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GPS + GLONASS + BeiDou + Galileo


Viajero Perdido

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Hi Everyone.

 

I think it's time to upgrade my caching phone, as the GPS performance seems to have tanked.  Maybe the antenna's come loose inside, I dunno.  Anyway, I got 3.5 good years out of it, so I'm shopping.  And the one I'm looking at supports four satellite systems, which I gather are all the systems currently known to exist.

 

Does anybody have experience caching with a 3- or 4- system device?  Is there a noticeable improvement?  Does the caching app you use even acknowledge the extra satellites?  Does Android (say 9 or 10) allow the disablement of a system or two if, say, there's a trade- or shooting war involving the country operating said system?  (Because that country may fuzz signals as they see fit...)

 

Technology-wise, these are exciting times.  :)

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The caching apps get the current 'best fix' from the phone irrespective of the satellites that the phone used to get that fix.

I have not yet seen an Android phone with the capability of toggling on/off any particular satellite constellation or augmentation system.  It is unclear whether that is because the OS has no control over the GPS function at that level or whether the feature just isn't being offered.

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Another thing to consider before buying is whether the phone manf'r supports the constellation in your market area.  The chipset on my LG=V30 cellphone is Galileo capable, but LG has not enabled it in the US market.

From LG: "According to our resources, the LG V30 H932 phone is designed exclusively with A-GPS technology for enhanced
location accuracy. While the chipset is said to be compatible with Galileo GNSS for Europe, this is yet to be
supported by the LG V30 H932 phone model as it's made for the U.S. market. Other V30 models or counterparts
from Europe may support this technology based on their location."

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Government interference I suppose, thou shalt not use...

 

It may explain why there's an EU and non-EU option for that phone.  The cellular frequency bands appear to be the same, so maybe the difference is in the GNSS enablement.  Or simply the power plugs, dunno.  But...  they do mention quad GNSS in their marketing, with no asterisks in sight.

 

Buying from AliExpress, the target market seems to be "the world", so government factors (other than Chinese) don't seem to come into play.

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No, because even the more recent Garmin units support both GPS and Galileo.  No reason a phone can't.  You don't see Garmin selling different constellation reception to different markets.  Of potential interest >> https://www.gsa.europa.eu/newsroom/news/test-your-android-device-s-satellite-navigation-performance

 

As for the EU non-EU specs for that phone, we don't use exactly the same cellular frequencies, nor do we use the same protocols on the same frequencies (e.g., GSM vs. CDMA).  Not even a 'tri-band' phone covers all of each others' standards.

 

FWIW, even my older Galaxy S8 claims to support GPS, Galileo, Glonass and BeiDou natively.  I've only been able to confirm GPS and GLONASS using GPS Test Plus.

 

Edited by ecanderson
  • Helpful 1
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"...earth stations in the US are allowed...", not the same as enabled.  Check the fine print before you buy.

 

Response from European GNSS Service Centre (GSC) regarding the LG-V30 (above):
"According to Waiver of Part 25 Licensing Requirements for Receive-Only Earth Stations Operating with the
Galileo Radionavigation-Satellite Service of FCC and Released on 16th November 2018:
…to permit non-Federal earth stations within the United States to operate with certain signals from the
Galileo GNSS without an earth station license or a Galileo GNSS market access grant.
That means that earth stations in the US are allowed to operate with Galileo E1 signal (1559-1591 MHz
band) and Galileo E5 signal (1164-1219 MHz).
The chipset makers were all on board to activate Galileo as soon as the FCC waiver entered into force.
Therefore, we regret to inform you that we have no information if LG has activated Galileo in its devices. In
the meantime, we recommend you to contact directly this manufacturer asking if Galileo signals are or will
be enabled in their devices."

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@jakewa

Depending upon the density of the tree cover and how juicy the leaves are, you may be looking for a device that isn't available to you yet.  The attenuation can be quite remarkable, and signal to noise ratio isn't in our favor at the levels these things need to operate.

