[aprssig] APRSTT from GPS

[PE1RDW]

the discusion on the runner tracking has me wondering about a solution 
for a problem I'm facing.
Once a year my redcross section does support for a 80 km hike and up to 
now we depend on vocal relaying of location information, eg last hiker 
is at post 10, bus 2 left central post on route to post 5 etc. this is 
offcourse very basic and has a very low resolution, just have to guess 
how far between posts they are. We could use APRS but the red cross 
licence does not allow data communication only tone signaling like dtmf 
5tvo etc.

Would it be feasable to program a MPU to translate the NMEA input to a 
DTMF or 5tvo string and then back to a position instead of depending on 
manual input because the people opperating the mobiles will be copilots 
of the verhicles with no ham background and very limited radio skills 
(we're happy if they remember to stick to radio protocols), even our own 
trained redcross workers have proven time and time again that during 
action they do not haven time to report their position every few 
minutes, only when they need backup.

In all likelyhood only the 1/10ths and 1/100ths of a degree need to be 
transmitted with no more then 10 trackers so I estimate that 5 digits 
transmitted will be enough.

73 Andre PE1RDW