Gps fails in flight

[GoogleCodeExporter]

What steps will reproduce the problem?
1.arrange to fly in a high speed airplane 
2.While flying high and / or fast , attempt to use MyTracks 
3.Notice inability to receive GPS updates

What is the expected output? What do you see instead?
I see no reason for GPS updates to fail at high speed or elevation

What version of MyTracks are you using? On what version of Android? On what
phone?
Latest release as of 25-10-2011

If possible please provide a log.  Either upload here or send to mytracks-
support@google.com.
Detailed instructions can be found here:
http://code.google.com/p/mytracks/wiki/HowToReportErrors

Please provide any additional information here:

Original issue reported on code.google.com by Smith.Ja...@gmail.com on 25 Oct 2011 at 9:44

[GoogleCodeExporter]

Hi,

Please can you provide with the additional information such as 
phone/gps hardware,
mytracks version,
android version

to investigate the issue further.

Thanks,

Original comment by nage...@google.com on 9 Dec 2011 at 11:20

[GoogleCodeExporter]

It is illegal or at best ill advised to operate a phone while riding in a 
commercial aircraft.  Further the aluminum skin of the aircraft is likely to 
shield the receiver from seeing a sufficient set of gps satellites.   

On a commercial flight the phone should be in "aircraft mode" which will 
disable the radios.   

If mytracks was operating correctly and then went blind as you walked inside 
the aircraft my bet is that the skin of the aircraft is shielding the GPS 
antenna.

Be safe and take advantage of aircraft mode.

Original comment by nifty.mi...@gmail.com on 10 Dec 2011 at 12:49

[GoogleCodeExporter]

phone/gps hardware,
Samsung Google Nexus S

mytracks version,
MyTracks version 1.1.11

android version
Android 2.3.6  Build GRK39F

Original comment by Smith.Ja...@gmail.com on 13 Dec 2011 at 9:49

[GoogleCodeExporter]

Model GT-i9020T

Original comment by Smith.Ja...@gmail.com on 13 Dec 2011 at 9:52

[GoogleCodeExporter]

It isn't illegal to use GPS in an aircraft because it is a radio receiver not a 
transmitter. I've tried GPS on commercial flights with partial success. First 
you need to set the minimum sample distance big so that My Tracks doesn't get 
overwhelmed with data points. Getting a GPS signal is tricky. Some handsets 
have better GPS antennas than others. I have got a signal from the centre of 
the plane  but its rare. It works best if held against the glass window, even 
on your lap or in the seat pocket it will usually not be good enough. Your arm 
will not be able to do that for long though in the confines of cattle class. I 
stick the phone to the window with double sided tape. Some people will report 
you to the air crew if you do this but the air crew have always said its OK 
when that's happened to me. The problem really comes when your GPS loses lock. 
For a GPS to lock it has to know approximately where it is or it takes a long 
time to acquire satellite lock and on an aircraft the position has changed too 
much from when it was last locked and it is changing too fast to acquire lock 
the slow way. It can take a long time to get a lock even when, with the GPS 
test app, you can see lots of satellites.  It usually will in the end but if 
you lose lock it happens all over again. What is much more interesting than My 
Tracks is Google Maps because now that it has caching you can figure which 
river or road it is that you are seeing out the window.

Original comment by kenep...@gmail.com on 19 Dec 2011 at 12:06

[GoogleCodeExporter]

Sorry, we are not able to fix this.

Original comment by jshih@google.com on 23 Feb 2012 at 4:52

• Changed state: WontFix

[GoogleCodeExporter]

This discussion is misplaced, but in spite of intense searching I could find no 
other discussion about this particular problem. Therefore I will add another 
comment here now in the hope that we can continue this discussion for a little 
longer, even though it has nothing to do with My Tracks. We could also move the 
discussion to another venue if this is desired, like into the Android forum on 
http//winhlp.com/ or into one of the other Android forums.

I believe the problem has nothing to do with My Tracks, as it occurs with all 
other GPS programs just the same. Here are my observations.

I used to track airline flights with my old Garmin GPS receiver. The device was 
not very sensitive, but tracked most of the flight segments when being held 
directly to the window of an airliner, requiring a minimum of 4 satellites for 
3D tracking.

I tried the same with a HTC Google Nexus One. It did not work initially, but 
since upgrading its radio firmware to the latest available release and the 
operating system to CyanogenMod 7.2, it has worked exceedingly well and has 
been a very reliable track recorder in flight.

