jks

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jks
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  • GPS Admin screen

    jksjks
    The GPS time displayed is the time computed when the last position solution was calculated. This can be arbitrarily delayed for a bunch of reasons. Maybe I should call it something else.

    First of all GPS time is offset from UTC by, what, 17 to 20 seconds now because of UTC leap second adjustments? So keep that in mind.

    Second, the GPS code I use, which is from Andrew Holme's wonderful Homemade GPS Receiver project (http://www.holmea.demon.co.uk/GPS/Main.htm), while excellent is not as sophisticated as what you'll find in a cellphone or modern GPS receiver. The maximum rate at which solutions are calculated is every 4 seconds under the best conditions. Not 10 times a second +/- like most GPSs. Modern GPSs also have better software & firmware algorithms that do better tracking and thus have better sensitivity. That's why they perform better even though we use the same front-end chip (and if you factor out the antenna differences).

    The GPS process of searching (acquiring) new satellites is stopped when there are active SDR connections on the Kiwi. Existing sats will continue to be tracked (and timing solutions calculated) until they eventually drift out-of-range. This is because the acquisition process uses an expensive FFT which cannot run simultaneously when there are multiple SDR connections. The Beagle doesn't have enough CPU to do all this work and still meet the realtime deadlines.

    So all these reasons are why the displayed GPS time will lag UTC, sometimes significantly. The GPS isn't used for anything except calibrating the ADC clock. And for that the timeliness of the GPS time measurement doesn't matter (only the difference between the last two GPS time calculations is used). Things like WSPR time presume accurate time is being received over the network (Internet) via NTP.

     
    M0TAZ

  • new WSPR decoder in release v1.54

    jksjks
    Okay, I see now what the problem is. The callsign hash table used for the new type 2 and 3 messages is allocated in an unfortunate way for the limited physical memory (500 MB) of the Beagle. I'll release a fix for that today. Until then please only run one instance of the decoder to keep it from crashing.

    WA2ZKD

  • Local Timeout

    jksjks
    For the next release I've changed it to ignore the inactivity timeout for local network connections.

    Ignoring it for password-required connections is a little more complicated because you can imagine people wanting that behavior to be configurable.

    WA2ZKD

  • release v1.45: improvements to WSPR and no more upload to wsprnet.org?

    jksjks
    That's probably more of a question for the official WSPR group: http://wsprnet.org/drupal/
    My impression is that they take all loggings seriously and some people even do analysis on the database (which goes back to 2008!)

    There is an open feature request to allow the WSPR extension to be started automatically and run unattended (no browser connection necessary) which is in the spirit of collecting lots of spots.

    WA2ZKD