Presentation on theme: "APRS in Wisconsin The Automated Packet Reporting System by: Michael Martens, KB9VBR and Mark Rasmussen, N9MEA."— Presentation transcript:
APRS in Wisconsin The Automated Packet Reporting System by: Michael Martens, KB9VBR and Mark Rasmussen, N9MEA
Overview Introduction Protocol and Implementation Software Hardware Network
APRS is: A one-to-many, unconnected packet protocol. A tactical protocol designed for local RF use. A protocol with many reporting capabilities. A protocol with SMS capabilities. A protocol also adapted to the Internet. A protocol with extensive flexibility built-in. A protocol still under development.
Introduction APRS, the Automated Packet Reporting System, is an open system that uses unconnected AX.25 radio packets to transmit and collect data. This data is usually overlaid on a map
Uses of APRS Using GPS data to track vehicle location Sending short, tactical bulletins and messages between stations Transmitting data collected by a weather station
The APRS Network Home stations Mobile and Portable GPS enabled stations (trackers) Digipeaters (Wide-area and Fill-in) Internet I-Gates Automatic Weather Stations
What is needed to begin Computer with APRS software installed Terminal Node Controller (TNC) VHF transceiver and antenna GPS required for mobile stations only
APRS Data Flow
APRS Frequencies VHF MHz HF MHz LSB Experimental work is being done on other frequencies.
APRS Raw Packet KB9DED>APW251,W9SM-10*,WIDE4-4,qAo, N9SDL:= N/ W- WinAPRS WIMARWAUSAU Originator Path Location Status Application
APRS Paths WIDEn-N (ex, WIDE3-3) WIn-N (ex WI2-2, keeps packets within the state of Wisconsin) Named Path (KC9NW-10, KB9VBR) Relay and Trace (Obsolete, Do Not Use)
WIDE and WIDEn-N Digipeaters acknowledge WIDE paths Home stations should not set myalias to Wide WIDEn-N is not the same as WIDE (WIDE3-3 is not the same as WIDE,WIDE,WIDE)
Named Paths Most efficient form of message propagation Only the station with the matching Alias will digipeat the message AB9PJ-4, N9QIP-10, K9ABC-1
WIn-N Keeps APRS Packets within a geographic location, in this case Wisconsin Reduces APRS overload as packets won’t propagate beyond their geographic confines Great for public service event stations (eg walks, parades, races, etc)
Best Path to Use: In the Wausau area: W9SM-1, WIDE2-2 If you are mobile: WIDE1-1, WIDE2-2 If you don’t want your packets to leave the state WI2-2
How APRS Packets Propagate
APRS Real Time Propagation
SSID Special Station Identifier (SSID) allows multiple stations with the same callsign to coexist on the network. Home stations have no SSID Digipeaters may use the ID -1 (W9SM-1) Mobile Stations may use the ID -9 (KB9VBR-9) Kenwood APRS radios may use -7 (WA9NBC-7)
SSID Suggestions No SSID - Home Station, Home Station running I-Gate. -1 Digipeater, Home Station running a Wide1-1 Digi, WX Digipeater -2 Digipeater [#2 or] on 70CM -3 Digipeater [#3] -4 HF to VHF Gateway -5 I-Gate (Not home station) -6 is for Operations via Satellite -7 Kenwood D7 HH -8 is for boats, sailboats and ships (maybe in the future) -9 is for Mobiles -10 is for operation via the internet only -11 is for APRS touch-tone users (and the occasional Balloons) -12 Portable Units such as Laptops, Camp Sites etc. -14 is for Truckers -15 is for HF
WinAPRS/MacAPRS Very easy to use Uses USGS Tiger maps and integrates with Precision Maps from Undertow Software Also uses old style APRSDOS vector maps.
UI-View Lots of features, more complex interface Handles plug-ins. Vibrant developer network Uses raster maps. Integrates with Precision maps. Plug-ins for Street Atlas, Mapblast, and Tiger Maps
APRSDos web.usna.navy.mil/~bruninga/aprs.html The original APRS application. Development going back to 1992 Very rudimentary maps Has satellite tracking features, network utilization analysis, and direction finding support
APRSpoint Easy to use, familiar Microsoft style interface Integrates with Microsoft Streets and Trips exclusively
APRS Software All APRS software applications are shareware and require a registration fee for continued use. Registration fees range in cost from charity donation to around $100. Some applications may also require you to purchase a map package.
APRS Hardware VHF Transceiver Terminal Node Controller (TNC) GPS for mobile operation
VHF Transceiver Any 2 meter radio will work as long as it will work on csq. You will need to make a cable to connect mic audio, RX audio, and PTT to the TNC.
