Automatic Position Reporting System
(APRS) is, as the name suggests, a reporting system for the current position. APRS systems send out short data packets with the position information in simplex. The data packets are spread according to a certain algorithm and are received and forwarded by the individual data stations
. The frequencies made available for the APRS system are at 144.800 MHz. The ARPS stations constantly transmit their current position, as well as weather data and other measured values, from which the receivers can display the location and movement of the station.