 

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For now, yes, though the physics of the thing may well keep things this way for a while.  Signal to noise ratio isn't something that the GPSr itself can change.  Ability to pull signal out of the noise has always been the trick.  More sensitivity on the GPSr side isn't the answer (that just brings up the noise with the signal at this point), and they can't change the output power of the satellites that are already up.  So we're stuck with more and better signal processing as the only interim solution.  It's certainly not as though the chip manufacturers aren't working on it, but I suspect they're continuing to work on more pressing problems (like multipath errors) for autonomous automotive navigation first.

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5 hours ago, ecanderson said:

As for the EU non-EU specs for that phone, we don't use exactly the same cellular frequencies

 

Understood.  The phone I'm looking at, being a recent model, has such a long list of supported cellular bands, that I suspect they can handle *all* the world's regions with a single chipset.  This is good; I love to travel, and will again at the soonest possibility.

 

5 hours ago, ecanderson said:

FWIW, even my older Galaxy S8 claims to support GPS, Galileo, Glonass and BeiDou natively.  I've only been able to confirm GPS and GLONASS using GPS Test Plus.

 

This is the interesting part.  So, four bands theoretical, but only two in practice.  I wonder what's holding up the other two: a firmware update from the phone vendor maybe?

 

If I buy the four-GNSS phone (still wavering), I'll report back on what I find.  Thanks everyone for the feedback!  B)

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8 minutes ago, Viajero Perdido said:

Understood.  The phone I'm looking at, being a recent model, has such a long list of supported cellular bands, that I suspect they can handle *all* the world's regions with a single chipset.  This is good; I love to travel, and will again at the soonest possibility.

 

This is the interesting part.  So, four bands theoretical, but only two in practice.  I wonder what's holding up the other two: a firmware update from the phone vendor maybe?

 

Yes, definitely theoretical vs. reality.  Evidently the phone provider has some spec control over whose constellations are actually available for obtaining a fix, irrespective of the native capabilities of the GPS chip.  Not sure what that's really all about. 

 

There's a similar issue to the same phone supporting different cellular bands.  If you're getting your phone FROM a provider and not the manufacturer, do check to see which cellular bands are (as you said above, "in practice") supported by them.  THAT is where the rubber meets the road.  My Galaxy S8 can natively support 31 bands!  ( https://www.frequencycheck.com/models/AabYB/samsung-sm-g950f-galaxy-s8-td-lte-samsung-dream#frequencies ) You probably saw a similarly large list.  However, as delivered from Sprint, nowhere near all of them are available.  The good news, however, is that mine does support GSM (though not with speedy data), and I get decent coverage in Europe and other parts of the world.  What they actually support of the full 31 are the following 23:

 

2G GSM: GSM850, GSM900, DCS1800, PCS1900

3G UMTS: B1(2100), B2(1900), B4(AWS), B5(850), B8(900)

4G FDD LTE: B1(2100), B3(1800), B4(AWS), B5(850), B7(2600), B8(900), B12(700), B18(800), B19(800), B20(800), B25(1900), B26 (850), B28(700)

4G TDD LTE: B41(2500).

 

Sorry for wandering into cell land.  But the point of the above is to note that whatever specs you may see for a phone from the manufacturer, if you get it from a carrier, understand that not all of the phone's native connectivity may be available to you, either GPS or cellular.

 

 

 

 

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Why on earth would I buy a phone from a carrier?  :P  Decades of abuse from carriers, at least in North America where I live, have made that idea a non-starter.

 

I count 39 cell bands for the late-model phone I'm looking at.  No matter where I go, at least one or two of those should work.  PS, it's dual-SIM and unlocked, of course - what you'd expect from a non-carrier phone.

 

Edited by Viajero Perdido
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3 hours ago, ecanderson said:

For now, yes, though the physics of the thing may well keep things this way for a while.  Signal to noise ratio isn't something that the GPSr itself can change.  Ability to pull signal out of the noise has always been the trick.  More sensitivity on the GPSr side isn't the answer (that just brings up the noise with the signal at this point), and they can't change the output power of the satellites that are already up.  So we're stuck with more and better signal processing as the only interim solution.  It's certainly not as though the chip manufacturers aren't working on it, but I suspect they're continuing to work on more pressing problems (like multipath errors) for autonomous automotive navigation first.

 

What if a GPS hardware producer were to offer a device using both L1 and L5 bands simultaneously? And then from multiple GNSS networks simultaneously?

