APRS Automatic Position Reporting System

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APRSAutomatic Position Reporting System

• By Nicolas - M1HOG
• www.M1HOG.com

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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.

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What is APRS

• Back a step to Packet Radio
• Developed in the early 80s
• 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
  Frequency
• 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 PCs to access the Internet and
  was how first accessed the Internet.

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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

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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 Email
• Send Messages and Bulletins via APRS network
• Receive Weather Reports
• Produce Maps showing objects and messages, so
  everyone sees the same

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APRS

• 2 meter FM Radio - 144.800
• TNC Radio Modem PC required
• GPS
• Tracker/TNC No PC required
• Digipeater
• IGate

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Radio

• 2 meter FM Radio - 144.800
• Ideally with fixed low level audio input and
  output for easy interfacing to a TNC
• Most 2 meter FM radios can be easily adapted

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Terminal Node Controller

• Terminal Node Controller - Radio
  ModemTraditional TNC
• Tiny Track (TNC)
• Open Tracker etc (TNC)
• Requires a PCRadios with built in TNC
• Kenwood D7
• Kenwood D700
• Yaesu VX-8RA

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GPS

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

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Tracker

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

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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

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IGate

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

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APRS.FI - M3NQG IGATE
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Recent Tracks
15
G0LGJ
16
G0LGJ -gt M3NQG
17
M3NQG - Stations Heard
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M3NQG - Stations Heard
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Equipment Walkthrough

• Kenwood HT Tiny Trak - GPS
• Dave G4ETG Kenwood 700

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Links

• APRS - http//www.aprs.org/
• Tiny Trak - http//www.byonics.com/tinytrak/
• Open Tracker -http//www.argentdata.com/products/o
  tplus.html
• Kenwood TH-D7 - http//www.kenwood.com/i/products/
  info/amateur/thd7ae.html
• Kenwood D700 - http//www.kenwood.com/i/products/i
  nfo/amateur/tm_d700ae.html
• APRS.FI - http//aprs.fi/

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Thank you !

• This presentation is available at
• www.SADARS.org
• Nicolas
• www.M1HOG.com