OVERVIEW: The Automatic Packet Reporting System was designed to support rapid, reliable exchange of information for local, tactical real-time information, events or nets. The concept, which dates back to the mid 1980's, is that all relevant information is transmitted immediately to everyone in the net and every station captures that information for consistent and standard display to all participants. Information was refreshed redundantly but at a decaying rate so that old information was updated less frequently than new info. Since the primary objective is consistent exchange of information between everyone, APRS established standard formats not only for the transmission of POSITION, STATUS, MESSAGES, and QUERIES, it also establishes guidelines for display so that users of different systems will still see the same consistent information displayed in a consistent manner (independent of the particular display or maping system in use). See the original APRS.TXT. The two images below should give you an idea of the kinds of information available to the mobile operator on his APRS radio. On the left is the Kenwood D710 radio showing the station list, and on the right is the attached GPS with map display showing the location of other APRS stations.