HFEA Amateur Radio Club - K6QEH APRS - Automatic Position Reporting System Dennis Kidder WA6NIA 1 June 2001

11 April 2001APRS - Automatic Position Reporting System What is APRS? Automatic Position Reporting System –Developed (and trademarked) by Bob Bruninga WB4APR Based on AX.25 –Unnumbered Information packets (UI) –UI ‘s are unacknowledged VHF and HF mobile and fixed operation Uses GPS (mobile) or fixed coordinates Other terms: –Mic-E -- Mic Encoder, TNC-less encoding of location, course and speed –MIM - Micro Interface Module -- Telemetry TNC on a chip What started out in 1990 as a digital-equivalent of voice networks has evolved into the RF-equivalent of the Internet. Imagine being able to send a short message to anyone, anywhere, anytime.

11 April 2001APRS - Automatic Position Reporting System More about APRS Can be used to send simple text messages –May be directed to a specific address or “broadcast” –Text messages are acknowledged Beacon can contain other information: –Weather station –Station status text, e.g., address, QTH, etc. Protocol contains encoding for displayed icon Can filter on “groups” –use special, “designated” messages –limits what is displayed Applications: –Locating stations in disaster, public service events, etc. –Tracking moving stations –Simple messaging

11 April 2001APRS - Automatic Position Reporting System What is needed for APRS? Simple: just a computer with Internet connection More complex: –Hardware VHF -or- HF transceiver –antenna with vertical polarization APRS-ready TNC -or- Any APRS software-compatible TNC Computer if using APRS software Optional: NMEA-compatible GPS receiver –Software Depending on radio/TNC, possibly none -or- WinAPRS -or- MacAPRS APRS+ PocketAPRS for Palmtop computers

11 April 2001APRS - Automatic Position Reporting System Typical Hardware MFJ Data Radio and Kantronics KPC-3 TM-D700A TH-D7G Garmin GPS units StreetPilot GPSmap 162 eMap Kenwood

11 April 2001APRS - Automatic Position Reporting System GPS requirements What is NMEA? –National Maritime Electronics Association –Defines standardized protocol used by GPS receivers to send coordinates and receive waypoints TNC or computer receives coordinates from GPS receiver GPS map displays received stations –Received from TNC or computer as waypoints –Displays callsign of APRS station

11 April 2001APRS - Automatic Position Reporting System WinAPRS Screen Shots

11 April 2001APRS - Automatic Position Reporting System APRS+SA Screen Shots DeLorme Street Atlas Display Station List

11 April 2001APRS - Automatic Position Reporting System How is APRS distributed? For small groups, just point-to-point For larger areas, uses digital repeaters and routing protocols –Digital repeaters (digipeaters or digis) are wildcard named “RELAY” and “WIDE” RELAY can talk to WIDE or to any local WIDE talks to WIDE –Anyone can run RELAY –WIDEs tend to be fixed and well known. VHF-HF gateways Internet gateways –When configuring an APRS station for “packet path” Use “RELAY,WIDE,WIDE” or, Specific callsign of RELAY or WIDE station, if known

11 April 2001APRS - Automatic Position Reporting System Listing of raw packets from WA6NIA-14 Shows position info, repetitive message ( ) Shows two specific WIDE digis...K7GIL-1 and W6KRW-2 –Also shows the generic wildcard routes: RELAY and WIDE How is APRS distributed? WA6NIA-14>APD214,RELAY*,WIDE,WIDE:= N/ Wk191/000/Mic-E/M0/Off duty.. ]"42}dennis duty> WA6NIA-14>APD214,RELAY*,WIDE,WIDE:= N/ Wk191/000/Mic-E/M0/Off duty.. ]"4,} duty> WA6NIA-14>APD214,RELAY*,WIDE,WIDE:= N/ Wk191/000/Mic-E/M0/Off duty.. ]"4.}dennis WA6NIA-14>APD214,RELAY*,WIDE,WIDE:= N/ Wk191/000/Mic-E/M0/Off duty.. ]"4(}

11 April 2001APRS - Automatic Position Reporting System Where do I find APRS on the air? HF –Typical operation is on 30 meters MHz (this is actually inside the band limit … uses AFSK on LSB) VHF –National APRS freq MHz –This is a very active frequency in Southern California Something new! ARISS - International Space Station –Uplink: –Downlink: –Route info: NOCALL

11 April 2001APRS - Automatic Position Reporting System Internet Resources Information – – – – APRS servers on the ‘net – and mirrors connects with Telnet from WinAPRS or APRS+ Provides real-time, world-wide display – Can be accessed by anyone example: Software sources –TAPR: WinAPRS APRS+ –PocketAPRS

11 April 2001APRS - Automatic Position Reporting System Demo Configuration In the conference room –Kenwood TH-D-7G (WA6NIA-1) Dual-band (VHF/UHF) data radio with built-in APRS-capable TNC Garmin eMap GPS receiver with interconnecting cable –Notebook with WinAPRS –Palm III with PocketAPRS In the parking lot: –Kenwood TM-D700A (WA6NIA-14) –Garmin Street Pilot GPS with interconnecting cable (No waypoint display … NMEA out only)

11 April 2001APRS - Automatic Position Reporting System Demo WA6NIA-14: –beacons on five minute intervals –parked in FU parking lot WA6NIA-1 –should display WA6NIA-14 and possibly others stations displayed depends on nearby RELAY or WIDE digi