APRSAPRSThe Automated Packet The Automated Packet

Reporting SystemReporting Systemby: Andy Zwirko - K1RAby: Andy Zwirko - K1RA

k1ra@k1ra.usk1ra@k1ra.ushttp://www.k1ra.us/http://www.k1ra.us/

Presentation OverviewPresentation Overview

Definition, purpose and scope of APRSDefinition, purpose and scope of APRS APRS Pitfalls & MisconceptionsAPRS Pitfalls & Misconceptions History of APRS and its inventorHistory of APRS and its inventor Station HardwareStation Hardware Network and data flow Network and data flow APRS protocol and raw packet decodesAPRS protocol and raw packet decodes SoftwareSoftware FARA members on APRSFARA members on APRS The future of APRS and opportunitiesThe future of APRS and opportunities LinksLinks

What is APRS?What is APRS?

APRS = Automatic APRS = Automatic PacketPacket Reporting Reporting SystemSystem

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

APRS data is usually APRS data is usually overlaid on a mapoverlaid on a map

APRS is:APRS is:

A two-way information exchange using radioA two-way information exchange using radio A one-to-many, unconnected packet protocol.A one-to-many, unconnected packet protocol. A tactical protocol designed for local RF use.A tactical protocol designed for local RF use. A protocol with many reporting capabilities.A protocol with many reporting capabilities. A protocol with SMS capabilities.A protocol with SMS capabilities. A protocol also adapted to the Internet.A protocol also adapted to the Internet. A protocol with extensive flexibility built-in.A protocol with extensive flexibility built-in. A protocol still under development.A protocol still under development.

Purposes of APRSPurposes of APRS Immediate digital information Immediate digital information

exchange between all participants in exchange between all participants in a local area or event. This includes:a local area or event. This includes: Positions and status of all stations and objects Positions and status of all stations and objects

(GPS)(GPS) Messages, Bulletins and AnnouncementsMessages, Bulletins and Announcements Assist in Search and Rescue operationsAssist in Search and Rescue operations Gather and track weather data and telemetry Gather and track weather data and telemetry

(satellite, remote)(satellite, remote) DF bearings and signal strengths for quick DF bearings and signal strengths for quick

transmitter huntingtransmitter hunting RF Connectivity plots of all stationsRF Connectivity plots of all stations Local OBJECTS on a common map display for Local OBJECTS on a common map display for

all usersall users Local Freqs, Nets, Meetings, Marathons, Local Freqs, Nets, Meetings, Marathons,

Races, EventsRaces, Events

Voice Alert

Signal Finding

Nets &

Meeting

s

Wx

Info

Field Data Traffic

FrequencyRF

Ranging

APRS Network NodesAPRS Network Nodes

Home stationsHome stations Mobile and Portable GPS tracker stationsMobile and Portable GPS tracker stations Automatic Weather StationsAutomatic Weather Stations Digipeaters Digipeaters Internet I-GatesInternet I-Gates

Scope of APRSScope of APRS

APRS Pitfalls & APRS Pitfalls & MisconceptionsMisconceptions

That APRS is just Vehicle Tracking vs. a Real-Time Information Distribution System. 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). 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. 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. Using APRS clients that only do maps and ignore many of the APRS fundamentals. Failure to understand the importance of ObjectsFailure to understand the importance of Objects Not understanding the APRS operator’s role as a Data Input (Objects, Messages, etc) Not understanding the APRS operator’s role as a Data Input (Objects, Messages, etc) Failure to use real-time messaging: Failure to use real-time messaging: Not using the D7 and D700 as data entry and clipboard display units at field events. 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. 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 display APRS symbols with all their attributes and colors Failure to manage the network by adjusting a local digipeater for the situation at hand. 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. Not realizing the importance of Voice Operating frequencies in APRS. Failure to implement the original APRS Centralized Common Bulletin Board concept. Failure to implement the original APRS Centralized Common Bulletin Board concept. Ignore the fundamental Decay Algorithm to accelerate new data, and decay old data! Ignore the fundamental Decay Algorithm to accelerate new data, and decay old data!

Founder & HistoryFounder & History Bob Bruninga, WB4APR is Bob Bruninga, WB4APR is

considered the “Father of considered the “Father of APRS” and is still active on a APRS” and is still active on a daily basis.daily basis.

Bob is a member of the Bob is a member of the United States Naval Academy United States Naval Academy Aerospace Engineering Dept.Aerospace Engineering Dept.

