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FARA-APRS-2010 Powered By Docstoc
The Automated Packet
  Reporting System
  by: Andy Zwirko - K1RA
          Presentation Overview

   Definition, purpose and scope of APRS
   APRS Pitfalls & Misconceptions
   History of APRS and its inventor
   Station Hardware
   Network and data flow
   APRS protocol and raw packet decodes
   Software
   FARA members on APRS
   The future of APRS and opportunities
   Links
                What is APRS?

   APRS = Automatic Packet
    Reporting System

   APRS is an open system that
    uses unconnected AX.25
    radio packets to transmit and
    collect data.

   APRS data is usually overlaid
    on a map
                     APRS is:

   A two-way information exchange using radio
   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.
                      Purposes of APRS
   Immediate digital information exchange
    between all participants in a local area or
    event. This includes:
        Positions and status of all stations and objects (GPS)
        Messages, Bulletins and Announcements
        Assist in Search and Rescue operations
        Gather and track weather data and telemetry (satellite,
        DF bearings and signal strengths for quick transmitter
        RF Connectivity plots of all stations
        Local OBJECTS on a common map display for all
        Local Freqs, Nets, Meetings, Marathons, Races, Events

                                 Field Data
          APRS Network Nodes
   Home stations
   Mobile and Portable GPS tracker stations
   Automatic Weather Stations
   Digipeaters
   Internet I-Gates
Scope of APRS
       APRS Pitfalls & Misconceptions

   That APRS is just Vehicle Tracking vs. a Real-Time Information Distribution System.
   That APRS is dependent on GPS for its value (GPS is not needed. See Objects).
   Failure to use the APRS built-in Mile-Marks for tracking all other non-APRS mobiles.
   Using APRS clients that only do maps and ignore many of the APRS fundamentals.
   Failure to understand the importance of Objects
   Not understanding the APRS operator’s role as a Data Input (Objects, Messages, etc)
   Failure to use real-time messaging:
   Not using the D7 and D700 as data entry and clipboard display units at field events.
   Too much focus on Large Screen Displays vs. Individual Operator displays for events.
   Failure to display APRS symbols with all their attributes and colors
   Failure to manage the network by adjusting a local digipeater for the situation at hand.
   Not realizing the importance of Voice Operating frequencies in APRS.
   Failure to implement the original APRS Centralized Common Bulletin Board concept.
   Ignore the fundamental Decay Algorithm to accelerate new data, and decay old data!
Founder & History
             Bob Bruninga, WB4APR is
              considered the “Father of APRS”
              and is still active on a daily basis.
             Bob is a member of the United
              States Naval Academy Aerospace
              Engineering Dept.
             APRS was developed in the early
              1990's for local tactical digital
              communications, situational
              awareness and TWO-WAY
              information exchange using
              Amateur radio.
             Bob Bruninga first used to track
              horses in 1994
             Designed to “be a cost effective
              mapping program that would allow
              positioning of mobile stations
              using GPS receivers.”
    What is needed to participate?

   Operating via RF
     Radio - VHF transceiver and antenna
     TNC - Terminal Node Controller
     Computer with APRS software installed
     GPS (optional) for mobile stations

   Operating via the Internet
     Computer with browser or APRS software
     Mobile phone with browser or APRS software
              VHF Transceiver
   Any 2 meter radio will work as long as it will
    work on 144.390 carrier squelch
   You will need to make a cable to connect mic
    audio, RX audio, and PTT to the TNC
          TNC Encode/Decode
   Known as a radio modem, converts the digital
    information from the computer and/or GPS
    into audio tones and AX.25
   The APRS network runs at 1200 baud
            TNC Encode (only)

   Cheaper than a regular TNC ($30-45) but it only
    transmits data
   Has a single port that only allows connection to
    a GPS

           Tiny Trak 3            Open Tracker 1+
           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
GPS Receivers

          Uses military controlled GPS
           satellites available to general
          Typical positions accuracy
           ranges from 1-5 feet
          GPS must output NMEA to
           work with APRS
          Many models available for
           under $100
          Serial, USB, Bluetooth
           interfaces available to PC
            Station Configurations

