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GPS + Glonass

Tigus shared this question 10 years ago
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Hi , maybe this question does not involve itself with Locus , but the program I use and love it.


I would ask them if anyone has experience using Locus in changing from one mobile device that has only GPS to one having GPS + Glonass .


In my case I used a Galaxy S2 with GPS and records were accurate , very accurately.


I am now using a Galaxy Xcover2 (I love :)) with GPS + Glonass , but ... registration is not accurate at all ... very bad . traced routes to places I can not move (except Superman flying :)) .


When I consult the precision with which such a point that is not in the right place as I did the tour , was recorded the accuracy of the point is not so bad, eg 15 meters, however is much greater distance of travel real than the 15 meters.


Can influence which also use Glonass ?


Any help, suggestions , configuration , reading to do?


In case it helps, I have for same tour a GPX registered with the S2 and GPX registered with Xcover2.


I am in Mendoza - Argentina , for if it helps my location .


From already thank you very much .


Greetings .

Replies (25)

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I use a SGS 3 which has also GPS+Glonass and before I had a SGS 2 as well.


My experience is that both have pretty good detection of location but the circle showing the alleged accuracy does not always cover the real current location. This behaviour I have already seen lot`s of times e.g. when my phone is sitting without movement under a roof-light.


My location is in Bavaria/Germany.

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I also had no problems with Note 2 devices (which also use both GPS systems at once).


Do you have problems just at start of using GPS or for a whole time? I mean just few minutes after you enable Locus or for a whole time?


Anyway, if you device use GPS and also Glonass at once, it should be generally much much better then just using American GPS on your SGS 2. You should at least see much more visible satellites on GPS screen, do you?

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Hello, Tommy and Menion . First of all thanks for the prompt reply .


Trying to shed some light on the subject and answer , the problem of accuracy in location not given only at the beginning , but throughout the course , in some places more , in others less.


What strikes me is that the number of satellites is fixed and looks good , about 10 or more. And even the accuracy is very good points , in general 5-15 meters.


As my attention so bad that records the XCover ... being with GPS + Glonass should be more accurate , which was my intention with changing device ...


Attached path stored with the same locus with the SGS2 and the XCover2 , at different times , so that you can see the difference ... I do not even test to make the trip with the two teams at once.


I`m starting to think it may be due to a hardware failure :( , what surprises me since fixed with good accuracy and satellites ... baffled.


Any help or test I can do will be appreciated.


Greetings .


SGS2:


https://dl.dropboxusercontent.com/u/7...


XCover2:


https://dl.dropboxusercontent.com/u/7...

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Hi, I attached some pictures to better explain the problem. I have to bring bad ...


The tour I did in the street painted yellow, however the recorded trace will oddball out of the street, as you can see by the example of point 130, the information says precisely five meters, so I do not get as accurately locate me that the path about 100 meters from where I actually was.


Any hints, configuration, test can reach me a hand?


O is definitely hardware problem?


Greetings.

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just to notify you that I precisely read your post - sorry, but I have no idea how to help here. Locus do no optimizations on coordinates, so if there is any problem with location, it`s not on side of Locus.


For me, it simply look as bad configuration of satellites (if this happen really rarely), or bad hardware (GPS unit) in your device.

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Menion Thanks for replying, I`m pretty lost on this issue ...


According to what I comets could be reached (it simply looks as bad configuration of satellites (if this happen really rarely)), you have any idea how can you change? You mean the A-gps data? The Android location settings I indicated that only use the gps as a source location.


Again, thank you very much for the contribution.


Greetings.

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I`m checking your GPX files from this post ... https://getsatisfaction.com/locus/top...


Seems that SGS2 do not have so bad precission, it mainly react quite slowly on changes in direction.


I also have SGS2 that I use and from my experience, ROM has also influence on GPS. Mainly on speed how quickly you get fix.


Tigus, I generally do not know what to do with it. I`m not experienced with ways, how work different GPS chipsets and what should affect GPS precission. But if I had such device and have time to play with it, I should firstly check other programs, to be really sure it`s not a problem of one I use. And if I found that it`s really problem of device and not any program, then I should try any alternative ROM. There is quite a lot of them out there ...


just my opinion. Sorry I cannot be more helpful

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ah btw. ... hardware GPS, two years old and only using American GPS satellites, not Russsia Glonass, is precisse in good!! conditions (open sky) around 15 - 25m. Not better. In rare cases up to 10 meters, but in normal condition count with values around 25m. Do not trust values in locus that say "accuracy: 5m". Locus just display these values as they come from Android system, but they lie for sure ;)

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Hello Menion, again thank you very much for the replies.


Maybe I misspoke in my previous post (English is not my language), but the SGS2 trace routes very well, the device I`m testing is a Samsung XCover2 having GPS + Glonass. XCover2 mapping is wrong (https://getsatisfaction.com/locus/top...) ...


I`ll try some other application to record routes, but I doubt it`s an issue of Locus ... in fact, I do (Locus fan, it`s my main application). Any application that you can suggest me?


Thanks for the tip of the ROM, I`ll remember. For now the XCover2 is with stock ROM, only rooted with http://www.kingoapp.com/.


I`m almost leaning toward hardware problem. Theme GPS settings and files themselves do not know, find something else on google.


Greetings.

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ah I`m very sorry ... I have switched your devices. Sorry ... because now my previous post do not have much sense. I though you have problems with SGS2 ...


Tehn I have absolutely no idea - XCover2 uses more satellites, it`s not so old as SGS2 right? And on same track at same time, it has worst precission then SGS2


So if no-one has any better though, then from my point of view, on 90% it should be hardware problem. I suggest to simply check MyTracks or any other app that record tracks. MyTracks is from Google team so it should be good reason to trust it ... good luck!

