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New Contributor
Posts: 5
Registered: ‎07-19-2012
My Device: Bold 9780
My Carrier: Drei AT

QGeoSatelliteInfo how to distinguish between GPS and GLONASS satellites

Hello,

 

I am interesting in obtaining details about visible satellite constallation.

I have found the class QGeoSatelliteInfo which should provide me some useful information like

- azimuth and elevation of SV

- carrier-to-noise ratio

- PRN (Pseudo-Random Noise code) number for satellite

 

One thing I can not understand is how to distinguish between GPS and GLONASS satellites (according to specs Z30 should support GLONASS)? Theoretically GLONASS SV can have PRN 1-24, GPS 1-36.

 

And some more questions to BB gurus:

- Does BB 10 devices support SBAS (EGNOS, WAAS etc.)? This SVs should have PRNs  of 120-160?

- What practically means A-GPS in BB 10 specs? I mean which types of  assistance information can utilise the device?

- Is this possible to get raw SV measurements (pseudoranges, phase, doppler shift)? If not, are any plans to implement such possibility?

 

Thanks in advance!

 

Retired
Posts: 68
Registered: ‎10-15-2012
My Device: Z10
My Carrier: Telus

Re: QGeoSatelliteInfo how to distinguish between GPS and GLONASS satellites

[ Edited ]

Hi,

 

From what we have gathered there is an NMEA convention for numbering satellites. The full GLONASS constellation has 24 slots, and the PRN range is 65-88. However 89-96 are available if more slots are allocated to on-orbit spares. I can't find anything official, just references (http://www.gps-forums.net/etrex-30-gps-glonass-t43512.html). As we understand it 

 

  • GPS has PRNs 1-32,
  • WAAS has PRNs 33-64, and
  • GLONASS has PRNs 65-96.

 

Qt5 QtLocation introduces a SatelliteSystem member to the QGeoSatelliteInfo class to facilitate this determination.

 

 

BB10 devices so far only recognize and use GPS and GLONASS satellites.

 

You can actually get access to more raw satellite data via QGeoPositionInfoSource (see the section on replyDat), but perhaps not exactly what you're looking for. Note that what is available via replyDat is subject to change.

 

I or someone else will try to get back to you re your other questions.

 

Regards,

Jim

 

New Contributor
Posts: 5
Registered: ‎07-19-2012
My Device: Bold 9780
My Carrier: Drei AT

Re: QGeoSatelliteInfo how to distinguish between GPS and GLONASS satellites

thanks! With PRNs everything is clear now. about replyDat property it is not really good described, I can see some examples, like getting HDOP (which is also interesting for me), but it is not clear what else can be accessed.... Question about raw measurements is still open. It is not clear for me general situation about this, for example, can be such information collected from navigation chip? If yes, than it is question to BB, if no, than It is question to Qualcomm.
Retired
Posts: 68
Registered: ‎10-15-2012
My Device: Z10
My Carrier: Telus

Re: QGeoSatelliteInfo how to distinguish between GPS and GLONASS satellites

Hi,

 

The replyDat property is purposefully vague, it may not have been a good idea to expose it in the public API. It is there and I mentioned it because if you traverse the QVariantMap you get an idea of what data we do collect at a lower level.

 

We have talked about supporting pseudo ranges but there are no official plans. Regardng AGPS, what we support is automatic and can't be affected by the user. The GPS fix will be computed asap with any assistance data available at the time (MSB, MSA). We don't allow the user to push assistance data.

 

I'm not sure what information can be collected from the gps chip. In any case this is probably a question for Qualcomm.

 

Regards,

Jim