Presented by Wes Johnston, KD4RDB The APRS Network

Overview of this slide show Introduction Software and features Protocol and implementation Hardware Network

Introduction APRS 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/IP National Hurricane Center, Miami Florida MIR, ICOM Funmobile

Versions 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

Maps GISGIS TigerTiger Commercial StreetCommercial Street DEMDEM ContourContour

Station Status Latitude and Longitude.Latitude and Longitude. 200 Icons:200 Icons: Power Height and GainPower Height and Gain

Messages Messages are the only APRS packet type that is acknowledged.Messages are the only APRS packet type that is acknowledged. Announcements are not acknowledged; they are repeated at various intervals for either 4 hours or 4 days.Announcements are not acknowledged; they are repeated at various intervals for either 4 hours or 4 days. Can be sent over RF or Internet or combination of both.Can be sent over RF or Internet or combination of both.

Telemetry NMEA data from GPS receiversNMEA data from GPS receivers Mic-Encoder packetsMic-Encoder packets Weather data from Peet Brothers weather stationWeather data from Peet Brothers weather station Voltages, Water levels, TemperaturesVoltages, Water levels, Temperatures

Objects Can be created by any stationCan be created by any station Can be moved or updated by any stationCan be moved or updated by any station Can contain additional information such as course and speed, wind speedCan contain additional information such as course and speed, wind speed

Hardware Ordinary hardware: TNC, Radio, GPS, Weather StationTNC, Radio, GPS, Weather Station Exotic Hardware: Mic-E, Trackers, DFjr, Kenwood TH-d7Mic-E, Trackers, DFjr, Kenwood TH-d7

TNC The TNC is the connection between computer and radio. Many features:Many features: –GPS compatible –Low power consumption –Advanced routing –Multiple serial ports –Telemetry

Radios Cost between $79 and $150Cost between $79 and $150 Data radios require DCD “true carrier detection” type TNCsData radios require DCD “true carrier detection” type TNCs

GPS Inexpensive - $85 to $300Inexpensive - $85 to $ Channel Receivers common12 Channel Receivers common DGPS signal available from the Coast Guard on 200khzDGPS signal available from the Coast Guard on 200khz

Weather Station Support for many modelsSupport for many models –Peet, Davis, Radio Shack, Heath Peet can hook directly to TNCPeet can hook directly to TNC Data can be graphically trended by APRSData can be graphically trended by APRS

MIM and MIC-Encoder Transmit only TNCTransmit only TNC GPS and analog valuesGPS and analog values Works over voice repeater or on digital channelWorks over voice repeater or on digital channel Voice Repeaters can mute ‘packet racket’Voice Repeaters can mute ‘packet racket’

Trackers 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 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 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 messagesTransmit and receive APRS formatted messages Shows icon, distance and bearing to 40 stations and can plot stations on GPS as waypointsShows icon, distance and bearing to 40 stations and can plot stations on GPS as waypoints

Network Infrastructure The network uses identically named digipeaters. All APRS digipeaters are nationally coordinated on Mhz. Types: RELAY - every station is a relayRELAY - every station is a relay WIDE - digipeater higher than 100 feetWIDE - digipeater higher than 100 feet WIDEn and TRACEn - special softwareWIDEn and TRACEn - special software

APRSDIGI 286 PC becomes an APRS “super digi”286 PC becomes an APRS “super digi” On the fly compressionOn the fly compression WIDEn, TRACEn and call substitutionWIDEn, TRACEn and call substitution Remotely trend channel usageRemotely trend channel usage

Traknet Mobiles in isolated areas can hit satellites with 10 watts and a 5/8 wave on Mobiles in isolated areas can hit satellites with 10 watts and a 5/8 wave on $3 XOR chip can convert TNC to PSK at the flip of a switch$3 XOR chip can convert TNC to PSK at the flip of a switch Ground stations receive data and post to ARPSERVGround stations receive data and post to ARPSERV

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

Time of Emergency An APRS field station can be assembled in minutes with any computer from a 286 to a Pentium. Old monochrome laptops are ideal.An APRS field station can be assembled in minutes with any computer from a 286 to a 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 primary digipeater is damagedAny station on the air becomes digipeaters if primary digipeater is damaged

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

For additional information TAPR APRSSIG news groupTAPR APRSSIG news group – World Wide WebWorld Wide Web –