[aprssig] APRStt for SAR usage?

[Robert Bruninga]

Had a SAR team get really excited about APRStt at Dayton.

They report position in UTM using 6 digits.  This is perfect for
APRStt for teams that do not have a tracker.  In this guy's
case, they have only a few ruggidized APRS trackers, and if some
teams could simply report their position by DTMF, then they can
give the trackers to those teams that can't read the map, and
the experienced teams can simply report by the 6 digits DTMF
using ANY radio with a key pad.

Anyone who has ever heard me talk about APRS, has heard me joke
that the only need for GPS in APRS is for those stations that
are LOST, MOVING, or cannot read a map.  Fortunately, all SAR
teams are very good at maps.

And if the teams used TACTICAL CALLS that were digits, then the
CALLSIGN DTMF string would be very short.  Instead of

 A9A2B42A7A7C37#   Station WB4APR with overlay "7"
 A10337#           Station "103" with overlay "3"

(Remember that APRS callsigns cannot be shorter than 3 bytes).

And since all SAR teams always carry the map with them, then the
GRID conversion to LAT/LON is easy to do in the APRStt gateway
software.

Bob, WB4APR