APRS was developed in the APRS was developed in the early 1990's for local tactical early 1990's for local tactical digital communications, digital communications, situational awareness and situational awareness and TWO-WAY information TWO-WAY information exchange using Amateur exchange using Amateur radio.radio.

Bob Bruninga first used to Bob Bruninga first used to track horses in 1994track horses in 1994

Designed to “beDesigned to “be a cost a cost effective mapping program effective mapping program that would allow positioning that would allow positioning of mobile stations using GPS of mobile stations using GPS receivers.” receivers.”

What is needed to What is needed to participate?participate?

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

Operating via the InternetOperating via the Internet Computer with browser or APRS softwareComputer with browser or APRS software Mobile phone with browser or APRS Mobile phone with browser or APRS

softwaresoftware

VHF TransceiverVHF Transceiver

Any 2 meter radio will work as long as it Any 2 meter radio will work as long as it will work on 144.390 carrier squelchwill work on 144.390 carrier squelch

You will need to make a cable to connect You will need to make a cable to connect mic audio, RX audio, and PTT to the TNCmic audio, RX audio, and PTT to the TNC

TNC Encode/DecodeTNC Encode/Decode

Known as a radio modem, converts the Known as a radio modem, converts the digital information from the computer digital information from the computer and/or GPS into audio tones and AX.25and/or GPS into audio tones and AX.25

The APRS network runs at 1200 baudThe APRS network runs at 1200 baud

TNC Encode (only)TNC Encode (only)

Cheaper than a regular TNC ($30-Cheaper than a regular TNC ($30-45) but it only transmits data45) but it only transmits data

Has a single port that only allows Has a single port that only allows connection to a GPSconnection to a GPS

Tiny Trak 3 Open Tracker 1+

APRS Enabled RadiosAPRS Enabled Radios

Some radios have built in TNCs for Some radios have built in TNCs for direct connection to a computer or direct connection to a computer or APRS interaction right on the APRS interaction right on the display.display.

Alinco DR-135 Kenwood TH-D7A Kenwood D-700A

GPS ReceiversGPS Receivers

Uses military controlled Uses military controlled GPS satellites available GPS satellites available to general publicto general public

Typical positions Typical positions accuracy ranges from accuracy ranges from 1-5 feet1-5 feet

GPS must output NMEA GPS must output NMEA to work with APRSto work with APRS

Many models available Many models available for under $100for under $100

Serial, USB, Bluetooth Serial, USB, Bluetooth interfaces available to interfaces available to PCPC

Station ConfigurationsStation Configurations

Dedicated APRS Dedicated APRS systemsystem GPSGPS ComputerComputer Radio (separate)Radio (separate) TNC (encode/decode)TNC (encode/decode)

Mic-E APRS systemMic-E APRS system Radio (shared)Radio (shared) TNC (encode only)TNC (encode only) GPSGPS

Dedicated Equipment Pros / Dedicated Equipment Pros / ConsCons

ProsPros Can watch other units on map and send messagesCan watch other units on map and send messages Position is sent out at predetermined intervalsPosition is sent out at predetermined intervals Separate radio system in car in case your 2M voice Separate radio system in car in case your 2M voice

radio diesradio dies Separate radio infrastructure in case your repeater Separate radio infrastructure in case your repeater

goes downgoes down Could also be used as Winlink or Packet stationCould also be used as Winlink or Packet station

ConsCons Another radio in the carAnother radio in the car More 2M RF to interfere with your local repeater More 2M RF to interfere with your local repeater

traffictraffic Higher cost because of more equipmentHigher cost because of more equipment

Mic-E Pros and ConsMic-E Pros and Cons

ProsPros Don’t have to install another radio in the carDon’t have to install another radio in the car Cheaper than the dedicated equipment wayCheaper than the dedicated equipment way Can use the cheaper encode only TNCCan use the cheaper encode only TNC

ConsCons Can not track other units on a mapCan not track other units on a map Can not send messages to other unitsCan not send messages to other units Position only goes out when you talk on the radioPosition only goes out when you talk on the radio Position on map could be very old since you didn’t talk Position on map could be very old since you didn’t talk

on radioon radio More expensive for the repeater ownersMore expensive for the repeater owners Won’t work on all repeater systemsWon’t work on all repeater systems No back-up radio if your voice radio failsNo back-up radio if your voice radio fails If the repeater fails, no one sees your positionIf the repeater fails, no one sees your position

Home / Fixed SystemHome / Fixed System

APRS Home Station without a GPSAPRS Home Station without a GPS

Radio

TNC

Computer

Trackers (one-way)Trackers (one-way)

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.

