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[aprssig] Final Web Page for AE0SS-11 and KC0YA-11 Balloon Launch Up -- APRS-IS Problems

Earl Needham earl.kd5xb at gmail.com
Sat Mar 12 20:03:46 UTC 2011


In the past, as I have driven east on I-76, I have noticed one digi out east
of Brush.  I'm not sure if there is an IGATE associated with it or not.
This particular digi has lat/long in the beacon, however it isn't formatted
APRS-style, thus ensuring it won't show up on APRS maps.  I kinda suspect
this digi to be the cause of at least some of these delays.

Vy 7 3
Earl
KD5XB


On Sat, Mar 12, 2011 at 12:41 PM, Stephen H. Smith <wa8lmf2 at aol.com> wrote:

>  The dual launch announced earlier is over.   The final summary page is
> now on my website at:
>
>     <http://wa8lmf.net/LiveTrack> <http://wa8lmf.net/LiveTrack>
>
> Major APRS-IS issues were evident
>
>  The actual downlink for APRS data from the balloons to the ground was on
> a private channel, that was then retransmitted on the usual 144.39 frequency
> to find it's way to igates and the APRS-IS (APRS Internet System).
>
> Tracking of these launches were marred by severely-delayed packets being
> injected into the APRS-IS.  This causes more recently reported data to be
> superseded by older data. The result is tracks that "hyper-jump"
> forward-backward-forward-backward.    In the case of  aerial vehicles like
> balloon, they also bounce up and down in  altitude.  (Note the "grass" of
> vertical jumps on the AE0SS-11 vertical profile graph, and the hiccups on
> both profiles.)
>
> Delays in passing packets from the TNC to the attached computer is a known
> bug in KPC3+ TNCs operated in KISS mode connected to a computer.  The
> problem appears randomly after several days or weeks of operation, and can
> be cleared by issuing the RESET command to the TNC or by cycling it's power
> OFF and then back ON.  This problem primarily affects home digi/igate
> stations, since they typically use a computer-based setup.   It does not
> affect KPC3+ TNCs operating in stand-alone mode, as would be the case with
> most remotely located digipeaters.
>
> Further,  these  launches were  marred by one or  more TNCs at digipeater
> or igate sites operating in PASSALL mode (a.k.a. "junque" mode). Numerous
> posits with impossible values were passed including elevations hundreds of
> feet  below sea level,   wild hyper-jumps 100s of miles at right-angles to
> the track path, and multiple corrupted versions of the two balloons'
> callsigns.
>
> The tracks were further confused by the balloon trackers apparently being
> powered up (for a test??) on the south side of the Denver metro area, before
> being taken to the launch site. Or were these posits sent before the GPS
> receivers achieved lock at the launch site?
>
>
>  ------------------------------
>
> --
>
> Stephen H. Smith    wa8lmf (at) aol.com
> EchoLink Node:      WA8LMF  or 14400    [Think bottom of the 2M band]
> Skype:        WA8LMF
> Home Page:          http://wa8lmf.net
>
> =====  Vista & Win7 Install Issues for UI-View and Precision Mapping =====
>     http://wa8lmf.net/aprs/UIview_Notes.htm#VistaWin7
>
> *** HF APRS over PSK63 ***
>    http://wa8lmf.net/APRS_PSK63/index.htm
>
> "APRS 101"  Explanation of APRS Path Selection & Digipeating
>   http://wa8lmf.net/DigiPaths
>
>
>
>
>
> _______________________________________________
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> aprssig at tapr.org
> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
>
>
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