APRS

From Megawiki

Automatic Position Reporting System (APRS) is an amateur radio based automatic position reporting system for tracking and digital communications, and was developed by Bob Bruninga, callsign WB4APR, at the United States Naval Academy.

Capabilities

In its simplest implementation, APRS is used to transmit real-time reports of the exact location of a person or object via a data signal sent over amateur radio frequencies. In addition to real-time position reporting capabilities using the Global Positioning System, APRS is also capable of transmitting a wide variety of data, including weather reports, short text messages, radio direction finding bearings, telemetry data, and storm forecasts. Once transmitted, these reports can be combined with a computer and mapping software to show the transmitted data superimposed with great precision upon a map display.

Technical Information

In its most widely used form, APRS is transported over the AX.25 protocol using 1200 baud Bell 202 audio frequency-shift keying on frequencies located within the amateur 2-meter band - usually 144.390 MHz in North America, 145.175 MHz in Australia, 144.575 MHz in New Zealand, 144.930 MHz in Argentina and 144.80 MHz throughout Europe. An extensive digital repeater, or "digipeater" network provides transport for APRS packets on these frequencies. Internet gateway stations (i-Gates) connect the on-air APRS network to the APRS Internet System (APRS-IS), which serves as a worldwide, high-bandwidth backbone for APRS data. Stations can tap into this stream directly, and a number of databases connected to the APRS-IS allow web-based access to the data as well as more advanced data mining capabilities. A number of low-earth orbiting satellites and the International Space Station are capable of relaying APRS data.