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I think we've discussed L5 before here.  When it actually goes truly into service in a few years, my current phone's chip can handle that, too... but by that time, I'll likely have a different phone, and most new ones will be supporting it anyway.

 

But we're talking S/N ratio here.  L5 signals don't have any more ERP than L1, nor will the 400MHz lower frequency do that much better at penetrating water (which is the root of the 'canopy problem').  If all of the signals are weak due to dense canopy, it's still a problem.  The problem is seriously compounded if the canopy is wet from rain.  So I wouldn't expect a big improvement there.  I'm still betting on better digital filtering to try to find the signal from what little gets through.

 

Looking forward to L5, though, as this should provide faster locks, some improvement in positional accuracy, and less multipath errors, especially in urban 'canyons'.  Autonomous vehicles won't be the only beneficiaries -- urban cachers definitely will be, too.

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I just ordered the quad-GNSS phone I'd mentioned, and I'll report back eventually on what I've found.  Would've probably bought that one anyway, but the quad-GNSS thing was extra incentive.

 

In the meantime, this thread has taken on a bit of life of its own, and that's fine.  I'll sit back and absorb what I can.  Thanks folks!  B)

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That tool mentioned earlier for determination of GPS signal quality and other goodies is free (if you don't get the 'plus' version) and will let you filter for any of the several GPS systems out there so you can tell us what you actually have!  Better yet, a proper pointer >> https://play.google.com/store/apps/details?id=com.chartcross.gpstest

 

I haven't been able to look at the phone you are ordering because promo.blackview.hk  doesn't seem to be responding.  Seems to have some issues at the moment.

Edited by ecanderson
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Hmm, that link works for me.  But there's actually more info on their AliExpress page, which is here:  https://www.aliexpress.com/item/4000781059595.html

 

My current phone is a low-spec Blackview rugged phone (BV6000s), a discontinued model that's served me well.  So I have no qualms with buying that brand again.  Stay tuned!

 

And yes, that GPS Test app* is great.  I've been playing with it today, trying to figure out what's wrong with my current phone (did all the abuse loosen something inside?), and why is the even older phone that preceded it still working so well?)

 

(* Correction: I've been using "GPSTest", no space in name, different app.  I'll look at the spaced-out version.)

 

Edited by Viajero Perdido
Devil in details
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There wouldn't be noticeable improvement on the cache find rate, even if your unit was accurate down the millimeter, and that's because you are reliant on the accuracy of the person who placed the cache.  Any GPS unit or any half-decent phone will get you close enough to ground zero. The geocaching format MM.xxx means at best, the real accuracy can only be within 6 feet at best. To require more accurate than that, would have to be MM.xxxx or better. 

 

 

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Very true gpsblake.

 

Even on your best day your device accuracy may be off 8-15 feet in any direction, while the hiders device could have been off as much or more in the opposite direction, leaving us all with a best case scenario of about 20-30 feet in any direction on average.

 

I always say; "Once you are within 30 feet (10 meters) of ground zero, it is time to put the GPSr down and start using the fancy computer between your ears!"

 

However, there is an important difference between accuracy and precision.

 

precision-vs-accuracy.png.03ac20f5bb08098d213a2a867c91f049.png

 

When dual frequency receivers do become available, they will be more accurate and more precise, especially in scenarios where multi-path has been an issue in the past.

 

2019143467_SingleBandvsMulti-Band.png.3fc495006d5ff5868e1ae6a5dc4749c9.png

 

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18 minutes ago, Atlas Cached said:

When dual frequency receivers do become available, they will be more accurate and more precise, especially in scenarios where multi-path has been an issue in the past.

 

That's the company line, and I sure hope it's true.  While things have improved over the years, between the buildings blocking a large part of the constellation to begin with, and then reflecting signals all over the place from the ones that can peek in, it can be extremely hard to get an adequate (much less geocaching good) fix in some urban areas now.

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I checked out the app mentioned above, but I think I still prefer GPSTest, as it shows a national flag beside each satellite, allowing you to see which constellation(s) you're getting.

