Galileo problem [fixed in v1.640]

edited December 2023 in Problems Now Fixed

I don't seem to be getting a stable acquisition, when I only select to use the Galileo satellites in the GPS tab (QZSS/Navstar deselected).

For example, it shows tracking 6 and good 6 satellites for a few seconds, and then for a few seconds only 2 good satellites. This cycle is repeating forever.

During the few seconds while it shows only 2 good satellites, it seems to be losing the lock and it tries to acquire new satellites.

Can someone reproduce this?

Comments

  • edited November 2023

    Can someone reproduce this?

    I can't. If I try the same as you did, it starts with the number of green bars slowly increasing up to 6, which takes some time. After that, it seems to remain stable at 6 satellites; no "cycling" as you described. The shown map position is as it should.

    (Kiwi ver. 1.636 with Debian 8)

    73,

    Manfred

  • edited November 2023

    Ok that's interesting. It happens on all 3 of my kiwis, but they run debian 10.13.

    The "good" count even drops to zero from time to time.


  • I am seeing this now. I get 4 green S (solution) status flashes in a row followed by 4 periods of no S. Sometime a P (parity error) during those times. My guess is that this is a problem in the message extraction code for Galileo, which is completely different from Navstar/QZSS.

    I haven't looked at that code in years. It will take some time to debug. Especially with so much else going on..

  • Glad it's not just me, thanks for checking.

  • Okay, this turned out to be a simpler problem than I thought and is fixed in today's v1.640 release.

    The code was incorrectly flagging unused Galileo subframe types as errors (e.g. the almanac subframes). You should no longer see the green S indicator drop-out in a regular, repeating pattern for the sats with PRNs of Enn (and the P [parity error] indicator light up during the drop-out).

    You'll still see occasional cases where a solution will exclude some or all of the Galileo sats. Same for the Navstar or QZSS sats. But this is a normal part of the solution processing.

  • Thank you!

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