Minimize GPS-errors on Tracking

[franc]

...treshold will be reduced to some more real value - like you said 2500km/h...h

Oh, why not a more realistic and lower value, or, much better, a setting for max. allowed jump?
Or just a setting for this whole checking?
Then the few rockenauts can track their ride to mars

[menion]

I'm not big fan of new un-needed settings. I think this should be solved by any clever algorithm, that will remove such nonsences. I've added some more checking so we'll see. In case, that in some track will be again such problem (probably smaller but will be), send me it on email

[PeterPablo]

Menion, I think your argumentation is reasonable. And what you implented now, seems is what I suggested in this thread: "filter out some nonesense values like extreme jumps in lat / lon" ..between two succeeding points.

Your current approach was useless because due to bad gps-reception it took a rather long time until the next valid point came in. This then reduced the "virtual speed", as you already noticed.

We will see, wether your new approach is sufficient :-)

[PeterPablo]

Yesterday I created a log with "OSMTracker" and experienced the same issue. Sot it is not only you, who has problems with "jumping" of gps-positions.

[franc]

It happend twice to me, that I logged at the same time with MyTracks and Locus (I wanted to compare the battery consumption) and this jump happened.
Maybe if more than one App uses the GPS module the risk for these errorous jumps are higher, but I didn't dare to suspect it this way.

[menion]

hmm test version if you want to check https://dl.dropbox.com/u/8015949/Locus% ... .5.6.4.apk

[PeterPablo]

Since I am abroad the next couple of weeks with uncertain internet access I will refrain from installing this test-version. Or is it save to install it side-by-side?

[menion]

you have also Pro version? Then there will be no problem, just don't try to use them both at once! If you normally use Free version, then rather wait till you'll be home because this test version install over Free version (and also is valid only till end of August)

[PeterPablo]

Yes I am a pro user since five minutes after first app-start ;-)
Ok, then I will give it a shot :-)

[franc]

I installed this beta, tracked oncely but naturally there was no jumping. To test this, I think I would need to track many times. Much more than only several times, because the jumping happens not often.
And endly, how would I know that the gps module jumped while tracking if locus fixes it? Would I even recognize it anyways?
I don't want to track too often with locus, because it uses more battery anyway.

[menion]

hmm no jumps, fine

If it will works fine, then you'll not recognized any jumps. That's the point isn't it? Anyway there still should be some small jumps, not so visible on first sight. I anyway think that it's some software problem, not hardware. Didn't you think about update to Android 4?

[franc]

...If it will works fine, then you'll not recognized any jumps. That's the point isn't it?...

I won't know if there are no jumps because of missing faults of the gps module (or OS software as you thought), or because of the new algorythm in locus. Only if you put some debug message for this case, but I guess you didn't?
And then I guess I had to run the tracking at least for some days again and again to trigger a faulty jump. Like I said, it is not often.

... Didn't you think about update to Android 4?

No, update to Android 4 is not yet an option at all. My OS 2.3.5 works fine, I have nearly no problems with it, very rare only it crashes. Will this be with 4.x the same?
What is the big advantage?
At the moment often I can read in Apps Updates something like "fixed an error for Android 4, made compatible with Android 4, ..." etc. That means, that I could make an OS update in a year or so and then I could hope that all apps are running flawless and stable on 4.x. At the moment I am pretty sure, that this day (or likely more than a day) of work to do this OS update (and all the installing afterwords) is it not worth.
It is nice to have a new GUI but it is much nicer to have a stable system where everything is just working

[menion]

no, there is no error message. Incorrect locations are just ignored ...

about "fixed an error for Android 4, made compatible with Android 4" ... i think it's not that bad. It's just another reason for app publishers, how to update their app on market without any change. They just write this . I think that 99% of apps will not cause any problems. Many people here on forum use SGS2 updated to 4.X android, and I'm sure that most of them may confirm that all apps works correctly

[franc]

no, there is no error message. Incorrect locations are just ignored ...

I thought it.

...It's just another reason for app publishers, how to update their app on market without any change. They just write this ...

Are you sure about this? Why should they do it? People get angry if they have an update every second day because it is time and traffic consuming.

But anyway, can you tell me why I should update my nearly perfect 2.3.5?
Only because it can be, that the rare gps module faults are a software issue? Nobody will guarantee that it will be flawless on 4.x

I had the discussion some weeks ago with a friend, he has an sgs2 as well and we agreed that we won't change the since yet winning 2.3.5-team
Read comments about people who updated and you will find more disappointed posts.
E.g. Titanium Backup apparently doesn't restore all apps, what means that I would have to manually setup many apps I might need, which is a timey thing.

EDIT: I will update to 4.x when the first app needs 4.x as minimum OS.

[franc]

Yesterday I tracked with this Beta and stopped tracking. Some hours later I resumed the same track and my gps found the first two tracking locations 132 km away from where I was, this was tracked by locus beta.
Five seconds later the right point was found and tracked, which made my speed to 26400 m/s. I guess this should not be possible with the new algorythm (even not with the old one).
But looking into my nmea dir I don't find any nmea file from 21.8.2012.
Maybe it has to do with a crashing of locus beta yesterday.

This is a part around the weird tracking from the gpx:

Code: [Select]

...
<trkpt lat="51.321929" lon="9.433191">
<ele>260.97</ele>
<time>2012-08-21T13:04:42Z</time>
<pdop>15.00</pdop>
<course>170.000</course>
<speed>1.65</speed>
</trkpt>
<trkpt lat="51.321699" lon="9.433097">
<ele>262.16</ele>
<time>2012-08-21T13:05:00Z</time>
<pdop>10.00</pdop>
<course>187.000</course>
<speed>1.13</speed>
</trkpt>
</trkseg>
<trkseg>
<trkpt lat="52.064054" lon="7.967058">
<ele>261.60</ele>
<time>2012-08-21T17:24:33Z</time>
<pdop>50.00</pdop>
<course>229.000</course>
<speed>24.52</speed>
</trkpt>
<trkpt lat="52.063354" lon="7.965397">
<ele>261.60</ele>
<time>2012-08-21T17:24:39Z</time>
<pdop>50.00</pdop>
<course>230.000</course>
<speed>24.33</speed>
</trkpt>
<trkpt lat="51.319144" lon="9.440504">
<ele>65.40</ele>
<time>2012-08-21T17:34:44Z</time>
<pdop>50.00</pdop>
<course>172.000</course>
<speed>0.00</speed>
</trkpt>
<trkpt lat="51.318121" lon="9.440638">
<ele>230.46</ele>
<time>2012-08-21T17:34:50Z</time>
<pdop>25.00</pdop>
<course>258.000</course>
<speed>0.00</speed>
</trkpt>
...