[version 3.30.0] GPS position has become highly unreliable and unstable

Menion ●

Good day Max,

sorry to hear about problems with improved GPS system we introduced in the latest version. There definitely is nothing like random offset!

Are you testing it somewhere outside of the building? New system use recommended solution over so-called fused location provider. In buildings, it may return results influenced by a wi-fi signal as well, so I can imagine there will may be some offset.

You are also really only one, who report any problem with this new system till now, so I'm quite sure, it will be some temporary problem on your device.

I'm sorry I can help more. "Unfortunately", to make it simple for developers, fused location provider is quite a black box and there is close to no option, how to influence result.

Hope you find a reason why this happen. Let me know if there will be something I may help with.

Menion

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luca ●

Locus is working perfectly with all my phones since 2011.

Unfortunatly with the latest version of locus GPS is not working at all.

On the GPS screen 0 satelites are detected.

If I launch another app like Strava my position is detected within seconds, but if i switch to Locus still 0 satellites...

My phone is a Crosscall Odyssey+ with Android 4.3

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luca ●

With 3.30.1 version and "compatibiliy mode" Locus is now able to "see" satelites and give my location.

Thanks !

With the new version i've lost my right panel.

First try at home, Locus seems to detect my position indoor, when before it was lost, but with a bad accuracy like 100/200metres. Could be bad for users recording theirs tracks and wanting them acurate. (I know how to deal with it in parameters but not every users)

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Max Moore ●

Good day Menion,

No, I don't use navigation software inside buildings. Why would I? I don't hike inside buildings. Most of the time, and it was the case when I last used Locus Map, I turn off everything (wifi, cell, data) since I am kilometers from any signal.

I might be mistaken but I believe my phone has already its own proprietary algorithm to determine its location, making the "fused location provider (FLP)" superfluous and it might be the reason for the weirdness I observe. I wish a could revert back to the previous version or turn off FLP. But, I can understand the new version is an improvement for most users. it's not entirely a bad thing. I was starting to rely on Locus Map too much any way and neglecting other means of navigation.

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Igor Magellan ●

Also note the deterioration of the stability of the GPS fix in the new version. The fix is lost more often and longer restored under the same conditions. It started in the latest beta version.

Recently I could compare Beta 3.29.2.8 (with new system) and Pro 3.29.2 (with old system). And I like the old system better. Maybe it's because I have a device with a very strong GPS, a pure beast.

Maybe it's worth adding the user's choice to the profile record track or in the "GPS and location":

classical system (old)
advanced system (new)

?

My device: Samsung Galaxy J5 (2016) SM-J510FN/DS

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Menion ●

Hello Max, Igor,

hmm I'm surprised by your negative result.

@Igor, you wrote about lost of GPS-fix. How you detect this? Some sound notification? Change of position circle on the map (from blue to green and back)?

@Max: I did not expect from skilled user to test GPS in the building, but we don't know each yet and from time to time users complain that Locus does not work well in their flat etc,, so I rather ask. Anyway if your device has modified location provider, then it may cause some problems. Fused location provider system most probably use basic location provider in your system and just modify it's output, hmm.

To be true, I hoped it won't be necessary to create an option that Igor mentioned ... some extra settings that allow to switch to the older system.

If you won't kill me ... today we will publish one new bug-fix version. Try it for a while and let me know after week or two. If new system will really cause some troubles, I may add such settings to the system, but I really hope it won't be necessary.

Thank you for understanding.

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Igor Magellan ●

Yes. I have sound alerts on the status of the GPS fix. (in attached ZIP) Because the program works for me every day from almost morning and almost to night, I'm always aware of the state of GPS and its correlation with external circumstances. Accumulated a little experience and a clear knowledge of how GPS behaves in specific conditions.

The simplest experience: settle inside the room near the window. Turn on the GPS in the Locus with the new system. On the windowsill, for example, a clear fix without losses within a couple of minutes. Move it away from the window for half a meter. If all is well, after a minute, move it away from the window yet. Again good? In a minute, move more, etc. Fix was lost! a minute, a little closer to the window .... So you can find the boundary position of the unstable fixation. With the current satellite situation, of course. Now turn on the Locus with the old system. Where the new system showed an unstable fix, the old one will not lose it! So it looks on my device and about such an experience I did with the beta version 3.29.2.8 and Pro 3.29.2.

