type of filtering can make an apparently big difference, but other differences can come from things like the sampling interval, error correction and measurement accuracy.
As I said below, it is best not to try to compare total ascent figures from different systems for this reason. What is more useful, is to look at the relative difference between the total ascent figures of routes on the same system.
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Robert H77 Monday 07 Aug 2023 22:08:42
yes, Mark, I meant Doesn't explain such a large difference. Thank you
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Mark Worthington Monday 07 Aug 2023 17:41:02
"it doesn't explain" ?
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Robert H77 Monday 07 Aug 2023 10:30:50
Dear Admin
I fully understand what you are saying, but in the case, it does explain such a difference. I am well used to the difference between raw and filtered height on all my routes. could it be something to do with the mapping of certain paved paths in Germany and Holland?
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plotaroute admin Saturday 05 Aug 2023 08:08:00
When it comes to total ascent, unfortunately there is no such thing as a “correct” figure, as it depends on what rules you apply when calculating it. The other application you’re comparing with almost certainly applies smoothing or filtering to the data (most apps and devices do) and on this particular route a small amount of filtering makes a large difference. That’s not always the case, it depends in the characteristics of the route. On Plotaroute we’ve taken that approach of providing a calculation based on the raw data, without any filtering, which will usually be higher than other applications, but we also provide a route profile tool that you can use to apply whatever level of filtering or smoothing you like, thereby reducing the total ascent accordingly. So, for example, if you filter out changes in elevation under 19 feet, the total ascent calculation for your route comes down to just 275 feet. This is the main reason why you can’t compare total ascent figures from different sources.
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Robert H77 Friday 04 Aug 2023 15:01:12
Thank you for replying to my question. I understand your point about comparing using the same app to have a consistent base for comparing relative ehights of routes. But in this case the variance incredible. I need to have an accurate idea of the height I am able to climb in one day, or alse to choose another route. There is too much of a differnce between 290 and 1765 ft to leave it to chance on the day. If I cannot rely on a app being at least 80% correct, I am not sure it is very helpful.
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Mark Worthington Thursday 03 Aug 2023 18:02:23
Oh yes, I agree with the ascent comparison principle. I have recently moved from Tracklogs to Plotaroute and a comparison of many, many rides showed general agreement in comparing routes within the apps. I was less concerned with the absolute values app vs app.
The main edit route page shows the "raw" ascent data. Could it be possible to see the filtered data?
Is teh filter value per route? There's no genral setting for this?
When in Edit mode, I click "Hills/Explore hills in more detail" to get to the Route Profile tool. How do I get back to where I was in Edit mode? -
plotaroute admin Thursday 03 Aug 2023 08:37:15
I'm afraid its not possible to compare ascent calculations from different sources as they are all calculated differently. Please the the following FAQ for more on this: Why does the Total Ascent figure for my route differ from figures calculated by my GPS device or other applications?
On Plotaroute, the Raw figure is the ascent calculated wihtout any filtering and the Filtered figure ignores small changes in elevation lower than the Ascent Filter threshold in the Route Profile tool.
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Mark Worthington Thursday 03 Aug 2023 05:34:20
Maybe Admin could explain what this means ...
I uploaded it to OutdoorActive and it gives
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Mark Worthington Thursday 03 Aug 2023 05:23:51
Sorry, missed the (route number 2340493).
