[aprssig] tactical call identifier packet

[Curt, WE7U]

On Wed, 23 Jul 2008, Robert Bruninga wrote:

> I am opposed for the simple reason that not everyone will ever
> get the translation packet, and not every system will use it.
> Thus, a large number of participants will see one thing, and
> another large number of people will see something totally
> diffferent.
>
> And such a situation is a built-in disaster for a communications
> system whos objective is for everyone to see the same thing!  If
> one wants a -thing- on APRS to have a certain name, then he
> needs to give that thing that name in the first place.

A wonderful idea but hard to implement in practice.

For instance a special event:  People show up with several types of
devices, some transmit-only, some two-way and/or message-capable.
Most of these didn't even go to the two sites where we were
operating the APRS mapping stations.  Some were late getting to the
event at all.  All were deployed/re-deployed via voice comms.  Bob &
I entered tactical callsigns on our local Xastir displays so that he
and I were in sync.

To have gotten these volunteers to change their configuration
before-hand to "SAG1", "SAG9", etc would have been a major obstacle
due to the varied types of equipment (and varied knowledge of the
users).  The attempt may have made some of them inoperable RIGHT
BEFORE WE NEEDED THEM!  Some of the operators may have balked at
people messing with their configs at all.

By leaving their configuration alone we up'ed our chances of having
more usable mobile stations available for the event.  We really
didn't care whether other hams could tell who "SAG1" was.

Also by leaving their configurations alone we didn't have to meet up
afterwards and try to revert to their former configurations.  The
people that showed up with working APRS mobiles, we used.  They were
assigned tactical calls quickly and easily without touching their
equipment.  Those that showed up w/o working equipment we didn't
mess with.  There's just not time for such things in those kinds of
events.

Tactical callsigns are the ultimate for come-as-you-are APRS.


> Now the compromise we ended up with is that if such a ALIAS
> packet were used, that on receipt the display *must* display
> both the original call and the ALIAS always.  One may be in
> Parenthesis to distinguish, but that way, the continuity across
> all platforms is maintained.

First I've heard of that (that I recall).  When a tactical call is
defined in Xastir we replace the callsign text with the tactical
text on the screen.  Adding more text can clutter up the screen
quite fast, not an advantage when you're tracking multiple objects
in a tense situation.  If I absolutely need to know a callsign I can
look it up with a mouse operation quickly.  Mostly callsigns would
be in the way.  In fact we have an option to show ONLY stations that
have tactical callsigns defined so that we can unclutter the display
for special events.  It's _very_ useful.

-- 
Curt, WE7U.				archer at eskimo dot com
http://www.eskimo.com/~archer
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