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fizzymagic

Incorrect accuracy display

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As far as I can tell, the Android app indicates a position error of at least 10 m, even if the underlying system reports a better accuracy.

 

My guess is that this design is intended to keep newbies from expecting better performance than is realistic for the GPS position.

 

However, the design is a bad one, as a more experienced cacher is unable to assess the true accuracy of the GPS unit.  Wiring apps like this to always appeal to the least common denominator is likely to lead users to believe that Groundspeak is incompetent, when in fact the app is merely mendacious.

 

Please fix this problem.  Thanks.

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8 hours ago, fizzymagic said:

As far as I can tell, the Android app indicates a position error of at least 10 m, even if the underlying system reports a better accuracy.

 

My guess is that this design is intended to keep newbies from expecting better performance than is realistic for the GPS position.

 

However, the design is a bad one, as a more experienced cacher is unable to assess the true accuracy of the GPS unit.  Wiring apps like this to always appeal to the least common denominator is likely to lead users to believe that Groundspeak is incompetent, when in fact the app is merely mendacious.

 

Please fix this problem.  Thanks.

I have noticed that too. Mine is always fixed at that same accuracy (10m/33ft) while all the other apps including GPS status will report an accuracy that varies. If the reported accuracy is going to be fixed at 33ft, why bother reporting it at all? Especially if it is not correct?

compass.thumb.jpg.0b5f00e3f96b4f52ef402d20d9693f47.jpg

 

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The exact same issue showed up in Locus Map recently, when the developer switched to a different system of interfacing with the GPS receiver, "fused location provider", a system that should have offered better reliability.

 

http://help.locusmap.eu/topic/how-did-version-3-30-get-a-more-accurate-gps-location

 

It was a headache, so he switched back.

 

10m was a byproduct.

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1 hour ago, Viajero Perdido said:

The exact same issue showed up in Locus Map recently, when the developer switched to a different system of interfacing with the GPS receiver, "fused location provider", a system that should have offered better reliability.

 

http://help.locusmap.eu/topic/how-did-version-3-30-get-a-more-accurate-gps-location

 

It was a headache, so he switched back.

 

10m was a byproduct.

 

You're missing the part where he said "despite the fact that mobile phones technically can't acquire better GPS accuracy".

10m is the most accuracy that a standard phone GPS can provide. Even if the sensor thinks it has a better reading, 10m (4 decimal places) is the margin of error

 

The app itself doesn't actually do anything to cap the displayed number; the phone itself never reports a higher accuracy than 10m.

 

Besides, if you get within 30 feet, it's time to start looking with your eyes!

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19 minutes ago, rocketgarden said:

The app itself doesn't actually do anything to cap the displayed number; 

 

The app seems to be doing exactly that. While all the other apps report varying accuracies at any given time and circumstances from as low as 2 or 4 feet up to 100 feet or more, the official GC app on android locks in on 33 feet and doesn't change.

 

19 minutes ago, rocketgarden said:

the phone itself never reports a higher accuracy than 10m.

Absolutely not true as the other GPS-related apps on my phone indicate otherwise. 

20 minutes ago, rocketgarden said:

Besides, if you get within 30 feet, it's time to start looking with your eyes!

The issue isn't difficulty in finding a cache, the issue is being annoyed with a bug in the application.

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2 hours ago, rocketgarden said:

 

You're missing the part where he said "despite the fact that mobile phones technically can't acquire better GPS accuracy".

10m is the most accuracy that a standard phone GPS can provide. Even if the sensor thinks it has a better reading, 10m (4 decimal places) is the margin of error

 

The app itself doesn't actually do anything to cap the displayed number; the phone itself never reports a higher accuracy than 10m.

 

Besides, if you get within 30 feet, it's time to start looking with your eyes!

 

You are incorrect.  Mobile phones, using GLONASS, can achieve accuracies oa better than 3 m.

 

Also, the phone DOES report a better accuracy than 10 m.  The app artificially caps it at 10m.

 

And the whole "30 feet should be good enough" nonsense is exactly that: nonsense.  I, for one, don't have much use for an app that decides for itself that I don't need accurate information.

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Is it possible that someone from HQ could illuminate the rationale behind this behavior?  Maybe there is something I didn't think of.

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10 hours ago, fizzymagic said:

Is it possible that someone from HQ could illuminate the rationale behind this behavior?  Maybe there is something I didn't think of.

 

Hello! I'd be happy to.

