[aprssig] RE: APRS System Overiding Fundamentals

Phillip B. Pacier ad6nh at arrl.net
Tue Mar 8 23:45:47 CST 2005

Thanks, Dick.

Baker to Vegas is a law-enforcement team relay race that tracks 120 
miles through the Mojave Desert, roughly from the town of Baker, CA to 
Las Vegas, NV.  There will be a total of 230 teams running in the event 
this year.  That is 5,750 total runners, plus support, volunteers, and 
spectators, so we figure we probably bring a good 10,000 people out into 
the desert for a weekend.  It is one of the larger amateur radio 
supported events, with about 250 hams working race communications and at 
least an equal number assisting individual teams with their inter-team 
communications.  500 hams!  Wowzers!

APRS began to become popular with the race several years ago.  Last 
year, we had 45 of the follow and support vehicles with full tracker 
packages.  We certainly make excellent use of that facet of APRS.  This 
year, it should be around 50.  We have had to come up with some 
ingeneous ways to acommodate 50 trackers on the 1200 baud channel, but 
it works fairly well with a minimal amount of impact to the surrounding 
areas (this year should be very little impact, as we will be using our 
own race-specific unproto path).  Many of the teams and support crews 
monitor the action on RF receiver/laptop setups or from internet 
terminals via the www.b2vtracking.com website.

This year, I do intend to make use of objects to assist with the 
tracking of important vehicles, such as the medics and helicopters (45 
medics, 10 ambulances, and 2-3 birds are reserved for the race), and the 
first and last place runners (if they do not have tracking systems in 
their cars).  It will be a total use of many different parts of APRS.  
It is also painfully obvious that we need to setup infrastructure for a 
parallel channel next year, and that will be done.  Whether it will be a 
9600 baud trunk, node, or a parallel 1200 baud network is to be 
determined, but it will have to be done as we are already exceeding the 
channel capacity.  It works because all trackers use KPC3 TNCs that have 
their beacons time slotted.  Each beacon box sends out a beacon every 4 
minutes, and the slots are spaced 4 seconds apart.  This assures that no 
tracker box will transmit at the same time as another, and we generally 
have enough digis along the course that one or more can hear the 
tracker.  It isn't perfect, and it is tough for 144.39 to handle, but it 
will be this way for one more year.

If you have any other questions about the race or how you can become 
involved <g>, send me an email!

Back to you, Dick! :)

Phil - AD6NH
B2V APRS Coordinator

dick at kb7zva.com wrote:

>>So my present sermon is just about getting people to
>>use APRS displays even if they dont want to bother
>>with a GPS... 
>Great sermon. Also, I'm happy that Wes mentioned all the
>NWS stuff. Do I detect another sermon soon or something
>that has to do with more objects?
>A feature I like about Ui-View is that an object is not
>placed in the total stations list.
>Talk about events...
>Phil is working on the annual Baker 2 Vegas Race. That is
>not a small event. Maybe if Phil wants he would give us
>an over-view on how APRS is involved. Phil is the communications
>coordinator for the race.
>Dick, KB7ZVA
>aprssig mailing list
>aprssig at lists.tapr.org

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