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Menion Thanks, I`ll tell you the latest news as it serves as information to someone else.


Greetings.

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I think I have the same problem, also using a Xcover2.


When using Locus with track recording then after a while (maybe an hour) the position deviates from the real one about 50 meters, usually lagging behind. It does not correct automatically, one time it did after standing still 10-15 minutes.


When I turn the gps off and on (either via Locus or via Android) the correct position is back (you see a jump in the track), but this deviation comes back ever more frequent.


When I do not use recording there is no problem (then the gps is turned off and on automatically when the screen turns off).


When using another app (Bikecomputer Pro) with recording a longish time I also did not experience this problem.


I hope this helps to determine whether it could have something to do with Locus or not.


Thanks, Frans

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Frans Thanks for the input, really makes me "happy" knowing that someone else with this problem, I`m not alone in the world with XCover2 :). Of course it would be better if there were no problem :).


Coincidentally, I also did the tests recorded.


Please I ask you notify me if you find any solution or have any news about the issue, I`ll do the same.


Greetings.

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Did some more testing during a walk (slow speed):


I found that the problem of lagging behind some 30-50 meters happened frequently and was only resolved by turning gps off and on.


I tested with both Locus Pro and BikeComputer Pro and the problem occurred in both apps, albeit a bit differently: with Locus is appeared very quickly and often and it is not corrected at all, with BC it didn`t appear as quickly and it was often corrected in the following peculiar way: When it lags say 50 meters and I made a 90 degree turn, the position slowly crept towards the right position, i.e. the recorded track made a shortcut (like the long line of a triangle). With Locus it didn`t do that: the track also made a 90 degree turn and remained parallel to the actual course 50 meters off.


Thus, the problem occurs with both apps, but not the same.


(When using BC on a ice-skating ring (with cycling speed), the problem does not occur)


The shortcut phenomenon makes one think that there is a sort of stabilizing mechanism, anything to do with the gps chip`s static navigation feature (I was moving at walking speed)?


Because turning the gps off and on reset the correct position, I then tested it with Locus setting GPS-auto-off, first with the default numbers but that resulted in a very course track, later with a 10-second interval. This resulted in a less accurate track but the lagging problem seems to be gone.


Does anyone have a suggestion for good gps-auto-off settings, or have any thoughts on this issue? Thanks.


Frans

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Hi Frans.


Just the way you describe the situation is what happens to me, it shows that there is a delay in taking direction changes, even given certain changes in direction, in my case east / west, not north / south.


I have read that it is with the Samsung S3 mini, apparently shares the hardware with XCover2.


http://forum.xda-developers.com/showt...


One suggestion I read and yet I taste is https://play.google.com/store/apps/de... . trekbuddy.midlet & hl = es, but I do not make the case.


If I have any novelty, will discuss ... I do not like the idea of ​​myself to be a hardware problem. Samsung has this phone for outdoor activities such as off-road, so the GPS should be very very good.


Greetings.

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Just a guess... did you try to reset "assisted GPS data"?


It`s explained at the very bottom of this page:


http://support.locusmap.eu/hc/en-us/a...

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Hello Berkley.


I tried reset the AGPS data, but it has not helped ...


Thanks for the suggestion and link.

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The links you gave seem to suggest to assure that the gps chip remains active, while I think the problem goes away when the chip is turned off and on, either manually or automatically using the Locus gps-auto-off setting.


I also think it is not (only) a hardware problem as two apps behave differently and an app can circumvent the problem by switching the gps off and on.


Will you try to do a test with the gps-auto-off setting and see if that works satisfactory?


I still wonder whether the problem occurs only at walking speed or also with cycling speed. I will test this shortly.

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Thanks for the suggestion but if I understand it correctly, the reset AGPS is to retrieve the satellite ephemeris data from an internet server, rather than from a satellite (which is very slow), and is only meaningful to get a quicker fix at the start.

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Hi Frans, I agree with your comment.


When you can do the test with "gps auto-off", commented on the results.


On the other hand, took the phone in for tecnical service and was told that no hardware problem, apparently tried it with the car going on "Maps app" and they said doing well. Much more on this side I can not do.


Cheers and continue with the tests.

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I did a test with cycling speed, with the gps chip constantly on: perfect recorded track! i.e. the problems appears to occur only at slow (walking) speed.


Is this also your experience?


The self-correction I saw with the BikeComputer app (after a 90 degree turn slowly creeping towards the correct position) now also seen with Locus, so it seems a gps-chip or android "feature".

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Hi Frans, as is what you say, is the same. I tried going by car does not give problems. Apparently it`s the low-speed directional changes.


What I have not tried yet is change the configuration to use compass, magnetic or GPS, to see whether or not influences.


Have you tried calibrating the compass? It can be from Locus?


Greetings.

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Frans, you tried Google My Tracks in XCover?

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Hi Tigus, I`m not sure what you mean. The problem I have is that the current position lags 30-50 meters (when moving slowly) and hence the recorded track is inaccurate. What you seem to refer to is that the arrow direction is not always correct when moving slowly. That is normal and is the case with all gps devices.


No, I have not used MyTracks as I want to use offline maps.

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Hi Frans, you describe it as such, I have the same problem at slow speeds. I mentioned the issue of the compass as for testing, I do not know if it may influence the layout of the route.


Off topic:


You`re the same Frans (http://forum.xda-developers.com/showt...)? If so, thanks for the input, I deactivated the function also turn the flashlight with the volume key as it kept the device awake.


Hopefully soon there is a ROM update from Samsung.

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