 

Unfortunately, it is the case that the app has no lower limit on accuracy. We are passing through the values that Android's location provider is giving us, no changes or adjustments. It would be nice if we were limiting the accuracy as that would be a much easier explanation of either reasons why, or putting in something in a later release to shut that off, but as it stands currently, that is what the system is providing for the accuracy. The truly unfortunate part is there could be a lot of reasons why everyone is seeing different behavior. I myself have seen the accuracy go as low as 10ft/~3m (and go as high as 116ft/~35m), but on average I see the ~33ft/10m that everyone is experiencing.

 

I saw the mention of GLONASS and went down that rabbit hole of information as well. At the moment, I can't find anything definitive on whether or not the location provider that is available on Android is using it. My assumption is no. I know that certain smartphones are capable of hitting the other satellite providers and getting raw data, but there isn't anything official that I am seeing from Android other than how to get the data and ways to model it (found it here: https://developer.android.com/guide/topics/sensors/gnss). 

 

On 8/28/2018 at 8:45 AM, Viajero Perdido said:

The exact same issue showed up in Locus Map recently, when the developer switched to a different system of interfacing with the GPS receiver, "fused location provider", a system that should have offered better reliability.

 

http://help.locusmap.eu/topic/how-did-version-3-30-get-a-more-accurate-gps-location

 

It was a headache, so he switched back.

 

10m was a byproduct.

 

For this one, I am not sure how to answer this behavior from Locus Map without actually looking at their code (which I am sure they won't let me do since I am a competitor :) ).

From the comments it seems like they are getting raw GPS but that would mean users on pre-2016 devices would not have access to this (like the above link from Android talks about) and the app supports back to Android 4.1. So Locus Map should still be using the regular location provider and should have the same average case of ~33ft/10m. However, this is just me making assumptions based on three comments in a thread, so please take that for what it is.

 

To sum up and answer the original question, there is no filter or limiter added to the accuracy that the app is displaying. Whatever the Android OS sends is what we show.

GLONASS and the other satellite providers are accessible by some Android devices, but I cannot find documentation stating that it is used in their location providers yet (but I am still looking).

For Locus Map, I am assuming that user has had the same experience I have every once in a while, when I am testing, where the accuracy becomes better than the average case of ~33ft/10m.

I am also still looking deeper for something that backs the claim that the FusedLocationProvider limits to ~33ft/10m, like what the Locus Map forum post has shown. That shouldn't happen based on how it works, but I don't have any hard facts to prove or deny just yet.

 

Does this help answer the question?

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3 hours ago, dgruici said:

Does this help answer the question?

 

Boy does it!  Thanks so very much.  So somehow the locations services in Android is limiting the reported accuracy.  It's a relief to me to know that Groundspeak is not responsible!

 

I have another app called "GPS Status" that reports a different (better) accuracy, but the developer there must be using some more direct interface to the GPS hardware. Or a different way of querying the location service.

 

I found some stuff on the Internet that seems to indicate that when you request the location from the Android location service, you specify the accuracy you need.  It seems possible that the returned accuracy is limited by that value.  All this is to try to minimize battery usage., which nis A Good Thing.

 

But perhaps after the app 'dings' that y9ou are getting close, the location could be queried with a smaller "required accuracy" setting and, for the short time that you are searching, it could give better accuracy.

 

Of course, I have only done a little research and I don't know if that is possible but if it is that would be most helpful!

 

Thanks again for your response.

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16 hours ago, dgruici said:

I myself have seen the accuracy go as low as 10ft/~3m (and go as high as 116ft/~35m)

 

I see your 116 ft, and I raise you 199 feet more...the caption on this owner maintenance log photo was, "and this is why I still use a GPSr"

 

087daaea-73f6-41c1-a96f-7507e24b2818.jpg

 

(Things seem much better now that I've replaced my Galaxy S5 Mini with an A6+, for the record, so maybe I just had a crap phone.)

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And this is part of the reason I no longer use a standalone GPS unit:

b36c7c02-cc98-4dfc-849f-f2111cc8a449.jpg

There's no choice in software, and to upgrade brings the small but non-zero risk of bricking the unit.

 

I've also seen this thing be "off" by over 1 kilometer (!) briefly, and occasionally be persistently off by hundreds of metres, necessitating a reboot.  (My phone acts up too, but not as much.)

 

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Update:  This problem is no longer occurring in the updated version of the app.  I am seeing realistic accuracies now.  I don't know how it got fixed, but thanks!

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