but isn't 99.9% of all APRS broadcasting? You never really expect a response from anyone... Most of it is amateurs BROADCASTING their locations, no emergency traffic...
That is simply because too many people were completely mislead into thinking of APRS as a vehicle tracking system which is just wrong. It was nothing of the kind. It evolved from the 1980's desire to get away from one-on-one packet BBS's with NO human contact back to HUMAN-to-HUMAN live information exchange.
But then in the mid 1990's GPS came out and so did a lot of stupid trackers and now we are stuck with this light's-on-nobody-home scenario in a lot of people's minds. See how wrong these assumptions are: http://aprs.org/APRS-tactical.html
My focus in APRS has always been about live contact. That is why now all new APRS radios not only communicate the position of the other stations, but also their voice contact frequency in every packet. See: http://aprs.org/localinfo.html
Bob, Wb4APR