 

It also shows some interesting flags for each satellite.  And curiously, on my device that's been performing poorly (destined for the drawer once the new phone shows up), of the 8 or 9 satellites it receives weakly, none show the "A" or "E" flags.  Ever.  Meaning, no almanac data nor ephemeris data, yet "U" says they're used in the fix.  I didn't realize that's even possible.  My older phone that performs well (both are Android 6) does show these flags for each satellite, and more satellites too.  Curious.

 

BTW, it seems you can't receive Galileo in the US, because government.  Well actually you should now, but maybe not in your phone.  Seems to be a function of your location, not the country where you bought the device.  There's an interesting thread about that issue here.

 

Edited by Viajero Perdido
Spellling
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37 minutes ago, Viajero Perdido said:

I checked out the app mentioned above, but I think I still prefer GPSTest, as it shows a national flag beside each satellite, allowing you to see which constellation(s) you're getting.

 

It also shows some interesting flags for each satellite.  And curiously, on my device that's been performing poorly (destined for the drawer once the new phone shows up), of the 8 or 9 satellites it receives weakly, none show the "A" or "E" flags.  Ever.  Meaning, no almanac data nor ephemeris data, yet "U" says they're used in the fix.  I didn't realize that's even possible.  My older phone that performs well (both are Android 6) does show these flags for each satellite, and more satellites too.  Curious.

 

BTW, it seems you can't receive Galileo in the US, because government.  Well actually you should now, but maybe not in your phone.  Seems to be a function of your location, not the country where you bought the device.  There's an interesting thread about that issue here.

 

 

Wow, thanks for making the best case yet for using a dedicated GPSr instead of a mobile phone... All my Garmin GPSr receive and use Galileo satellite signals without issue!

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Exactly, Atlas.  There are definitely devices currently designed and sold in the US that are not just capable of employing, but actually do employ Galileo satellites for a GPS fix. The phone manufacturers are all way behind the power curve.  https://www.gsa.europa.eu/newsroom/news/fcc-approves-use-galileo-us

 

Edited by ecanderson
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4 hours ago, Atlas Cached said:

Wow, thanks for making the best case yet for using a dedicated GPSr instead of a mobile phone...

 

I think I made the best case yet for using newish hardware.  :P  It's been ~2 years since the US gov't got out of the way, so people should start seeing the effects in newer hardware by now*.

 

The no-Galileo-for-you saga could also make the case for not caching in the US, and not buying hardware there or from a company domiciled there.  Check, check, and check.  :)  I've improved the odds as much as I can, now I just have to wait for the package, and fire up GPSTest again.  I'll report back.

 

(* ...or sooner, if the hardware manufacturer never bothered blocking it by law.  Possibly, point to Garmin.)

 

Edited by Viajero Perdido
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3 minutes ago, Viajero Perdido said:

The no-Galileo-for-you saga could also make the case for not caching in the US, and not buying hardware there or from a company domiciled there. 

 

This makes no sense what-so-ever to me.

 

1. Geocaching was invented in the U.S. (you're welcome)

2. Garmin (based in Olathe, KS) produces excellent GPS receivers that work with GPS + GLONASS + Galileo + QZSS + BDS + NavIC + WAAS + EGNOS.

 

Why would you not cache in the US, or not buy any hardware from a US producer because of a slow decision by the FCC?

 

 

 

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  • 1 month later...

A slow boat from China has docked (~1 month, no other shipping option), and I'm the happy owner of a new Blackview BV9900 Pro.  First impressions, really good, and I think the Helio P90 chipset gets credit for this screenshot from GPSTest:

 

Screenshot_20201018-133527.thumb.jpg.8b0b346fd972eae81ffedbadfabb9bc5.jpg

 

Four constellations all contributing to the fix!  Also (off the screen), WAAS is being received but oddly, there's no U flag indicating it's contributing to the fix.  The app shows it cycling through about 6 different SBASs trying for a signal, but here in Canada, only manages to find WAAS.

 

I took a bike ride and recorded a track, which matches the roads pretty well.  Haven't taken it for a real caching run yet, but expect the results will be good.

 

Since folks asked, here are a few first impressions.  First off, it's heavy, a sturdy brick, likely thanks to the big battery.  You could kill somebody with this phone and only have to wipe it down.  And it's slippery too, so be careful if you wear sandals.  But really, I'm praising with faint damnation; I like this thing.  It has a quality feel to it.