   Dedicated APRS system
       GPS
       Computer
       Radio (separate)
       TNC (encode/decode)

   Mic-E APRS system
       Radio (shared)
       TNC (encode only)
       GPS
    Dedicated Equipment Pros / Cons

   Pros
       Can watch other units on map and send messages
       Position is sent out at predetermined intervals
       Separate radio system in 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 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 since you didn’t talk on 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
             Home / Fixed System

      APRS Home Station without a GPS


Computer                                 Radio
              Trackers (one-way)
One-way APRS is not normally recommended. APRS is a Network. We
want good communications among all participants for maximum utility.

Trackers have no
APRS data display.
So the receiver
should be tuned to a
beaconed Voice
frequency so the
operator can be
involved in the Net!

One-way trackers are good for non-manned assets at large
movement events.. Not as the only APRS asset for a ham.
                       Tracker System

   Portable tracker box, with no compute or display
    GPS   2m Antenna         Tracker       Radio
            APRS Network Nodes

   Stations
      Home
      Mobile

      Digipeaters

      Satellites

      I-Gates

    APRS is a Network intended for real-time, two-way
    tactical information exchange.
                        SSID Suggestions
Special Station Identifier (SSID) allows multiple stations with the same callsign to coexist on
   the network

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 802.11 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

   Extend the coverage of the
    portable and mobile units
   Much like a repeater but
    operating on a simplex
   Usually located at a high
    location on a tower
   Can also be located at
    someone’s home to help fill in a
    certain area.
      Paths WIDEn-N vs. Named

   Digipeaters acknowledge WIDEn-N paths
   WIDEn-N paths are decremented for each hop
   Never need more than WIDE2-2

   Named path most efficient form of message
   Only the station with the matching Alias will digipeat
    the message
   WD4HDL-1, N3HF-1
      I-Gates – Tier2 Global Net

   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
   Any APRS station can be queried at or
Typical Local APRS Network

  Internet               Digipeater



  Digipeater                Portables
APRS Data Flow
APRS Protocol
APRS Data Types
APRS Position Protocol
APRS Object Protocol
APRS Message Protocols
APRS Map Symbols
Raw APRS Packets
          Decoded APRS Packets
• Location and Status
          Decoded APRS Packets
• Location and weather report
                 APRS Software
   PC Clients                   PDA Clients
     APRSDos                      AprsCE
                                   APRS-Go
     WinAPRS/MacAPRS
                                   APRS-Palm
     UI-View

     APRSpoint
                                 I-Gate
     APRS+SA                      JavAPRS
     Xastir (Linux / Unix)        AHub
     Internet Browser             aprsD
                                   NOSaprs

   The original APRS application. Development
    going back to 1992
   Very rudimentary maps
   Has satellite tracking features, network
    utilization analysis, and direction finding support
   Price – free

   Uses USGS Tiger maps and integrates with
    Precision Maps from Undertow Software
   Also uses old style APRSDOS vector maps.
   NWS weather data overlay capability
   Price – free
   Also hosts X-APRS, MacAPRS, dosAPRS

   Lots of features, more complex interface
   Handles plug-ins (ex: NWS radar, Sat. telemetry)
   Vibrant developer network
   Uses user generated, or raster maps.
   Integrates with Precision maps. Plug-ins for
    Street Atlas, Mapblast and Tiger Maps
   Price – free

   Easy to use, familiar Microsoft style interface
   Requires MapPoint 2004, 2006, 2009 or 2010
   Provides for routing
   Price – $77 with maps, $47 without maps

   Interfaces with Delorme Street Atlas USA
   Offers text-to-speech capabilities
   Price - free

   Windows
    Mobile / PDA
   Uses OSM
    public map set
   Works with
    many TNCs
   Price – free
   PC version too
           Online APRS Resources

