About APRS

APRS (Amateur radio Position Reporting System) is a simple tool that lets people track the position of any amateur radio operator (ham) who has the hardware to make his position known.

In his vehicle, the ham has a transmitter, a GPS receiver and a small computer that sorts out the time and position and generates a coded signal to feed into the transmitter, which then sends it off to a receiving site.  The transmissions can occur at regular time intervals such as once every 20 to 30 minutes or when the position changes or the direction of travel changes by so many degrees.  A stationary unit won't be transmitting much, but a mobile one can send a brief signal every few minutes or so.

Our unit is a simple box about the size of a pack of cigarettes, with connectors for a transmit antenna, the GPS receiver and power.  Both the antenna and the GPS receiver magnetically mount on the roof of the vehicle.

Up and down the country, other hams have set up receiving stations on the APRS frequency.  These are unattended receivers on a fixed channel.  When a signal is heard, a small computer decodes it and sends the information over the internet to a database in Finland.  I guess it's there in Finland because the guy who started this off probably came from that country.

Anyone who wants to track the ham concerned simply goes to the web address https://aprs.fi   That web site will pop up a Google Maps view and a box on the right side for entering data.

If you enter zl1lc-9 in the top Search box and click on Search, it will report our last known position.  If you then go below and set the Show last box to 24 hours, and the Track tail length to 24 hours, you will see our path over the last 24 hours.  The database holds information for several years.

Below is a screen shot of a ham using his id of zl1nl-8.  Each one of those dots in his trail has information as to which site picked his signal up, the time and the speed of his vessel.

So enter zl1lc-9 into the box and sit back and see where we have been.

Sometimes the reporting is spasmodic because our transmitter power is only 10 watts and in many places of NZ, there are not hams about with receivers set up for APRS or there are lots of hills in the way between our vehicle and their receiving site.  But persist and you should be able to track us up the two islands.