Then I bought a Google Samsung Galaxy Nexus. While being a very nice phone 
(apart from its obvious shortcomings like very limited and not expandable 
memory) it has failed to record GPS tracks in flight. It does record very 
nicely and reliably during takeoff and landing, but after takeoff and some 
climb it fails in a peculiar mode. A typical example is that the GPS Status app 
shows some 8 satellites, all green, i.e. perfect reception, but the position 
and speed indicators are frozen to some obsolete value. Other programs that 
show the GPS track on a map, like Locus, also freeze the aeroplane indicator 
and end track recording.

I feel stupid now, because I had heard multiple times that Samsung phones 
contain crappy GPS receivers. I would be interested in hearing reports on other 
phones, particularly new HTC and Motorola phones.

It seems that the Galaxy Nexus and possibly all other Samsung phones have an 
arbitrary limitation programmed into them that stops GPS position updating when 
the plane is either faster or higher than that limit. I could not find out so 
far whether it is the speed or the altitude that causes the failure. Obviously 
this is not a normal technical limitation, as other older and cheaper phones 
and other cheap consumer GPS receivers show no such problem.

I would particularly like to hear about workarounds, patches, alternative radio 
firmware, etc., that could repair or work around the defect in the Samsung 
Galaxy Nexus.

Attached is a screenshot of GPS Status in a typical situation with excellent 
reception of 9 satellites. The position and speed figures were no longer 
changing after a certain point.

Original comment by hgm...@gmail.com on 21 Sep 2012 at 9:11

Attachments:

• Screenshot_2012-09-17-14-43-10[1].png

[GoogleCodeExporter]

Added new topic "Samsung Android phone GPS defect" at 
http://winhlp.com/node/889 . Please continue this discussion there if you feel 
that it does not belong here. The web site requires a simple registration for 
posting.

Original comment by hgm...@gmail.com on 21 Sep 2012 at 9:35

[GoogleCodeExporter]

Despite this post being almost 2 years old, I would like to add my little 
contributions (and great frustration).

I have a Samsung Galaxy Nexus (currently running CM11, although it was on stock 
when I first noticed the problem) and I run into the same issue. Furthermore, I 
was able to verify that the problem is the altitude: above 4000 m the gps 
reports no fix, despite having plenty of satellites in view. I experienced this 
during several hikes, when the latest recorded point before the fix loss would 
be just a few meters below 4000 m (and I assure you I wasn't going nearly as 
fast as an airliner! :)).
See also this post on XDA:
http://forum.xda-developers.com/galaxy-nexus/help/galaxy-nuxus-gps-issue-4000-m-
13000-ft-t2622906

Unfortunately, since the OP reports using a Nexus 5, I suspect this is a (very 
bad) limitation of the Nexus line... very frustrating.

Giacomo

Original comment by jackseri...@gmail.com on 7 Aug 2014 at 4:24

[GoogleCodeExporter]

I can report now, after several years of frustrated GPS use on a Samsung Nexus 
S, that the device and or software controlling it are simply crap.

I have done extensive research on this subject now, in fact I am probably one 
of the most well versed people in GPS technology in the world as a direct 
result of my frustration with this issue.

The fact is, there is no reason for this to be happening other than poorly 
spec'd hardware or really poor quality software.

Having tested other Slater nexus models since my first report, I can report 
that the issue is simply as stated.  A good hand-held GPS, yes, costing 
considerably more - has no problem with accurately logging a 
transcontinental/transoceanic flight.  The reason the other device costs more 
is nothing to do with hardware per se, and everything to do with low sales 
volume.  Considering the multi-million sales record of Nexus devices, there is 
zero excuse for this.

Original comment by Smith.Ja...@gmail.com on 7 Aug 2014 at 4:33

[GoogleCodeExporter]

I understand and share you frustration, although i have to admit that the high 
altitude problem is the only one (but bad enough!) I have experienced with my 
Samsung Galaxy Nexus.

Also, I realized that I misread you previous post: you are using a Nexus S and 
not a Nexus 5. So, the question remains if the Nexus 5 has a problem above 4000 
m or not...

Original comment by jackwor...@gmail.com on 7 Aug 2014 at 4:38

[GoogleCodeExporter]

if (altitude >= 4000) return null;

Is this a programming error or is it sabotage? Oh well! It can conceivably kill 
someone, particularly since nobody in his right mind would suspect something 
like this after always navigating perfectly fine below 4,000 m.

If anybody is reading this and knows whether other popular phones do or don't 
have such GPS defects, please report.

Original comment by hgm...@gmail.com on 7 Aug 2014 at 4:53