[aprssig] Curious about bogus packets on Findu

Lynn W. Deffenbaugh (Mr) ldeffenb at homeside.to
Thu Sep 30 12:39:49 EDT 2010

I'm just guessing here, but I suspect that those areas have a digi or 
IGate running in PASSALL mode that has the ability to corrupt single 
digits in an APRS packet.  aprs.fi has a sanity filter that removes 
"impossible" packets that appear to have traveled too fast, which is 
what these would look like.  If you pull up the raw packets (as many as 
might be available) in aprs.fi, are there any flagged that way?

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

Steve Noskowicz wrote:
> Returned from a week long Illinois-Colorado trip last night (15 hrs straight through and I can't figure out why I'm not one giant ache) (:-)
> For anyone wanting to look...or who cares.  It's no problem for me, just wondering.
> Noticed some error lat long locations on Findu's Long term tracking.   I've not seen this before.
> I save some of these images to show with my APRS talks.
> http://www.findu.com/cgi-bin/track.cgi?call=k9dci-9&start=400&geo=usa.geo
> The one in North Western Pa is early in the time period.
> The one in SE Wisconsin (and the one below the track in Illinois) is late in the trip and is probably a latitide-only glitch from one of the packets at the same longitude.  I figured this out by changing the findu &start time in Steve's URL.
> However, it is difficult for me to tell looking at the raw data just which packet it is.
> I also see some raw packets with the TOCALL (APK101) instead of the Mic-e data and don't know enough to understand that.
> I couldn't see these glitches on aprs.fi.
> --
>  73, Steve, K9DCI   USN (Vet) MOT (Ret) Ham (Yet)

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