[aprssig] APRStt for SAR usage?

[Bob Bruninga]

> When I first read your web page 
> a few days ago I thought this [SAR]
> was an excellent use of APRtt.  We 
> use MGRS [in Canada] which is usually 
> a 8 digit string and we do use 
> numeric Team numbers

Peter,

Would you consider helping to write a users guide for your application?  It would read better if it was written by someone who does SAR routinely to make sure it had the right approach.

In other words, describe how you think the teams would be briefed to use this capability at a typical SAR event. For example, within the SCENE of the SAR, are all 8 digits really needed, or is maybe the most significant digit always the same within a given SAR field area?

My thoughts are that voice comms are very important, and so we might not want to do the DTMF on the voice channel.  The idea would be to put the APRStt input channel in the CALL channel of all HT's.  To make a DTMF report, the team momentarily QSY's to the CALL (APRStt channel) listens for 3 seconds (to make sure it is not in use) and then sends his report, and listens for the "R" in CW, or Voice ack and then returns to his assigned voice channel?

>On 17-May-09, at 1:48 AM, Robert Bruninga wrote:
>
>> 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 a 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# Stn WB4APR with overlay "7"
>> A10337#         Stn "103" with overlay "3"
>>
>> (Remember, APRS calls cannot be shorter than 3 bytes).