Of course, I did not immediately begin to do so. At first, I suspected something was wrong when I began to hear the signals of loss-recovery in conditions when nothing like this had happened before. He returned to Pro - and everything became familiar.

I will gladly test a new beta version :)

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Igor Magellan ●

Another experiment is the speed of fixing the GPS fix after a loss

Enter the premises with guaranteed missing GPS signals: the first floor of a multi-storey building without windows, a cellar, a bunker, a cave, a rocket mine. :) Wait for the loss of fixation. A minute later go out into the open space and slowly leave. The old version - fixed fix in 1-2 seconds, and even immediately, and I managed to pass no more than 3 meters. New - 5-10 seconds, and more than 10 meters.

Here is another thought.

I know users who will not watch the accuracy of the recorded track on the map, but will judge the GPS accuracy figure on the program screen and compare it with other programs. And here Locus will undeservedly lose - because where other programs show accuracy of 3m, Locus will show 10m! So the Locus is worse. Although, in reality, the coordinates will be the same, but these users will not be convinced that Locus works no worse - they have figures before their eyes. From purely martquetting considerations, I think it is worthwhile to return the familiar figures.

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freischneider ●

With me that is also with the 10 meters accuracy of GPS. 21 of 22 satellites. Since then I had outdoor field, 3 meters accuracy. In the woods every now and then 4 or 6 meters. But now only 10 meters.

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Condor ●

http://help.locusmap.eu/topic/notification-of-position-gain-gps-fault

GPS (3.30)

There are many different mistakes! For example, the phone is GPS OFF, and yet the notification announces the fix and even the icon is GREEN! When you try to turn on navigation, of course it will be waiting for GPS. Of course, because there is no fix.

Please repair with the highest priority! GPS and its proper functioning is the cornerstone of the application.

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Condor ●

Another screen

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Max Moore ●

Pro and Free (beta) running simultaneously. Still. No movement. Screen capture after 1 minute. 6cd25eac1116078ca5a103264411de38

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Condor ●

New version 3.30.1 no change. All GPS errors remain!

Edit: Mod compatibility seems to work correctly. It would be advisable to explain what it is about GPS chess. Well thank you

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Igor Magellan ●

Condor

Try to enable Сompatibility mode in "GPS and location"

Very similar to the "old mode" of handling the GPS

missed :)

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Condor ●

Thank you ;-) I did this and wrote an edit.

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Lux Calor ●

İnteresting.

New GPS handling: accuracy 10m+, less sattelites are detected, visibly less precise track recording, a little bit faster fix, especially indoors, but gps signal is lost more often.

Compatibility mode: accuracy 4m (the same as GPS Status app), more sattelites detected, more precise track tecording, more stable signal. BUT Locus keeps gps on in the background at all times when the app is minimized, with no track rec on. Which is not convinient.

I have to admit the GPS handling was rock solid before 3.30 on my phone. Very reliable. Not exactly so now.

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Condor ●

Any manipulation of the GPS position that leads to less accuracy is a bad solution. In geocaching, we rely on an accuracy of 2-5m. Pseudo location determination by GSM and Wi-Fi is for whom and why?

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Menion ●

Hi guys,

problem with accuracy: firstly please forget on "Accuracy" parameter visible in GPS screen. This value is simply some abstract number. Comparing of accuracy with old method and new method is also non-sense, because both use different system. Best how to compare accuracy is to make a track records and compare them.

problem with "fix": new method has nothing like "gps fix". In only returns a location from various sources merged into single location. So it is close to impossible to correctly detect if we have fix and if fix was lost. Because of this are here these problems with notification.

problem with GPS in background with compat mode: I'll check it, thanks

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Lux Calor ●

Hi Menion,

1. İt seemed to me the track recording accuracy suffered in same conditions. But I will test more.

