altitude calibration for OsmAnd on Android phone ?

[Vincent Carlson]

Hi,

On my Samsung Galaxy A3 (2017) (Android 8.0.0, OsmAnd 3.0.4), I noticed that the reported altitude on the dashboard is consistently off by 30~60 meter.

An obvious case is when I was on the sea lately; the 'GPS Status' Android app correctly reported an average alt of 1~2 m, while OsmAnd insisted on saying that I was at about 50 m.

There is always this difference of 30~60 m between GPS Status and OsmAnd (and the former is always closer to the reality).

Obviously they both rely on the same GPS data....is there a way to compensate the altitude offset in OsmAnd ?

[Poutnik the Wanderer]

Some applications have available automatic correction of WGS84 geoid
altitude ( Earth geometric model GPS uses ) on the true sea level.

E.g, uncorrected GPS altitude in Central Europe is about 60m higher than
the true topographic altitude.

Some other applications offer just user defined numerical offset.


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Dne 14. července 2018 14:21:12 Vincent Carlson <venbc...@gmail.com> napsal:

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[Vincent Carlson]

Thank you

If I understand correctly, this means that OsmAnd displays"raw" GPS altitude information, while GPS Status might be performing automatic offset correction (and hence display what appears to be the real altitude) ?

Is there a setting in OsmAnd to manually set an alt correction ?

[Max1234Ita]

HI Vincent,
I don't think there is such an option in OsmAnd, most probably the app relies on the measured position and then it adjusts the altitude with the information provided by the "World altitude correction" module, which is available for download in the World maps section (Download maps menu).

Did you already download it? If not, give it a try ;)

Cheers,
Max - Italy

[Vincent Carlson]

Thank you Max

It's exactly what I needed - a shame I overlooked that !

Cheers

[Max1234Ita]

Glad you solved.

Have a nice trip! ^^

Max

[Tijmen Stam]

I had this same problem. Then when I moved to a new phone, I needed to DISable the world altitude corrections. And for my current phone, I needed to reenable them again.
So I guess some phones already do the corrections beforehand while others don't, and some software has a way of knowing whether the phone does this correction.

[Greg Troxel]

The Android API specification is quite clear that ellipsoidal height
must be provided. So some phones are doing it wrong. I wonder if
there is a list and that's how some code knows.