Re: Digest for gpstest_android@googlegroups.com - 7 updates in 1 topic

[Костя Стаханов]

Are you involved in the development? Indeed, now you can see a lot of new and very important data about the progress of measurements! Now the application looks much more interesting! Everything has become clearer. 👍 But still, why does the "advanced" Qualcomm not give phase measurements in stock, while the "backward" MediaTek does without problems? It seems to me that it's a matter of money. Qualcomm bought Sirfstar at one time,And there they planned to sell phase measurements...that's why they removed the phase in Sirfstar 3, and added it in 4 because no one wanted to pay for it...I apologize for the historical digression.

С уважением, Константин С

ср, 25 сент. 2024 г., 04:42 <gpstest...@googlegroups.com>:

gpstest...@googlegroups.com

Google Groups

Topic digest
View all topics

• SBAS satellites and other correction systems - 7 Updates

SBAS satellites and other correction systems

Sean Barbeau <barb...@google.com>: Sep 24 07:55AM -0700 See https://issuetracker.google.com/277837966#comment4:   >Due to signal characteristics of SBAS and mobile devices, decoding the Navigation Message and getting a signal of high quality is a challenge. We checked with other chipset manufacturers and no one is using SBAS for positioning at the moment.   Sean   On Monday, September 23, 2024 at 10:50:34 AM UTC-4 k.stah...@gmail.com wrote:

Костя Стаханов <k.stah...@gmail.com>: Sep 24 06:52PM +0300 Please tell me why MediaTek can give phase measurements, but Qualcom can't? Maybe because of this the GPS GPStest:Navigation app gives results with an accuracy of 1 meter? С уважением, Константин С   вт, 24 сент. 2024 г., 17:55 'Sean Barbeau' via GPSTest <

Sean Barbeau (xWF) <barb...@xwf.google.com>: Sep 24 12:02PM -0400 To my knowledge the only device with a QCOM chipset that has supported ADR/Carrier Phase has been the Pixel 4 and 5 series.   You can look this up in the GPSTest Database - see: * https://barbeau.medium.com/crowdsourcing-gnss-capabilities-of-android-devices-d4228645cf25 * https://bit.ly/gpstest-device-database   Let me know if you find other examples.   Sean   On Tue, Sep 24, 2024 at 11:52 AM Костя Стаханов <k.stah...@gmail.com> wrote:

Костя Стаханов <k.stah...@gmail.com>: Sep 24 07:09PM +0300 Thanks for the answer Sean! But that's not quite what I was asking - why do you think MediaTek gives out phase measurements, but Qualcomm doesn't? That's the first thing. And the second thing - maybe because MediaTek gives out phase measurements, smartphones with it show in the program ( https://play.google.com/store/apps/details?id=com.chartcross.gpstest&hl=ru ) an accuracy of 1 meter? С уважением ,Константин С.

Sean Barbeau (xWF) <barb...@xwf.google.com>: Sep 24 12:33PM -0400 > why do you think MediaTek gives out phase measurements, but Qualcomm doesn't?   I suggest reaching out to the chipset or device OEM and asking this question directly. Please post a response here if you receive one.   >maybe because MediaTek gives out phase measurements, smartphones with it show in the program ( https://play.google.com/store/apps/details?id=com.chartcross.gpstest&hl=ru ) an accuracy of 1 meter?   This value is just an estimated accuracy computed by the chipset and doesn't necessarily represent better real-world accuracy. See https://barbeau.medium.com/measuring-gnss-accuracy-on-android-devices-6824492a1389 .   On Tue, Sep 24, 2024 at 12:09 PM Костя Стаханов <k.stah...@gmail.com> wrote:

Костя Стаханов <k.stah...@gmail.com>: Sep 24 07:37PM +0300 They (the manufacturers) will not answer me. Maybe some journalist or organization, but not a private person. I know that the accuracy value there is very approximate, but Qualcomm in the same conditions shows 3-5 meters. С уважением ,Константин С.

Sean Barbeau (xWF) <barb...@xwf.google.com>: Sep 24 12:59PM -0400 Related - a new version of GnssLogger is rolling out now (v3.1.x) that includes a Measurements tab:   https://play.google.com/store/apps/details?id=com.google.android.apps.location.gps.gnsslogger   On this screen you can see the "# usable ADR" signals. On devices that don't support ADR/Carrier Phase this value will be 0.   [image: image.png]   Sean   On Tue, Sep 24, 2024 at 12:38 PM Костя Стаханов <k.stah...@gmail.com> wrote:

Back to top

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to gpstest_andro...@googlegroups.com.

[Sean Barbeau]

Yes, GnssLogger is one thing I've been working on at Google. 😄

Sean

--
You received this message because you are subscribed to the Google Groups "GPSTest" group.
To unsubscribe from this group and stop receiving emails from it, send an email to gpstest_andro...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/gpstest_android/CAJiis_oHDiZFgVRdsyRs%2B5JanSgf4S0upfoaysgpm49aNzQXiw%40mail.gmail.com.

[Костя Стаханов]

I thought so! Excellent application and personally yours and gnsslogger! Thank you from the bottom of my heart and new successes in the matter of determining the location! Still, it is very interesting to know - why MediaTek gives out Phase measurements, but Quallcomm - no... can you tell us your assumptions?? I think I'm not the only one interested in this... Best regards, Kostya

С уважением, Константин С

ср, 25 сент. 2024 г., 16:40 Sean Barbeau <sjba...@gmail.com>:

[Sean Barbeau]

>I thought so! Excellent application and personally yours and gnsslogger! 

Thanks!!

>Still, it is very interesting to know - why MediaTek gives out Phase measurements, but Quallcomm - no... can you tell us your assumptions??

I can't comment on this because I have non-public information.

I would encourage everyone interested in phase measurements for devices with Qualcomm chipsets to let the OEM and Qualcomm know that you want this feature. Even if they don't reply, it's important that the they know there is demand for it.

Sean

[Kimo Crossman]

Can you recommend a way to contact the right Qualcomm staff? 

To view this discussion on the web visit https://groups.google.com/d/msgid/gpstest_android/CAEkVq%2BiTfuUZpP2bbRVqLU2ssr_RO8ao7rdG_6ch%2B2Zcg7pknQ%40mail.gmail.com.

[Валерий Заподовников]

So your team implemented the new network vs. GNSS time spoof check? 

Can I ask questions? Is network time NITZ or NTP or system time?

Do you use other GNSS besides GPS for time derivation? GLONASS has a little different (not UTC) time, while GPS is just off-by 18 seconds.

Finally, are you aware that adb.exe shell dumpsys time_detector

can be used to see what was used to sync time in Android 14 and I was talking to one of google people and they are still testing that feature where GNSS is used to sync time (Gnss suggestion history), makes no sense.

[Sean Barbeau]

Yes, I implemented the network vs. GNSS time spoof check. NTP time from an NTP server is used along with Location.getTime() (https://developer.android.com/reference/android/location/Location#getTime()) for the GPS_PROVIDER, which is the time from all observed GNSS satellites converted to UTC time so it's directly comparable to NTP time (it's GNSS chipset time for the computed location).

No, I haven't used adb.exe shell dumpsys time_detector myself.

Sean