One-way APRS is not normally recommended. APRS is a Network. We want good communications among all participants for maximum utility.

Tracker SystemTracker System

Portable tracker box, with no compute or displayPortable tracker box, with no compute or display

GPS 2m Antenna Tracker Radio

APRS Network NodesAPRS Network Nodes

StationsStations HomeHome MobileMobile DigipeaterDigipeater

ss SatellitesSatellites I-GatesI-Gates

APRS is a Network intended for real-time, two-way tactical information exchange.

SSID SuggestionsSSID SuggestionsSpecial Station Identifier (SSID) allows multiple stations with the Special Station Identifier (SSID) allows multiple stations with the

same callsign to coexist on the networksame callsign to coexist on the network

No SSID - Home Station, Home Station running I-GateNo SSID - Home Station, Home Station running I-Gate-1 Digipeater, Home Station running a Wide1-1 Digi, WX Digipeater-1 Digipeater, Home Station running a Wide1-1 Digi, WX Digipeater-2 Digipeater [#2 or] on 70CM-2 Digipeater [#2 or] on 70CM-3 Digipeater [#3]-3 Digipeater [#3]-4 HF to VHF Gateway-4 HF to VHF Gateway-5 I-Gate (Not home station) -5 I-Gate (Not home station) -6 is for Operations via Satellite-6 is for Operations via Satellite-7 Kenwood D7 HH-7 Kenwood D7 HH-8 is for boats, sailboats and ships (maybe 802.11 in the future)-8 is for boats, sailboats and ships (maybe 802.11 in the future)-9 is for Mobiles-9 is for Mobiles-10 is for operation via the internet only-10 is for operation via the internet only-11 is for APRS touch-tone users  (and the occasional Balloons)-11 is for APRS touch-tone users  (and the occasional Balloons)-12 Portable Units such as Laptops, Camp Sites etc.-12 Portable Units such as Laptops, Camp Sites etc.-14 is for Truckers-14 is for Truckers-15 is for HF-15 is for HF

DigipeatersDigipeaters

Extend the coverage of Extend the coverage of the portable and mobile the portable and mobile unitsunits

Much like a repeater Much like a repeater but operating on a but operating on a simplex frequency. simplex frequency.

Usually located at a Usually located at a high location on a tower high location on a tower

Can also be located at Can also be located at someone’s home to help someone’s home to help fill in a certain area.fill in a certain area.

Paths WIDEn-N vs. Paths WIDEn-N vs. NamedNamed

Digipeaters acknowledge WIDEn-N pathsDigipeaters acknowledge WIDEn-N paths WIDEn-N paths are decremented for each WIDEn-N paths are decremented for each

hophop Never need more than WIDE2-2Never need more than WIDE2-2

Named path most efficient form of message Named path most efficient form of message propagationpropagation

Only the station with the matching Alias will Only the station with the matching Alias will digipeat the messagedigipeat the message

WD4HDL-1, N3HF-1WD4HDL-1, N3HF-1

I-Gates – Tier2 Global I-Gates – Tier2 Global NetNet

I-Gates are internet gateways that expand the I-Gates are internet gateways that expand the reach of APRS worldwide – www.aprs2.net reach of APRS worldwide – www.aprs2.net

An I-Gate listens to the local RF channel and An I-Gate listens to the local RF channel and relays the information into an APRS Internet relays the information into an APRS Internet data stream.data stream.

I-Gates also relay information from the I-Gates also relay information from the Internet data stream to a local RF station Internet data stream to a local RF station

Benefits of I-GatesBenefits of I-Gates

Reduces RF network congestionReduces RF network congestion Increases the trackability of mobile Increases the trackability of mobile

stationsstations Allows RF access of weather service Allows RF access of weather service

bulletins and alertsbulletins and alerts Can set up an APRS station without Can set up an APRS station without

a radio and TNCa radio and TNC Any APRS station can be queried at Any APRS station can be queried at

www.findu.com or www.aprs.fi www.findu.com or www.aprs.fi

Typical Local APRS Typical Local APRS NetworkNetwork

Internet Gateway

Digipeater

Home Fixed

Digipeater

Portables

Mobiles

APRS Data FlowAPRS Data Flow

APRS ProtocolAPRS Protocol

APRS Data TypesAPRS Data Types

APRS Position ProtocolAPRS Position Protocol

APRS Object ProtocolAPRS Object Protocol

APRS Message ProtocolsAPRS Message Protocols

APRS Map SymbolsAPRS Map Symbols

Raw APRS PacketsRaw APRS Packets

Decoded APRS PacketsDecoded APRS Packets

• Location and Status

Decoded APRS PacketsDecoded APRS Packets

• Location and weather report

APRS SoftwareAPRS Software

PC ClientsPC Clients APRSDosAPRSDos WinAPRS/WinAPRS/

MacAPRSMacAPRS UI-ViewUI-View APRSpointAPRSpoint APRS+SAAPRS+SA Xastir (Linux / Xastir (Linux /