   While APRS is
    intended to be a
    primary network that
    does not require the
    Internet, many users
    use online national
    databases to track
APRS Real Time Propagation - Mapping - Weather - Beacons - Mapping – Nearby-In Range
Google for “USNA Buoy” Select USNA-1 - Messages
               FARA on APRS
   KX4O – John – Mobile Tracker & Golden Packet
   W4IFI – Randy – Mobile Tracker & Wx
   KD6AKC – Mark – Mobile Tracker
   N4YXW – Chuck – Internet Gateway
   KW4VA – Andy (K1RA) – Echolink gateway
APRS Golden Packet 2010
APRS Golden Packet 2010
APRS Golden Packet 2010
                  Future of APRS
International Space
  Station (ISS)
   The ISS was equiped
    with an APRS receiver
    on 145.825 recently
   Used for crew to send
    messages to friends,
    family, and amateur
    radio operators
   Designed to track ISS in
   Used as a space
    digipeater in the APRS
    space satellite
   More info at
APRS Satellite Tracking & Reporting
   ASTARS -
                   APRS Opportunities
   APRStt (APRS touchtone decoding)
        Simple DTMF memory
        One button reports Position, Freq. and Status
        On every voice repeater
        On every IRLP node
        On every Echolink node
        Any where on .52!!
        ONLY NEEDS local software upgrade
   AVRS (Automatic Voice Relay System) Global VOIP via APRS
        Uses APRS message to set up call
        Automatically links to Echolink or IRLP
        Radio auto-QSY’s to make link (Ham Radio Cell phone from Mobile)
                         APRStt (Touchtone)

   Simple DTMF memory - One button puts you in APRS (Position, Frequency and Status)!
        DTMF on voice freq translated to packet on APRS channel (or direct to APRS-IS)
        Position is 10 mile ambiguity using repeater posit (or 60 mile ambiguity out west)
        Frequency in packet is Frequency of Repeater
        If Echolink or IRLP, APRS packet includes node number!
                     APRStt (Touchtone)
•   For WB4APR, the DTMF Sends:                 #A922444427A77D

•   This is converted to an APRS packet on the APRS channel as:

•         WB4APR-11>APRStt,WIDE1-1:!DDM_.__N/DDDM_.__W$146.895MHz T107 IRLP7070

•   Puts you on global map near Baltimore Maryland, with your
    immediate calling frequency, your Tone and your IRLP node number.
        That is everything you need to be known to the Global APRS system!
        We have had this since 2001 (in DOS w DTMF chip).
        We need someone to do this with a sound card in windows?
        Build into every Echolink/IRLP node and every Repeater controller
         with a serial port!
   Unless we get APRStt and therefore 100% situational awareness of any Ham
    mobile or HT then APRS will always be a side show only used by 10% of
    any club or organization.
     How about: #B95*234*2D => Milemark #234 on Route 95, northbound
                             APRStt (Touchtone)

   DTMF Report shows on APRS                                             147.105MHz T107 R30m
        CALLSIGN with date and time
        Position in vicinity of repeater or APRStt entry point
        Voice Operating Frequency, Tone and other info
        Node number if Echolink or IRLP, or reverse patch number if Repeater
                     APRStt (Touchtone)

                                     As simple as adding
                                     a DTMF chip to a

Or adding a DTMF
chip to an OT and
HT for use in the
field at a special
            APRStt, maps and events

   That APRS is dependent on GPS for its value
   (GPS is not required to put things on maps).
                     APRS Voice Alert!

   Voice Alert is effectively 3rd Radio
    channel for the D7 and D700 APRS

   Set the APRS Band A to PL-100
    and keep the volume turned up:
        You wont hear any packets on 144.39 *
        But you will hear a voice call using PL-100 on 144.39
        And you will hear* an occasional Ping packet if
         another D700 comes in line-of-site to you, like a
         proximity radar alerting you to local presence.

   Great for long haul traveling and meeting other
    APRS users.
   WB4APR – APRS Home -
   APRS Protocol –
   APRS Info Wiki –
   APRSSIG Users Group –
   APRS Apps -
   APRS-IS – Internet Spec Info -
   APRS Tier2 Network –
 Map & Database –
   OpenAPRS Map –
   FindU APRS Map & Database –
   APRS & Edge of Space Science –
   APRS on ISS –
   APRS Balloons –
   PCSAT2 –
   Meteor Scatter –

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