APRS
Automated Packet Reporting System

Automatic Position Reporting System (APRS) is a packet radio system used for tracking objects, people, vehicles, boats, aircraft, manned/unmanned balloons, weather systems, etc. APRS uses an Amateur Radio mode called unconnected (UI) packets. APRS was developed by Bob Bruninga WB4APR, and was first introduced to the Amateur Radio Community at the ARRL Computer Networking Conference in New Jersey in 1992.

Over the past years APRS usage has grown and expanded across the globe. Many new features and capabilities have been added since its inception. Worldwide, there are over 4000 stations on the map at any one time. There are a number of software programs that can be used to identify and track APRS stations (beacons). Basically, APRS is a packet system with the addition of a GPS (global positioning system) receiver. Many TNC's have GPS receiver inputs. There are stand alone GPS devices, which have map displays and tracker GPS units, which do not have map displays and are less expensive. GPS coordinates can also be manually entered into an APRS system. This is often done with fixed station operation.  Weather stations can be interfaced with APRS to report live and up to date weather information over an APRS network.

There are several vhf radios and handi talkies that have built in TNC's and GPS receiver inputs. These type of radios allow you to automatically transmit an APRS beacon and use voice mode without changing any settings. The universal frequency used for APRS is 144.390 MHz.

During emergencies, APRS can be very valuable. It can be monitored at an emergency operations center to track emergency response teams, mobiles, etc. Responders in the field can also see their own location. The Global Positioning System is maintained by the U.S. Department of Defense and consists of 25 satellites in orbit around the earth. Positioning information is determined by a small receiver which measures the time in micro-seconds that it takes to receive the broadcast from between 1-12 satellites. By receiving the signal from at least four satellites, position information down to about 10 meters can be determined. Altitude information can also be obtained from the system. In mobile situations you can determine speed and direction.

NCARES maintains an APRS Digi/IGate (W4NAS) on the air that covers Nassau County and local surrounding areas.
It is co-located with the W4NAS 147.000 repeater at the Callahan landfill.