2. Even in normal GPS mode (not compat) Locus sometimes keeps GPS on in background after minimizing. Happened a few times this morning.

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freischneider ●

problem with accuracy: firstly please forget on "Accuracy" parameter visible in GPS screen. This value is simply some abstract number.

If it's just an abstract number, then you can leave it out.

I thought since then you can count on the number. If I get displayed 4 meters, my signal is very good. and if I get displayed 12 meters, my signal is worse. and I have to increase the search radius when searching.

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Menion ●

If I leave it, most of users will kill me :).

Consider this as number, that will some probability ( old GPS system defined this usually as around 60% ) say, that your real location is within defined radius. So accuracy 10 in old system say, that you are really on 60 % in 10 m radius. But, I do know this probability in new system! So it is possible that new GPS system (over fused location), say this on 90%/95% for example, and then both values may be almost same if you understand me.

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Max Moore ●

[...] please forget on "Accuracy" parameter visible in GPS screen. This value is simply some abstract number[...]

All numbers are abstract. The same goes for everything displayed on a map. Maps are by definition abstract. They are representations of the terrain. It matters whether symbols, numbers, measurements displayed in the app can be reliably related to something useful and concrete on the actual terrain. If the app displays that we are located in a 3-metre radius around a specific point, we expect to actually be in that probabilistic zone. If it tells us that we are inside a confidence surface eleven times larger (pi*r^2; where r = 10 metres), it matters a lot. It matters that the new version displays 10 metres (95%) where it used to display 3 metres (60%). When I walk near a frozen lake, I need to stay on sure ground. My survival depends on it!

Reliability and accuracy are the main reasons why we use precision instruments, like a GPS. We need the device to tell our whereabouts, to accurately triangulate our location, to have a reliable measurement we can trust, understand and use in conjunction with other tools.

Telling us that we should not rely on the accuracy value, to “forget about it because it’s an abstract number” is a lame excuse. Let me be very clear. I don’t blame you. You are not to blame for the inner workings of the new library of functions. However, you are responsible how you deal with it. You cannot just say it’s abstract therefore nonsensical to expect the app to display reliable, meaningful data, as it previously did.

"So accuracy 10 in old system say, that you are really on 60 % in 10 m radius."

My experience is that the previous geolocation accuracy circle was a lot more 60% reliable. The accuracy number reflected the actual accuracy of my android device. I could consistently rely on it to tell me ±6m 99% of the time where I am when I checked against a known location. I doubt very much the change from 60% to 95% accounts for those huge deviations. That's not what bothers me. What bothers me it that now this number is not proportional to the actual accuracy of my device.

Now, the location jumps all over the map, telling my that I am up to 50m from where I know as a matter of fact I am WHILE displaying an accuracy of 10 m. If it were actually displaying a 95% geolocation circle, IT SHOULD DISPLAY AN ACCURACY OF ABOUT 50 m. The app basically becomes lost. Telling us to ignore the accuracy number don't solve this fundamental regression. The only solution I can think of (but you are the expert, not me) is to add a setting to bypass/disable the guesses made by algorithm.

My guess is the algorithm takes in account far too much other sensors (accelerometers, magnetometers, gravimeters...) which, depending on the device and the environment (for instance, cold weather), are not as reliable as the algorithm expects them to be. So, if I jump up and down on a fixed spot, the algorithm mistakenly believes I am traveling and it adds steps in the direction the e-compass points to.

I was very happy how fast and how accurate Locus Map was. What the app displayed matched what I saw on the terrain. Now, the app tells me I am not where I know I am and that I shouldn’t trust it. It even contradicts itself! When I run in parallel both the pro and the free versions (see my previous post), it tells me I am in two different geolocation accuracy circle. If taking into account other sensors confuses the app, I am not interested in the “(con)fused location provider”.

Last comment. With long-term (greater than 2 minutes) GPS averaging software, I managed to get ±0.6 m accuracy while standing still. In the same condition, the new "(con)fused location provider" displays sporadic movement! It infers movement where there is none. Possibly because temperature variations and battery levels greatly affect some sensors.