Unfortunately, determining this data correctly is harder than it may seem at first glance. One of the reasons is, that the GPS-signals are not always very accurate. The GPS designers decided to lay their focus on horizontal acuity (and rightfully so). Due to this focus, the vertical data determined via GPS is not as accurate in comparison. What does that mean? It means that, even if you are traveling on a seemingly plane surface, it is possible for "virtual inclines" to occur - simply because the altitude is recorded too high at one point, and too low at the next.
Plus, the GPS sometimes determines entirely incorrect values and jumps a few hundred meters, as shown in the illustration below.
On the other other hand, the fans of different types of outdoor sports have different expectations when it comes to the "correct" altitude data. In case of mountaineers, it's above all the distance between the valley and the summit that counts. For bikers, even smaller inclines during a Tour may be of high importance.
So we can give you values that are as close to reality as possible, komoot analyses and processes your GPS-data by means of especially developed algorithms. During this process, we remove the above-mentioned virtual inclines. The same happens in case of significant jumps in the GPS-signal. In addition to this, we have tried to find a method of calculating that covers as many different types of sports as possible and thus offers plausible values for most of our users.
Despite of this, deviances to the values you may expect when recording a Tour can still occur. That may happen, when outliers are too high and occur too often, as well as in case of general inaccuracies, which may occur for instance in case of especially cloudy skies. When starting to record a Tour, the GPS signal also tends to be quite inaccurate still. If you wait at least half a minute before starting your Tour, you can avoid this particular problem.
You can help us improve our algorithms even further. Just send us examples of your recorded Tour using the following form.