Wrong elevation gain during recording

Mike shared this problem 3 years ago
Solved

Hello


locus is recording a track

the altitude is measured by the integrated barometer


during the recording the shown altitude in the sidepanel and the dashbord is correct.

but the shown elevation gain in the sidepanel and dashbord is wrong. it shows too much elevation gain.


when the recording is finished and you look in the overview of the recorded track you can see the right elevation gain.

there is no automatic data correction activated.


Also see: http://forum.locusmap.eu/index.php?topic=4520.0

Comments (21)

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Hello Mike,


agree that this is little bit confusing. Problem here is, that what you see during track recording ARE REAL values measured by your device. They are usually quite noisy, so when Locus save after end of recording your track, there is a mechanism that optimize these values to some more logical results. So after save of track, you see already optimized values.


Doing this optimization also during track recording is currently quite complicated and I CPU & battery consuming, so I decided to do it after track is saved, just once.


Anyway as I wrote, I agree that this is not a perfect solution because it is little bit confusing if you do not know it.

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when I use the audio Trainer i also get the wrong (old) elevation gain.

can it changed that it tells me the correct Revelation gain from the Dashboard/sidepanel ?

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Good day Mike,

simple change is currently not possible. I really hope to find enough time during start of next year and look on this problem more completely and unite it for whole application. It's a plan, thanks for understanding.

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OK, i already thougt that this a problem between condensed and real data.


but i also checked the altitude thats shown in the sidepanel.

it looks quite reliable, it shows the correct data all the time.

so is it possible to change the elevation gain from real data to counter of the altitude thats shown in the panel?


i mean: shown altitude +1 --> shown elevation gain +1

i am well aware that the result would not be perfect, but better than the current which is completely unrealistic.


the result in the overview is perfect, so this should be retained

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Hi Menion,


as already mentioned above there is a sever difference between the recorded meters in altitude during track recording and the data you see when the track is saved.


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Data during track recording


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Saved track data


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Data in the statistics file.


1) As you said the data shown during track recording are real values measured by the device used. If you use a barometric supported device and you have set Locus to barometric the values shown are the barometric ones.


2) If you use a non barometric device and the correct setting the values shown should then be the GPS data.


3) What does Locus do when you save the track record referring to point 1 and point 2? What values are shown when saved.


4) The data shown in the statistics file always stay untouched independently if track saved or not. What kind of values are used there?


Barometric obtained meters in altitude are pretty well in accuracy whereas GPS data in altitude blow. But this is not your business Menion, you have done your job darn well.


This all is a bit confusing and a few nice explaining words in the program which pop up with respect to the program points your gonna use would be a fine idea and avoid stumpling.


Have a nice day


Regards Rudi

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Hello Rudi,


1, 2) Barometric data are automatically merged with measured and computed values so in the end, there is nothing like "barometric" only altitude.


3) when track is saved, measured values are always stored, not some optimized. So when you then export recorded track to GPX, you always get file with real measured values. Useful info for some self-check or test on any analyzing web site. After data are saved, Locus compute new optimized values, that are shown in chart.


4) ah you are correct - values in laps are not filtered so they show real measured (unrealistic) altitude values


--------


Anyway, I see here clear problem that should be improved and visible values should be united. So I absolutely agree, there should be no (at least not big) difference between values from current track recording and values visible on already stored track.


I'm writing this as a task on June and I'll try to improve it. If during June, there will be no change, kick me little bit ;). Thanks

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Tried the new version today


works perfect.

thank you

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Perfect, really glad to hear it. Keep it mind that there will still be a small difference, but should be a lot lower then before.


Thanks for useful bug-report!

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No change for me. Stats on a short hike yesterday had 1000 feet more gain (on the dashboard) than the saved track. Should I change a setting somewhere?

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Nope. Were you using latest 3.9.3 version?

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Yes, using version 3.9.3.

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hmm around 300 meters is not so bad, depend on profile and length of your track. Anyway for now, I have no better solution.


Only what may influence it, is increase altitude filter in altitude manager: http://docs.locusmap.eu/doku.php?id=manual:user_guide:tools:altitude#elevation_data , which should optimize received altitudes a lot.

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Thanks, I'll try boosting up the filter to high from medium and see what kind of difference it makes.

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on dashboard it shows 653m

after saving it was 603


all values generated by the barometer


blulynx, do you use the gps values?

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Yes, I do use gps values. My settings settings under Altitude Manager are "Altitude NMEA correction" I keep trying to reset it to "Automatic correction" but when I check again it's back to the NMEA correction. Not sure why, but maybe this is the problem.

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Just downloaded some information that is now allowing me to use the Automatic setting. Will check on next hike (not for a few days yet) to see if that fixed the problem.

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Have tried different settings now on a couple of hikes. The Automatic setting improved the dashboard elevation gain stat by 50%, but still not accurate enough to be able to stop saving "actual part" of a track so I can later collect elevation gain to that location. Tried boosting the filter from medium to high but saw no change.


Maybe Automatic is not the best setting either. What setting do you use Mike? How are all of your values being generated by the barometer?

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yourproblem is the gps.

without a phne with barometer you will never get "correct" values

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My phone is suppose to have a barometer (Samsung Galaxy S5). Don't know how good it is though.

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this sounds good.


Thank you.

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Many thanks Menion, you're the very best. I think about you in July when I'm driving the Kammweg in Krušných hor.


Have a nice day


Rudi