Argent Data Systems
11 |
Introduction to APRS
To understand the Tracker4 and how
it can be used, it is important to first
understand exactly what APRS is.
APRS stands for Automatic Packet
Reporting System. The name is a
trademark of its creator, Bob Bruninga,
WB4APR. What the name refers to can
be a subject of considerable confusion
to newcomers.
Primarily, APRS is a communications
protocol. It defines how data
(including station and map object
positions, weather information,
radio direction finding readings, text
messages, and telemetry) can be communicated among packet radio stations.
APRS can also refer to the network that carries this information. Throughout the United States,
Europe, and several other countries, a network of digital repeaters (‘digipeaters’), usually on
a common nationwide frequency, provides a transport for APRS packets. Most APRS stations
operate on one of these common channels, but not all.
The APRS Internet System (APRS-IS) is an Internet-based adjunct to the radio network. Internet
gateways (IGates), often simply home PCs with an Internet connection and a radio, pass traffic
from the radio network to a shared, worldwide APRS stream. Many IGates will pass at least text
message traffic, and sometimes other data, from the Internet back to the radio network. In this
way, text messages can be passed from one station to another even when a digipeater path
between the two doesn’t exist or isn’t reliable.
The name APRS is also sometimes used to refer to WB4APR’s original MS-DOS APRS mapping
program, but this is now properly called APRSdos. Numerous other mapping and messaging