Unix)Unix) Internet BrowserInternet Browser

PDA ClientsPDA Clients AprsCEAprsCE APRS-GoAPRS-Go APRS-PalmAPRS-Palm

I-GateI-Gate JavAPRSJavAPRS AHubAHub aprsDaprsD NOSaprsNOSaprs

APRSDosAPRSDos

The original APRS application. The original APRS application. Development going back to 1992Development going back to 1992

Very rudimentary mapsVery rudimentary maps Has satellite tracking features, network Has satellite tracking features, network

utilization analysis, and direction finding utilization analysis, and direction finding supportsupport

Price – freePrice – free http://http://

www.usna.edu/Users/aero/bruninga/aprs.hwww.usna.edu/Users/aero/bruninga/aprs.htmltml

APRSDosAPRSDos

WinAPRSWinAPRS

Uses USGS Tiger maps and integrates Uses USGS Tiger maps and integrates with Precision Maps from Undertow with Precision Maps from Undertow SoftwareSoftware

Also uses old style APRSDOS vector Also uses old style APRSDOS vector maps.maps.

NWS weather data overlay capabilityNWS weather data overlay capability Price – freePrice – free http://www.winaprs.com http://www.winaprs.com Also hosts X-APRS, MacAPRS, dosAPRSAlso hosts X-APRS, MacAPRS, dosAPRS

WinAPRSWinAPRS

UI-ViewUI-View

Lots of features, more complex interfaceLots of features, more complex interface Handles plug-ins (ex: NWS radar, Sat. Handles plug-ins (ex: NWS radar, Sat.

telemetry)telemetry) Vibrant developer networkVibrant developer network Uses user generated, or raster maps. Uses user generated, or raster maps. Integrates with Precision maps. Plug-ins Integrates with Precision maps. Plug-ins

for Street Atlas, Mapblast and Tiger for Street Atlas, Mapblast and Tiger MapsMaps

Price – freePrice – free http://www.uiview.org http://www.uiview.org

UI-ViewUI-View

UI-ViewUI-View

APRSpointAPRSpoint

Easy to use, familiar Microsoft style Easy to use, familiar Microsoft style interfaceinterface

Requires MapPoint 2004, 2006, Requires MapPoint 2004, 2006, 2009 or 20102009 or 2010

Provides for routingProvides for routing Price – $77 with maps, $47 without Price – $77 with maps, $47 without

mapsmaps http://www.aprspoint.com http://www.aprspoint.com

APRSpointAPRSpoint

APRS+SAAPRS+SA

Interfaces with Delorme Street Atlas USAInterfaces with Delorme Street Atlas USA Offers text-to-speech capabilitiesOffers text-to-speech capabilities Price - freePrice - free

APRS-GoAPRS-Go

Windows Windows Mobile / PDAMobile / PDA

Uses OSM Uses OSM public map public map setset

Works with Works with many TNCsmany TNCs

Price – freePrice – free PC version PC version

tootoohttp://http://www.aprsgo.com/www.aprsgo.com/

Online APRS ResourcesOnline APRS Resources

While APRS is While APRS is intended to be a intended to be a primary network primary network that does not that does not require the require the Internet, many Internet, many users use online users use online national databases national databases to track stationsto track stations

APRS Real Time APRS Real Time PropagationPropagation

http://www.mountainlake.k12.mn.us/ham/aprs

www.APRS.fi - www.APRS.fi - MappingMapping

www.APRS.fi - Weatherwww.APRS.fi - Weather

www.APRS.fi - Beaconswww.APRS.fi - Beacons

www.findU.com - Mappingwww.findU.com - Mapping

www.findU.com – Nearby-In www.findU.com – Nearby-In RangeRange

Google for “USNA Buoy” Select USNA-1

www.findU.com - Messageswww.findU.com - Messages

FARA on APRSFARA on APRS

KX4O – John – Mobile Tracker & Golden KX4O – John – Mobile Tracker & Golden PacketPacket

