GLONASS Accuracy and 10Hz Variant

[Foxtrott]

I'm interested in comparing the accuracy difference between the default GPS
and the GLONASS output for my location, but in the end I would need to use a 10Hz variant.

Is the GLONASS example variant using only GLONASS satellites or is it combined with normal
GPS as well to increase the overall accuracy?

Additionally is it possible to modify the GLONASS variant to support 10Hz output, or is this
something which is currently planned to be released as an example package?

Regards

[U.Wilhelm]

We will prepare a 10Hz Version that support the GLONASS Mode.
A Software that use both System at the same time is not possible. The used GPS Receiver could only handle one system at a time.
As soon as we have tested the 10Hz GLONASS SW we will post the code here.

[U.Wilhelm]

Please find attached the code for using the unit with the GLONASS GPS with the max. update rate that the U-Block GPS could provide.

08_GLONASS_10Hz.zip

(155.21 KiB) Downloaded 22 times

After you have flashed the Device, place the Antenna outside of the builduíng and wait some minutes !
Check the ID 0x620 for Status and the ID 0x621 to 0x625 for Data

PCAN-GPS_GLONASS.JPG (55.61 KiB) Viewed 292 times

[Foxtrott]

Thank you very much for the quick support in providing an additional variant.
I will try and compare the accuracy performance between the two variants as
soon as possible then.

I'm actually located in Japan and I also noticed that the QZSS satellites are supported
by the MAX-7W. Is my understanding correct in that these satellites are received
combination with with GPS variant or is this also something which needs to be manually prepared?

Best regards

[U.Wilhelm]

The QZSS ist the same as the GPS. But as we wrote, if the QZSS/GPS is activ, the GLONASS will not work and vice versa.
(this is limited by the used u-blox modul type - other u-blox receivers could also handle both at the same time)

See document of the u-blox module we use ( MAX-7)

1.5.3 QZSS
The Quasi-Zenith Satellite System (QZSS) is a navigation satellite overlay system for the Pacific region covering Japan and Australia which transmits additional GPS L1C/A signals.
u-blox MAX-7 positioning modules are able to receive and to track these signals simultaneously with GPS, resulting in better availability, especially under bad signal conditions e.g. in urban canyons.

Inside the Data-Sheet you also find this information:

"QZSS and SBAS signals (by default) can be received concurrently with GPS signals."

So the QZSS is also used by default if you setup the unit to communicate with the US GPS. Simply use the GPS 10Hz sample Version as it is - it also wil use the QZSS System.

In the sample code that we post in ths thread for using the unit with GLONASS, you also find how to setup the unit to run with the QZSS.

Code: Select all

     pb_tx[26] = 0x05;    // GNSS identifier QZSS
     pb_tx[27] = 0x00;     // min channels
     pb_tx[28] = 0x03;     // max channels
     pb_tx[29] = 0x00;     // reserved
     pb_tx[30] = 0x00;     // disable QZSS

We are not bable to test it - we are placed in Germany - no chance to see any QZSS satelitte - sorry !
If ypou could verify it, a feedback will be perfect!