APRS Automatic Position Reporting System By Nicolas - M1HOG

Introduction Disclaimer - Nothing in the talk is warranted as accurate, optimal or indeed sensible. Objective – An introduction to APRS and what it can be used for. Practical - High level talk and equipment walkthrough.

What is APRS Back a step to Packet Radio Developed in the early 80’s Small packets of data are transported over the AX.25 protocol using 1200 baud Bell 202 audio frequency-shift keying(AFSK) on a 2 meter FM FrequencyAX.25Bell 202audio frequency-shift keying KA9Q - Developed software for an early TNC – Terminal Node controller – Basically a Modem that uses radio instead of a phone line. KA9Q software was later modified to provide a TCP/IP stack and use a phone line modem. This enabled early IBM PC’s to access the Internet and was how first accessed the Internet.

APRS Overview Automatic Position Reporting System Invented and trademarked by Bob Bruninga WB4APR Developed in the late 1980's for local tactical digital communications, situational awareness and two way information exchange. - Phew Automatically sends data packets over the air for direct and indirect reception by other

APRS Overview Exchange information with other APRS equipped stations Call sign GPS Position (Altitude / Speed) Status Messages Comments Show Who / What is nearby – Stations repeaters etc. Send Send Messages and Bulletins via APRS network Receive Weather Reports Produce Maps showing objects and messages, so everyone sees the same

APRS 2 meter FM Radio TNC – Radio Modem – PC required GPS Tracker/TNC – No PC required Digipeater IGate

Radio 2 meter FM Radio Ideally with fixed low level audio input and output for easy interfacing to a TNC Most 2 meter FM radios can be easily adapted

Terminal Node Controller Terminal Node Controller - “Radio Modem” Traditional TNC Tiny Track (TNC) Open Tracker etc (TNC) Requires a PC Radios with built in TNC Kenwood D7 Kenwood D700 Yaesu VX-8RA

GPS Global Positioning System Position, speed and altitude Typically connected to via a serial lead to a Tracker…

Tracker TNC vs Tracker Functions as a “Smart” TNC Generates the contents of packets Typically - GPS plot, Call sign, Messages With out requiring a PC and separate TNC Tiny Track (TNC) Open tracker etc (TNC) May include a display to show packets received May have various other functions including..

Digipeaters A "digipeater" from "digital repeater", digipeaters receive a packet radio transmission (APRS packet) briefly store it and then retransmit it on the same frequency. Like voice repeaters, digipeaters are used to increase the distance a radio packet can travel Typically digipeaters enable packets to reach…

IGate Sends packets to APRS-IS (Automatic Packet Reporting System-Internet Service) Radio -> TNC -> PC -> Internet connection PC Software - APRS4R many others are available The APRS data is then be plotted on to maps by various internet sites…

APRS.FI - M3NQG IGATE

Recent Tracks

G0LGJ

G0LGJ -> M3NQG

M3NQG - Stations Heard

Equipment Walkthrough Kenwood HT – Tiny Trak - GPS Dave G4ETG – Kenwood 700

Links APRS - Tiny Trak - Open Tracker Kenwood TH-D7 - thd7ae.html thd7ae.html Kenwood D tm_d700ae.html tm_d700ae.html APRS.FI -

Thank you ! This presentation is available at Nicolas