W4IFI – Randy – Mobile Tracker & WxW4IFI – Randy – Mobile Tracker & Wx KD6AKC – Mark – Mobile TrackerKD6AKC – Mark – Mobile Tracker N4YXW – Chuck – Internet GatewayN4YXW – Chuck – Internet Gateway KW4VA – Andy (K1RA) – Echolink gatewayKW4VA – Andy (K1RA) – Echolink gateway

APRS Golden Packet APRS Golden Packet 2010 2010

APRS Golden Packet APRS Golden Packet 2010 2010

APRS Golden Packet APRS Golden Packet 2010 2010

Future of APRSFuture of APRSInternational Space International Space

Station (ISS)Station (ISS) The ISS was equiped The ISS was equiped

with an APRS receiver on with an APRS receiver on 145.825 recently145.825 recently

Used for crew to send Used for crew to send messages to friends, messages to friends, family, and amateur family, and amateur radio operatorsradio operators

Designed to track ISS in Designed to track ISS in spacespace

Used as a space Used as a space digipeater in the APRS digipeater in the APRS space satellite space satellite constellationconstellation

More info at More info at www.ariss.netwww.ariss.net

APRS Satellite Tracking & APRS Satellite Tracking & Reporting SystemReporting System

ASTARS - http://www.aprs.org/astars.html ASTARS - http://www.aprs.org/astars.html

APRS OpportunitiesAPRS Opportunities

APRStt (APRS touchtone decoding)APRStt (APRS touchtone decoding) Simple DTMF memory Simple DTMF memory

One button reports Position, Freq. and StatusOne button reports Position, Freq. and Status

On every voice repeaterOn every voice repeater

On every IRLP nodeOn every IRLP node

On every Echolink nodeOn every Echolink node

Any where on .52!!Any where on .52!!

ONLY NEEDS local software upgradeONLY NEEDS local software upgrade

AVRSAVRS (Automatic Voice Relay System) Global VOIP via (Automatic Voice Relay System) Global VOIP via

APRSAPRS Uses APRS message to set up callUses APRS message to set up call

Automatically links to Echolink or IRLPAutomatically links to Echolink or IRLP

Radio auto-QSY’s to make link (Ham Radio Cell phone from Radio auto-QSY’s to make link (Ham Radio Cell phone from

Mobile)Mobile)

Simple DTMF memory - One button puts you in APRS (Simple DTMF memory - One button puts you in APRS (Position, Frequency and StatusPosition, Frequency and Status)!)! DTMF on voice freq translated to packet on APRS channel (or direct to APRS-IS)DTMF on voice freq translated to packet on APRS channel (or direct to APRS-IS) Position is 10 mile ambiguity using repeater posit (Position is 10 mile ambiguity using repeater posit (or 60 mile ambiguity out westor 60 mile ambiguity out west)) Frequency in packet is Frequency of RepeaterFrequency in packet is Frequency of Repeater If Echolink or IRLP, APRS packet includes node number!If Echolink or IRLP, APRS packet includes node number!

APRStt (Touchtone)APRStt (Touchtone)

• For WB4APR, the DTMF Sends: For WB4APR, the DTMF Sends: ##A922444427A77DA922444427A77D

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

• WB4APR-11>APRStt,WIDE1-1:!DDM_.__N/DDDM_.__W$146.895MHz T107 WB4APR-11>APRStt,WIDE1-1:!DDM_.__N/DDDM_.__W$146.895MHz T107 IRLP7070IRLP7070

• Puts you on global map near Baltimore Maryland, with your Puts you on global map near Baltimore Maryland, with your immediate calling frequency, your Tone and your IRLP node immediate calling frequency, your Tone and your IRLP node number.number. That is everything you need to be known to the Global APRS That is everything you need to be known to the Global APRS

system!system!

We have had this since 2001 (in DOS w DTMF chip).We have had this since 2001 (in DOS w DTMF chip).

We need someone to do this with a sound card in windows?We need someone to do this with a sound card in windows?

Build into every Echolink/IRLP node and every Repeater Build into every Echolink/IRLP node and every Repeater

controller with a serial port!controller with a serial port!

Unless we get APRStt and therefore 100% situational awareness Unless we get APRStt and therefore 100% situational awareness

of any Ham mobile or HT then APRS will always be a side show of any Ham mobile or HT then APRS will always be a side show

only used by 10% of any club or organization.only used by 10% of any club or organization.

