[aprssig] Balloons again

[Russ Chadwick]

Another approach to avoiding the problem Al describes below is to use a 
communication channel other than the 144.390 MHz APRS channel. In 
addition to not overloading the existing APRS channel, this also has the 
advantage of avoiding the packet delays that are often present in the 
144.390 MHz APRS channel.  These types of delays are shown in this 
PowerPoint (0.5MB),

http://www.wxqa.com/packet_delays_144390.pptx

where the cases that have a callsign use the 144.390 MHz APRS channel 
and have many delayed packets (nearly half in some of the cases).  The 
two cases, AIRCOR-1 and AIRCOR-11, use the SBD Iridium channel and the 
two cases, EOSS-168 and EOSS-169, use 144.340 MHz while EOSS-170 uses 
147.420 MHz.  The I-gates used for these last three are listed about 2/3 
of the way down here here,

http://www.eoss.org/ansrecap/ar_200/recap168_169_170.htm

Our EOSS balloon experience has shown that it is much better to organize 
a set of trusted I-gates on another channel besides 144.390 MHz.

Russ
KB0TVJ



On 7:59 PM, Al Wolfe wrote:
>    Once again we have balloonist with apparently no idea of how to set 
> their path. Tuesday the Purdue effort with KC9UKT-5 and KC9USY-11 were 
> aloft with paths of Wide1-1. While I applaud these folks for their 
> efforts, I think a more beneign path of Wide2-1 would be much more 
> appropriate. (For that matter once these balloons reach 1k feet they 
> probably don't need any path.)
>
>    I appreciate their efforts and benefits of the package being 
> trackable, and their desire to recover their assets. But somehow 
> lighting up every properly configured base station for 400 miles twice 
> minute doesn't seem like the right way to do it. Maybe if the chase 
> vehicles were set to temporarily digi Wide2 it would help.
>
>    Of course, probably the best option would be to turn off or 
> minimize any paths above say 5k feet. A simple aneroid device could 
> switch the TNC. Or it could be done with a PIC looking at GPS altitude 
> data. At low altitudes the chasers need all the help they can get, so 
> a 30 second rep rate and Wide1-x would be quite useful. (Hint: An 
> acoustical beeping device like the old Sonalerts hung on the flight 
> string has aided many package searches.)
>
> 73,
> Al, K9SI
>
>