Kenwood TM-D710GE - Manual (Page 6)

01 APRS Operations (Written by Bob Bruninga, WB4APR)
2
APRS Overview
History
APRS was developed beginning back in the 1980s by Bob Bruninga, WB4APR, as a real‑time local tactical
communications system for rapidly exchanging digital data of immediate value to local operations. This really took off
when GPS became available and MAPS were integrated into the system for tactical situational awareness of everything
in the net. Unfortunately, in the 13 years since GPS became readily available to most operators and was added to
APRS to facilitate the display of the local network, too many follow‑on applications have focused too heavily on the
vehicle tracking function at the expense of many of the more valuable functions of APRS for human‑to‑human ham radio
information exchange in real time.
As a result, too many operators appear to misunderstand some of the basic tenets of APRS. APRS is not a vehicle
tracking system. The Automatic Packet Reporting system is simply a local data channel designed to share everything
that is going on in ham radio in real time. This channel 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 1980s, was to provide
a single information resource channel where everything happening could be beaconed and where anyone could monitor
to find out what was going on across all aspects of ham radio interests.
Local Information Exchange
A fundamental principal was 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 new information was rapidly disseminated but 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 would still see the same consistent information
displayed in a consistent manner (independent of the particular display or mapping system in use).
To emphasize the freshness and importance of local information over the sometimes interference of older and more
distant data, the TM‑D710 implements both the decay algorithm and also the new proportional pathing algorithms.
THE GOAL IS COMMUNICATIONS and LOCAL INFO UPDATE, -NOT- JUST VEHICLE TRACKING!
Mobile Information Resource
APRS was never intended to be just a vehicle tracking system (GPS was added in the 1992 time frame when GPS
became affordable). APRS is much more. See the KENWOOD mobile display below. This is the STATION LIST which
shows the nearest 100 stations heard. In this case, not only are the two stations of AB9FX nearby, but also his current
voice operating frequency is visible. Also, we can see that this transceiver is in operating range of three voice repeaters
that are also identifying themselves as objects on APRS as the locally recommended voice operating channels.
Fig. 1-1 TM‑D710 Front Panel showing Station List