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en:help:v2:landmarks:statistics [2016/04/28 11:53] – alpinequest | en:help:v2:landmarks:statistics [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1 | ||
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- | ====== Statistics ====== | ||
- | Display the details of a track to get its complete details page, made of | ||
- | * A preview section {{: | ||
- | * A complete statistics section {{: | ||
- | * A list of events occurring during the track {{: | ||
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- | The statistics section is divided in sub-sections: | ||
- | * The overall statistics {{: | ||
- | * Statistics on elevations {{: | ||
- | * Statistics on moving speeds {{: | ||
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- | Click on ''" | ||
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- | {{ : | ||
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- | ===== Gain and loss ===== | ||
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- | The gain is an important value that helps to appreciate the overall profile of a track. A small gain means that the track is mostly flat, a high gain means you'll have to climb a lot. | ||
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- | Strictly speaking, | ||
- | * The **gain** is the sum of all **positive** altitude differences along the track; | ||
- | * The **loss** is the sum of all **negative** altitude differences along the track. | ||
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- | In order to compute these values, it's important to define more precisely what means "along the track" | ||
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- | A first definition would be to only take into account **the altitude differences between mountain passes and summits**. If you start a hike at +150m, climb to a summit at +500m, then go back to your start location at +150m, your gain will be 350m. In practice, trails usually don't go straight forward to the summit, but will go uphill for some time, then downhill a little bit, then uphill again, etc. This first definition doesn' | ||
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- | Another definition would then be to take into account **the altitude differences between all the locations that make the track**. Now imagine a track recorded with a GPS along the sea. The GPS, having an imperfect accuracy, will record altitudes of [+1m, +2m, 0m, +1m, -1m, +2m, ...]. With this small segment of 6 locations, we have a gain of +5m. With a track of 1000 locations, it would lead to a gain of more than +800m which is a very **over-estimated gain**, since the track is along a flat shoreline and should have no gain. | ||
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- | At then end, the " | ||
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- | Here is the effect of the noise reduction on a track profile and gain computation: | ||
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- | * On the left, the noise reduction is disabled. The profile displays the unmodified jagged and spiky altitudes {{: | ||
- | * In the middle, the noise reduction is on ''" | ||
- | * On the right, the noise reduction is on ''" | ||
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