presented by wes johnston, kd4rdb kd4rdb@usa.net the aprs network

Presented by Wes Johnston, KD4RDB

kd4rdb@usa.net

The APRS NetworkThe APRS Network

Overview of this slide showOverview of this slide show

Introduction

Software and features

Protocol and implementation

Hardware

Network

IntroductionIntroductionAPRS is an open system that uses unconnected

packet radio to transmit and collect data. This data is usually overlaid on a map

You can find APRS:

2m, 6m, 20m, 30m, CB, GRMS, TCP/IP2m, 6m, 20m, 30m, CB, GRMS, TCP/IP

National Hurricane Center, Miami FloridaNational Hurricane Center, Miami Florida

MIR, ICOM FunmobileMIR, ICOM Funmobile

VersionsVersions

Versions of APRS are available for:

• DOS, Win3.1, Win95/98/NTDOS, Win3.1, Win95/98/NT

• MacOSMacOS

• APRS PlusAPRS Plus

• JAVAJAVA

• Interactive Web BrowserInteractive Web Browser

MapsMaps

• GISGIS

• TigerTiger

• Commercial StreetCommercial Street

• DEMDEM

• ContourContour

Station StatusStation Status

• Latitude and Longitude.Latitude and Longitude.

• 200 Icons:200 Icons:

• Power Height and GainPower Height and Gain

MessagesMessages

• Messages are the only APRS packet type Messages are the only APRS packet type that is acknowledged.that is acknowledged.

• Announcements are not acknowledged; Announcements are not acknowledged; they are repeated at various intervals for they are repeated at various intervals for either 4 hours or 4 days.either 4 hours or 4 days.

• Can be sent over RF or Internet or Can be sent over RF or Internet or combination of both.combination of both.

TelemetryTelemetry

• NMEA data from GPS receiversNMEA data from GPS receivers

• Mic-Encoder packetsMic-Encoder packets

• Weather data from Peet Brothers Weather data from Peet Brothers weather stationweather station

• Voltages, Water levels, TemperaturesVoltages, Water levels, Temperatures

ObjectsObjects

• Can be created by any stationCan be created by any station

• Can be moved or updated by any Can be moved or updated by any stationstation

• Can contain additional information Can contain additional information such as course and speed, wind such as course and speed, wind speedspeed

HardwareHardware

Ordinary hardware:Ordinary hardware:

• TNC, Radio, GPS, Weather StationTNC, Radio, GPS, Weather Station

Exotic Hardware:Exotic Hardware:

• Mic-E, Trackers, DFjr, Kenwood TH-Mic-E, Trackers, DFjr, Kenwood TH-d7d7

TNCTNC

The TNC is the connection between computer and The TNC is the connection between computer and radio. radio.

• Many features:Many features:

– GPS compatibleGPS compatible

– Low power consumptionLow power consumption

– Advanced routing Advanced routing

– Multiple serial portsMultiple serial ports

– TelemetryTelemetry

RadiosRadios

• Cost between $79 and $150Cost between $79 and $150

• Data radios require DCD “true Data radios require DCD “true carrier detection” type TNCscarrier detection” type TNCs

GPSGPS

• Inexpensive - $85 to $300Inexpensive - $85 to $300

• 12 Channel Receivers common12 Channel Receivers common

• DGPS signal available from the DGPS signal available from the Coast Guard on 200khzCoast Guard on 200khz

Weather StationWeather Station

• Support for many modelsSupport for many models

– Peet, Davis, Radio Shack, HeathPeet, Davis, Radio Shack, Heath

• Peet can hook directly to TNC Peet can hook directly to TNC

• Data can be graphically trended Data can be graphically trended by APRSby APRS

MIM and MIC-EncoderMIM and MIC-Encoder

• Transmit only TNCTransmit only TNC

• GPS and analog values GPS and analog values

• Works over voice repeater or on digital Works over voice repeater or on digital channelchannel

