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[aprssig] APRS System Overiding Fundamentals

Robert Bruninga bruninga at usna.edu
Tue Mar 8 16:59:38 UTC 2005


In retrospect, I think some of the differences of opinion in 
some matters can be traced to some basic missunderstandings
of what APRS actually is and how it is being used...

In a nutshell, visualize the intent of APRS design as this:

APRS was designed simply to bring technology to the large
map display that is usually involved in every emergency 
headquarters or command post.  To place that ONE
MASTER VIEW in the hands of everyone involved
in the event or communications and to allow everyone
to help update it.

This way, anyone with fresh information can stick it on 
the map just like they used stick-pins and labels.  And this
new information propogates nearly instantly to everyone
everywhere.  Again, APRS is a view in virtual space
that everyone can see, and anyone can update by
simply moving an object or station on their screens and 
everyone else will see it.

This was the concept of APRS even before GPS became
affordable for trackers.  The availabliity of GPS simply made
it easier to track high priority moving assets that were so 
equipped, but the assumption all along was  that EVERY 
ASSET or "thing" or VIP or "happening" was on the map and 
being updated and moved throughtout the event so that the
virtual map had an up-to-date view of *everything* involved-in
or that had an impact on the operations. 

The firedept liason maintained the location of fires and its 
trucks the Police liason kept the locations of traffic probllems 
and accidents updated, the shelters liason kept the map 
updated with the needs and loading of the shelters, etc...  
A weather guy maybe kept the WX picture updated.  The 
power company liason keep the map updated with the 
locations of downed power lines and line crews.  ANd also 
areas without power... etc...  In other words,  EVERY COMMS 
liason person had an APRS display infront of him and focused 
on keeping his assets and objects and bulletins updated 
and that way EVERYONE had access to everything that was 
going on.

In the same vein, that is why there is the "overlay" file for 
events. The "overlay" for an event is for placing the never-
will-move assets and labels on everyone's maps at the 
begninning so that these non moving items do not take up 
any air-time.  Such as the locations of checkpoints or milemarks 
or checkpoints.

I fear too many people these days only view APRS as a
vehicle tracking system and not much else.  And since they
usually cannot get together enough trackers to track
even the most important assets, they dont even think about
using APRS as their "information management tool" which
it was designed to be.  Thus HAM radio in most cases
ignores APRS as a high-tech-more-toys side show instead
of a real EVENT tool (independent of GPS)...

Similarly the BULLETIN and ANNOUNCEMENT page was
also ment to be a "single virtual" bulletin board of fixed
size that containted the latest and most important items
of general interest to everyone.  Anyone could post or
update the bulletin board, and when it got too full or
when old bulletins were obsolete, they were removed.
Again, evryone was looking at the same virtual bulletin 
board.   (and responsible for the information there).

Problem was that some programs did not impltement 
it as this single restricted one-size virtual bulletin board 
which forced discipline on the users to post, and maintain 
their postings and update them.  Some  programs simply 
keep a runnning log of all bulletins and  announcements 
with no beginning and no end and no concept of a 
"common view of currently active" bulletins and 
announcemnets.  Hence they also do not provide for the
line-by-line editing, updating or replacement of individual
lines on that single event-wide virtual BULLETINS display.

So, I hope this helps everyone see the perspective from
which APRS was developed and what its primary applicaiton
was intended to be.  This might give some insight into 
where some comments are coming from.

SUMMARY:  In summary, I am frustrated that APRS these
days is beoming too much of a GPS toy and is actually being 
used less and less as an information management, 
communications and  display tool for events and operations.

Case-in-point was this weekends local Marathon. No one
even thinks of APRS in our club for this application, beacuse 
everyone only sees APRS as a map for tracking GPS.
Yet, 10 years ago  we used to do this marathon with APRS 
with *no* trackers at all!  And we kept track of the lead 
runner, lead woman, lead pack, the main pack, the guy
with the red hat, and the tail-bike and anyone else along 
the route of interest.  Operators at every laptop at every
station could see it all.  The police liason could see it, for
managing traffic,  the Run officials could see it for managing
their logistics, etc..

But now, nothing.  The current perception that APRS is 
just for tracking GPS trackers (which can never have
enough to fully do any event) is killing the use of this 
powerful tool in many areas... and many HAM radio
support applications.

Bob, WB4APR





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