[Galaxy S I9000 General] sjdean:
Good question. I don't know.

Do you have the answer?

Maybe I should ask why do I and many others get bad tracks, if everything is right?

Maybe it is a bad batch of GPS chips, or a bad batch of phones. Perhaps you could be using it differently, mounting it in the car a different way, travelling at a slow speed, a high speed, maybe you don't make too many 90 degree turns, maybe you have clouds or no clouds, maybe you don't have any trees along your path, maybe you only make journeys when there is a lot of satellites in view and you've just been lucky, maybe it is a flakey GPS driver.

You told us talking about the GPS isn't going to improve things - not for you maybe, but I have problems, as do a lot of other people.

What's the problem, what's the solution, and what's your proof to back it up?

Come on, you told us off here for not being experts at GPS and Tracking and not having all the answers before giving us an answer of your own. Guess you must be an expert yourself, not just at GPS but at software and hardware design.

If it is software, then the issue should be reproducable, right? Under a specific set of circumstances? What are the circumstances?

That's all I've been trying to do through these threads. Make observations about how the GPS works.

Remember:

XXJF3 - Erratic but gives a raw GPS signal to things like MyTracks. With a Good GPS signal lock, this seems to be the best of all. It doesn't make things up. It can bounce between CellTowers and GPS and show lots of zig zag lines. The problem is GPS reception.

XXJG5 - We don't see too many zig zag lines, but we will see the system lose GPS lock and put you 100, 200m away convinced that's your new position based off cell tower triangulation, then it will attempt to draw a path between your last known good and where it thinks you should be, even if you get GPS signal lock back.

XXJM2 - Better Idea, in the event of a signal loss, it will take your last known good position and take into account sensor readings for heading and speed and plot a path. This could still be a lie though and I've seen lots of sweeping curves, cut corners and run on instead of turning left/right.

XXJM5 - Best of the bunch IMHO, but still suffers with the problem of losing signal strength.

XXJP3 - FroYo version, this sensor aiding data is quite clearly seen in a "Location and Security" menu.

Im noticing in XXJM5 and the Captivate GPS fix (perhaps relates to all firmwares) in GPS Test, it is preferring to use satellites in the middle two circles, even if there is a stronger strength satellite further afield.

All default firmwares appear to lock only onto Satellites > 20 SnR and upto 8.

NMEA data strings shows the internal GPS can lock onto more than 8 satellites and satellites with an SnR < 20.

A comparison of NMEA data and MyTracks recorded information can show very similar if not the same tracks, with the same loops at sections, so the bad maps aren't a result of MyTracks, but the underlying location reporting from the chip itself.

The captivate gps fix seems to resolve the > 20 SnR and 8 satellite fix limit, but I do not think that this actually fixes anything to do with accuracy.

The last two observations are the two main reasons Im concerned that this is a hardware issue, combined with the use of language that any updates will be "optimisations", and the fact that similar chips in the iPhone 4 and iPhone 3GS

Here's those sites again from more GPS experts, see if these tracks look anything like we've seen on the Galaxy:

http://www.gpspassion.com/fr/news.asp?id=752

http://www.gpspassion.com/forumsen/topic.asp?topic_id=135768

And here's some quotes:

No, I don't have the answers, but I have a lot of observations.