• Voice Repeaters can mute ‘packet racket’Voice Repeaters can mute ‘packet racket’

TrackersTrackers

• Built into waterproof containersBuilt into waterproof containers

• Usually mag mount on roofUsually mag mount on roof

• Remotely administeredRemotely administered

• Run for 8 to 12 hoursRun for 8 to 12 hours

DF jrDF jr

• Plots lines right on mapsPlots lines right on maps

• 4 antenna array4 antenna array

• Resolution of 2°Resolution of 2°

• Interfaces with TNC and GPSInterfaces with TNC and GPS

Kenwood HTKenwood HT• Built in 1200 and 9k6 TNCsBuilt in 1200 and 9k6 TNCs

• 2 serial ports for GPS and Laptop2 serial ports for GPS and Laptop

• Transmit and receive APRS formatted Transmit and receive APRS formatted messagesmessages

• Shows icon, distance and bearing to 40 Shows icon, distance and bearing to 40 stations and can plot stations on GPS as stations and can plot stations on GPS as waypointswaypoints

Network InfrastructureNetwork Infrastructure

The network uses The network uses identicallyidentically named digipeaters. All named digipeaters. All APRS digipeaters are nationally coordinated on APRS digipeaters are nationally coordinated on 144.39Mhz.144.39Mhz.

Types:Types:

• RELAY - every station is a relayRELAY - every station is a relay

• WIDE - digipeater higher than 100 feet WIDE - digipeater higher than 100 feet

• WIDEn and TRACEn - special softwareWIDEn and TRACEn - special software

APRSDIGIAPRSDIGI• 286 PC becomes an APRS “super 286 PC becomes an APRS “super

digi”digi”

• On the fly compressionOn the fly compression

• WIDEn, TRACEn and call substitutionWIDEn, TRACEn and call substitution

• Remotely trend channel usageRemotely trend channel usage

TraknetTraknet• Mobiles in isolated areas can hit satellites Mobiles in isolated areas can hit satellites

with 10 watts and a 5/8 wave on 144.90with 10 watts and a 5/8 wave on 144.90

• $3 XOR chip can convert TNC to PSK at $3 XOR chip can convert TNC to PSK at the flip of a switchthe flip of a switch

• Ground stations receive data and post to Ground stations receive data and post to ARPSERVARPSERV

InternetInternet

The internet is used to interconnect cities that The internet is used to interconnect cities that are too far apart to have reliable connections are too far apart to have reliable connections via radio. Precautions have been taken to via radio. Precautions have been taken to insure non-hams cannot get on the air.insure non-hams cannot get on the air.

• JAVA Web browser: http://www.aprs.netJAVA Web browser: http://www.aprs.net

• Telnet: WWW.APRS.NET:10151Telnet: WWW.APRS.NET:10151

Time of EmergencyTime of Emergency

• An APRS field station can be assembled in An APRS field station can be assembled in minutes with any computer from a 286 to a minutes with any computer from a 286 to a Pentium. Old monochrome laptops are ideal.Pentium. Old monochrome laptops are ideal.

• ZIP LAN - many PC’s, 1 TNCZIP LAN - many PC’s, 1 TNC

• Works with any voice grade radioWorks with any voice grade radio

• Any station on the air becomes digipeaters if Any station on the air becomes digipeaters if primary digipeater is damagedprimary digipeater is damaged

National Weather ServiceNational Weather Service

Local NWS office can publish Local NWS office can publish storm warnings on a county by storm warnings on a county by county basis. Affected counties county basis. Affected counties will appear in silhouette will appear in silhouette

For additional informationFor additional information

• TAPR APRSSIG news groupTAPR APRSSIG news group

– http://www.tapr.org/tapr/html/sigs.htmlhttp://www.tapr.org/tapr/html/sigs.html

• World Wide WebWorld Wide Web

– http://www.qsl.net/kd4rdbhttp://www.qsl.net/kd4rdb

• EmailEmail

– kd4rdb@usa.netkd4rdb@usa.net