Altitude - bad accuracy
Opened this issue · 2 comments
Hi,
I noticed on ~20 phones, that GPSLogger give higher altitude(elevation), than relly is.
So I made some test with GPS Logger logging on background and GPSStatus opened in foreground keeping GPS alvays on.
GPSStatus shows altitude 322m all the time (see screenshot at 13:33:05 and 13:33:10).
Meanwhile GPS Logger sent position with altitude 366m (see screenshot at 13:33:05 and 13:33:07).
What is source of this data for GPS Logger? There must be some bug...
(accuracy 8m and satellites 22 is the same for both applications)
I think what's happening here, is GPSStatus is showing your MSL Altitude, while GPSLogger is reading the altitude straight from the Location object provided by the OS, which uses WGS84 Altitude. That's the clue I'm getting from the "MSL" in the GPSStatus screenshots. Read the difference
Under performance settings, there is an MSL toggle, right near the bottom. This should take the altitude and subtract geoidheight, and that should match closer to what you see in GPSStatus. You can also add your own offset. But take note, if geoid is not present, then altitude will be ignored.
When "google location accuracy" is on osmand record garbage altitude data. Haven't checked if that's the case for gpslogger as well.