How about: #B95*234*2D => Milemark #234 on Route 95, northbound

APRStt (Touchtone)APRStt (Touchtone)

DTMF Report shows on APRSDTMF Report shows on APRS CALLSIGN with date and timeCALLSIGN with date and time

Position in vicinity of repeater or APRStt entry pointPosition in vicinity of repeater or APRStt entry point

Voice Operating Frequency, Tone and other infoVoice Operating Frequency, Tone and other info

Node number if Echolink or IRLP, or reverse patch number if Node number if Echolink or IRLP, or reverse patch number if

RepeaterRepeater

147.105MHz T107 R30m

APRStt (Touchtone)APRStt (Touchtone)

As simple as adding a DTMF chip to a Micro-Trak

Or adding a DTMF chip to an OT and HT for use in the field at a special event

APRStt (Touchtone)APRStt (Touchtone)

APRStt, maps and eventsAPRStt, maps and events

That APRS is dependent on GPS for its value That APRS is dependent on GPS for its value

(GPS is not required to put things on maps). (GPS is not required to put things on maps).

APRS Voice Alert! APRS Voice Alert!

Voice Alert is effectively 3Voice Alert is effectively 3rdrd Radio channel for the D7 and Radio channel for the D7 and D700 APRS radiosD700 APRS radios

Set the APRS Band A to PL-100 Set the APRS Band A to PL-100 and keep the volume turned up:and keep the volume turned up: You wont hear any packets on 144.39 *You wont hear any packets on 144.39 * But you will hear a voice call using PL-100 on But you will hear a voice call using PL-100 on

144.39144.39 And you will hear* an occasional Ping packet if And you will hear* an occasional Ping packet if

another D700 comes in line-of-site to you, like a another D700 comes in line-of-site to you, like a proximity radar alerting you to local presence.proximity radar alerting you to local presence.

Great for long haul traveling and meeting Great for long haul traveling and meeting other APRS users.other APRS users.

LinksLinks

WB4APR – APRS Home - http://www.aprs.org/ WB4APR – APRS Home - http://www.aprs.org/ APRS Protocol – APRS Protocol – ftp://ftp.tapr.org/aprssig/aprsspec/spec/aprs101/APRS101.pdfftp://ftp.tapr.org/aprssig/aprsspec/spec/aprs101/APRS101.pdf ftp://www.tapr.org/aprssig/aprsspec/spec/aprs101m/ftp://www.tapr.org/aprssig/aprsspec/spec/aprs101m/ APRS Info Wiki – http://info.aprs.net/ APRS Info Wiki – http://info.aprs.net/ APRSSIG Users Group – http://tapr.org/mailman/listinfo/aprssig APRSSIG Users Group – http://tapr.org/mailman/listinfo/aprssig APRS Apps - APRS Apps - http://http://www.eskimo.com/~archer/aprs_capabilities.htmlwww.eskimo.com/~archer/aprs_capabilities.html APRS-IS – Internet Spec Info - http://www.aprs-is.net/ APRS-IS – Internet Spec Info - http://www.aprs-is.net/ APRS Tier2 Network – http://www.aprs2.net APRS Tier2 Network – http://www.aprs2.net APRS.fi Map & Database – http://www.aprs.fi/ APRS.fi Map & Database – http://www.aprs.fi/ OpenAPRS Map – http://www.openaprs.net/ OpenAPRS Map – http://www.openaprs.net/ FindU APRS Map & Database – http://www.findu.com/ FindU APRS Map & Database – http://www.findu.com/ APRS & Edge of Space Science – http://www.eoss.org/aprs APRS & Edge of Space Science – http://www.eoss.org/aprs APRS on ISS – APRS on ISS –

http://www.usna.edu/Users/aero/bruninga/iss-faq.htmlhttp://www.usna.edu/Users/aero/bruninga/iss-faq.html APRS Balloons – APRS Balloons – http://www.aprs.org/balloon-n8pk.htmlhttp://www.aprs.org/balloon-n8pk.html PCSAT2 – PCSAT2 – http://www.usna.edu/Users/aero/bruninga/pcsat2.htmlhttp://www.usna.edu/Users/aero/bruninga/pcsat2.html Meteor Scatter – Meteor Scatter – http://http://

www.usna.edu/Users/aero/bruninga/meteors.htmlwww.usna.edu/Users/aero/bruninga/meteors.html