APRS Enabled Radios Some radios have built in TNCs for direct connection to a computer or APRS interaction right on the display. Alinco DR-135 Kenwood TH-D7A Kenwood D-700A
TNC The TNC, also known as a radio modem converts the digital information from the computer and/or GPS into audio tones. The APRS network runs at 1200 baud The TNC communicates with the computer via the serial port.
TNC The most common TNC is the Kantronics KPC-3+ TNCs can be purchased used on EBay for about $ Kantronics TNCs will be higher in price. Older TNCs work great for home stations, ex: AEA PK-12, MFJ 1270 series, KPC-3 Tiny Trak 3 and 4 - Open Tracker 1+ and 2
Kantronics KPC-3+ About $230 retail Has a dual port that allows simultaneous computer and GPS connection Great TNC choice for running an APRS computer in a vehicle Kantronics KPC-3+
Tiny Trak 4 and Open Tracker 2 About $65-$100 retail Has a dual port that allows simultaneous computer and GPS connection Cheaper than a regular TNC but has limitations Tiny Trak 4Open Tracker 2
Tiny Trak 3 and Open Tracker 1+ About $32 or $33 (kit) - $42 or $46 (built) retail Has a single port that only allows connection to a GPS Cheaper than a regular TNC but it only transmits data Tiny Trak 3Open Tracker 1+
Global Positioning System (GPS) A GPS unit is required for real time mobile tracking GPSs come in many different forms Any GPS with NMEA output will work with APRS Garmin Streetpilot Garmin Etrex Legend
Home Station Equipment Watching on RF –Radio –TNC –Computer Watching on the Internet –Computer
Tracker Station Equipment There are two ways to send out your position when mobile. Dedicated APRS system Mic-E system
Dedicated Tracker Station Equipment With computer –Radio –TNC (High end unit) –Computer –GPS Without computer –Radio –TNC (simple unit) –GPS
Dedicated Equipment Pros and Cons Pros –Can watch other units on map and send messages –Position is sent out at predetermined intervals –Separate radio system in the car in case your 2M voice radio dies –Separate radio infrastructure in case your repeater goes down –Could also be used as Winlink or Packet station Cons –Another radio in the car –More 2M RF to interfere with your local repeater traffic –Higher cost because of more equipment
Mic-E Station Equipment GPS Cheaper Encode only TNC Uses your normal voice radio, no extra radio
Mic-E Pros and Cons Pros –Don’t have to install another radio in the car –Cheaper than the dedicated equipment way –Can use the cheaper encode only TNC Cons –Can not track other units on a map –Can not send messages to other units –Position only goes out when you talk on the radio –Position on map could be very old because you didn’t talk on the radio –More expensive for the repeater owners –Won’t work on all repeater systems –No back-up radio if your voice radio fails –If the repeater fails, no one sees your position
Putting it all together Mobile tracking unit with integrated computer. Computer running WinAPRS Transceiver tuned to csq KPC-3+ TNC GPS
Putting it all together Portable tracker box GPSAntenna Tracker Radio
Putting it all together Bike Mobile APRS GPSAntenna Who could this be? Radio/Tracker
Putting it all together APRS Home Station - notice no GPS RadioTNC Computer
Digipeaters Digipeaters extend the coverage of the portable and mobile units much like a repeater but operating on a simplex frequency. They are usually located at a high location on a tower but can also be located at someone’s home to help fill in a certain area.
Digipeaters in the NE District
Estimated APRS Coverage to a Mobile
APRS Network I-Gates are internet gateways that expand the reach of APRS worldwide. An I-Gate listens to the local RF channel and relays the information into an APRS Internet data stream. I-Gates also relay information from the Internet data stream to a local RF station
Benefits of I-Gates Reduces RF network congestion Increases the trackability of mobile stations Allows RF access of weather service bulletins and alerts Can set up an APRS station without a radio and TNC Any APRS station can be queried at (map.findu.com/kb9vbr)
Weather Service Messages The National Weather EMWIN data stream is injected into the APRS data stream. Alerts and messages can be color coded on the APRS maps.
APRS and the Internet UI-View radar plug-in superimposes NWS radar data onto the APRS screen. WinAPRS has a similar feature.
Weather Stations You can also send out your local weather information if you have the right equipment. 2M radio on TNC Weather Station Possibly a computer
APRS Satellites PCSAT2 is the second generation APRS satellite PCSAT1, launched in 2001, is no longer fully operational PCSAT2 launched August of 2005 has returned to earth with STS-115 in 2006 The ISS is capable of digipeating APRS when the radio is not used for other activities.
APRS Books APRS, Moving hams on Radio and the Internet A good basic introduction to the mode OUT OF PRINT ISBN
APRS Books VHF Digital Handbook Covers APRS, Packet, D-STAR, and more 2008 printing, $19.95 ISBN
For Additional Information Wisconsin APRS discussion group: groups.yahoo.com/group/wisconsinaprs web site: KB9VBR APRS page: Michael Martens: Mark Rasmussen: