On Mon, Jul 15, 2013 at 4:34 PM, Claudius <gpsbabel.list@wolki.de> wrote:

Android Devices (Output from "GPS Status" App):
- 165m (MSL)
- 140m (MSL)
- 159m (Höhe +47m) "höhe" is german for height, Probably MSL/Goid
- 147m (MSL)

All of them claim a decent signal quality and have a fix to at least 9
Satellites. I guess the differences of ~27m is due to a lack of

Assuming the "right" answer is in the middle there somewhere, that's not really surprising; that's about the limit of accuracy on GPS altitude of consumer grade devices.  There's a reason why the FAA won't let you land a plane with that. 

Mehaffey and Allory wrote a good discussion of this (admittedly long ago) at http://gpsinformation.net/main/altitude.htm - one of the earliest really good sources of GPS info on the web, IMO.