 

In the pictures below, the new phone is on the right, next to my malfunctioning BV6000s.  What surprised me is that their dimensions are almost identical.  But the new phone has less bezel and more screen, and it's a nice high-res screen compared to the old cheapie.  The app is Locus Map Pro working offline (haven't put in a SIM yet) showing some offline OSM maps.

 

P1230588.JPG.1c25c0776b74636448c9cc08e60b521c.JPG

 

P1230587.JPG.3b0a8091c5e08fe65954139ab2b75aec.JPG

 

Notice reported accuracy: 1.1m (3.6'), and that's indoors.  I can use that.  B)

 

Edited by Viajero Perdido
Persnickety little detail
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On 9/8/2020 at 7:14 PM, Viajero Perdido said:

I think it's time to upgrade my caching phone...

 

Looks cool.  I'd miss those pool table-like bumpers though .    :)

I'll probably pick up an iphone12 mini and stick it in an otter box,  since my rugby smart flip's finally going bye-bye when 3g is done...

 It supposedly has "support for" GPS, GLONASS, Galileo, QZSS, and BeiDou satellites.

Guess if I ever need to use it for caching it'll work okay .

 

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15 hours ago, Viajero Perdido said:

Haven't taken it for a real caching run yet, but expect the results will be good.

 

Nice phone! Maybe off-topic, but could you at some time in the future give your thoughts on the accuracy of the electronic compass when using a geocaching app (e.g. Geocaching4Locus)?

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On 10/18/2020 at 6:29 PM, Viajero Perdido said:

 

Screenshot_20201018-133527.thumb.jpg.8b0b346fd972eae81ffedbadfabb9bc5.jpg

 

Four constellations all contributing to the fix!  Also (off the screen), WAAS is being received but oddly, there's no U flag indicating it's contributing to the fix.  The app shows it cycling through about 6 different SBASs trying for a signal, but here in Canada, only manages to find WAAS.

 

 

Does the BV9900 Pro allow you to set a higher satellite masking angle?  From the screenshot it looks like it is factory set at less than a 5° angle.  Since you really only need four well spaced satellites to get an accurate solution these should be easier to attain with such a large number of available satellites.  A higher masking angle of 25° to 30° would mitigate multi-path errors and atmospheric refraction to produce a smaller (better) DOP.  I'm assuming it is possible to combine four satellites from different constellations.

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On 10/19/2020 at 8:21 AM, Lilski said:

thoughts on the accuracy of the electronic compass when using a geocaching app

 

Gave it a little test outside in the yard just now.  Did the figure-8 calibration wiggle, then had it point at a cache.  Spun around (me + phone), and the compass did its job, keeping the arrow pointing (roughly) toward the cache as it spun.  My street is lined up with the compass points, and would say the compass was off by about 20 degrees.  (Away from the city, maybe better, haven't tried.)  But I can live with that.

 

On 10/21/2020 at 3:09 PM, Capt. Bob said:

Does the BV9900 Pro allow you to set a higher satellite masking angle?

 

I'm reasonably sure that's outside the user's control, and I'm not even sure Android has access to it internally.  The GPSTest author seems pretty knowledgeable, and if there were tuning parameters you could tune, he'd probably add them to the app.  You can "Inject PSDS data" (not available with this phone) and "Inject time data" (available) to goose the accuracy a bit, that's all.

 

On 10/21/2020 at 3:46 PM, Atlas Cached said:

That should just be a list of all satellites the device can see, not a list of all satellites used to compute location.

 

It looks like a list of all sats currently above the horizon (even by 1 degree), and the "U" flag indicates it's "used in calculation of the most recent position fix", per the help.  So yeah, I count 29 "U" flags in that screenshot.  B)  ... Just got back again from the porch; it got up to 23 before I got cold and came back inside.

 

Still haven't used the thing for actually finding caches...  EDIT: Ah yes, it rocks for finding caches!  :wub:

 

Edited by Viajero Perdido
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  • 2 months later...

I’ve been using the BV 9100 - the 4 satellites with a humongous battery.  For other reasons I recently purchased a phone with a dual-frequency gps.   I doubt that any increased accuracy with the dual frequency will make a difference for the purposes of this game, but when I have a chance it will be interesting to compare them.  

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