Automatic Packet/Position Reporting System (APRS)

APRSdos Documentation(APRS)

2. Within the program hit F1 to select from a number of HELP screens
3. Use the README FILE INDEX below to find detail on many APRS subjects
4. APRS commands are single KEY commands. Some bring up additional menus

SUMMARY: APRS can be summed up with two concepts, REAL-TIME PACKET TACTICAL COMMUNICATIONS and MAPS. Probably 98 % of APRS potential does not need GPS or any tracking device. Think of APRS as just a multi-user distributed packet network with a MAP display for many exciting amateur applications:

Network topology monitoring Direction Finding Weather reporting
Frequency Coordination database DX cluster monitoring HF DX plotter
AMSAT ground station tracker Satellite tracker Search & Rescue
Special event tracker/organizer Boat/mobile/RV tracker RF path estimating
Local area CHAT mode Telemetry displays Airline tracking

For the Vehicle tracking it is important to use the standard 145.79, 445.925, HF 10.1515 LSB and CB channel 29 vehicle tracking frequencies, if available. Mobile's are often XTAL controlled. See HF.HTM and UHFFREQ.HTM for freqs.

In addition to these standard APRS freqs, use APRS as a monitoring tool on all frequencies for plotting the locations of NODES, BBS's, DIGI's and other network assets which include their position in their beacons. This is an excellent Frequency Coordination tool! Each night when you secure, tune your APRS radio to a different digital frequency and see who you pick up.

DEMONSTRATIONS: First, hit the MAPS-OVERLAY-DIGIS command to see where all the existing APRS digipeaters are to see if their is activity in your area. Next, there are two important DEMO commands for past events. One loads a snapshot (nothing moves) of previous events from the BACKUP files using the FILES-LOAD command. Secondly, use the more powerful FILE-REPLAY command to replay track histories of previous events. Many past APRS events are included on the distro disk. Replay them all and use the PgUP/DN keys and HOME key to zoom in or out as the file is replayed.

DOCUMENTATION: Choose from any of the following files. These files can be read ON-LINE using the F1(HELP)-FILES command. These files are in the README subdirectory:

File name Description
INSTALL.HTM Tells you how to unzip the APRS distro disk and get started
INDEX.HTM This file. Provides an overview and INDEX to all other files
NEWNOTES.HTM Tells of important changes in the latest versions
APRS.HTM General description and overview of APRS
AIRCRAFT.HTM Using APRS from Aircraft and how to interface to ARNAV format
BBSNOTES.HTM Suggestions to BBS SYSOPS on how to use APRS
BOATS.HTM Suggested use of APRS to support the WaterWay Net
CELLULAR.HTM Using APRS for nationwide vehicle tracking via Cellular phone
DF.HTM Information on DFing and AUTOMATIC Doppler interfaces!
DEMOS.HTM A quick summary of demonstrations and replays to impress you.
DIGIS.HTM Important info on using Digipeaters
DIGITIZR.HTM Using DIGITIZERS to draw your own maps with MAPFIXER.bas prgm.
DOWNLOAD.HTM List of BBS's and FTP sites carrying APRS
PROTOCOL.HTM Info on APRS formats for setting up TNC BTexts
DXCLUSTR.HTM Info on using APRS to plot DX spots on a DX cluster frequency
GPS.HTM Interfacing GPS or LORAN to APRS or stand-alone TNC's
HF.HTM Notes on the APRS HF tracking network
HELP.HTM Describes each of the APRS commands in detail
MAPS.HTM Overview of MAP distribution and sources, experts and Elmer's
MAPMAKIN.HTM Details on the structure of an APRS map file
MAPSCD.HTM How to make maps from the USGS CD ROMS ($32 each)
MARATHON.HTM Lessons learned at the Marine Corps Marathon
METEOR.HTM How to use APRS during meteor showers
MOBILE.HTM Notes on Mobile operations with GPS
MOUSE.HTM How to use a MOUSE with APRS
OPS.HTM Suggestions on routine APRS operations
SCREEN.HTM Describes the APRS screen and display areas
SPACE.HTM Suggested use of APRS for plotting satellite packet stations
SYMBOLS.HTM A table of APRS symbols and the symbol designators
TELEMTRY.HTM Describes a SINGLE-CHIP TNC telemetry xmtr for balloons, etc..
TROUBLE.HTM Hints and ideas for troubleshooting
MICE.HTM Integrating APRS into voice repeaters
WX.HTM Info on using APRS for displaying weather information
IDEAS.HTM A file of other neat APRS ideas to encourage others to write supporting TNC and forwarding code. Programmers READ IT!
TRAKNET.HTM An idea to use the AMSAT PACSAT's for nationwide mobile comms

SETUP: First, zoom into your area of activity with the Page and HOME keys. Next set your desired digipeater path using the APRS UNPROTO command. This command needs your TNC connected before it can work. (To understand the UNPROTO concept, refer to your TNC manual). Finally, use the ALT-SETUP menu to SAVE your config file. Give your validation number when prompted and select a CONFIG file extension. Usually the default .APR.

Be sure to use the MAPS-CHANGE command to change to your regional MAPLIST .xxx file. Many states have developed their own map packages: CA, OH, AK, MO, MN, NC, etc.. (see MAPS.HTM) Non US hams can change the default map from the USA location by changing the LAT/LONG and RANGE in the first three lines of the MAPLIST.USA file.

MAPS! - Maps to the street level can be made for anywhere in the world using the map making tools provided with APRS. To see example street level maps, zoom into Idaho Falls at the 1 mile range, or either Baltimore or NewOrleans at the 4 mile scale to see maps made with a digitizer. See North Tennessee for the type of highway maps available on the USGS 2,000,000 CD ROM, or zoom into my QTH at 3909N 07636W to see the 100k CD ROM map made by KB8JXO. You can make your own maps from the directions in MAPMAKIN.HTM using a variety of techniques. You can purchase the $32 USGS CD for your area and use MK100K2a.EXE to make street level maps anywhere in your area. See MAPSCD.HTM. Or use MAPFIX.exe and a digitizer to make any map anywhere. You can even make a map using paper and a ruler and a text editor!. OR just replay a GPS track history in the MAPFIXxx.BAS program and build your own map!

APRS is now distributed in four regional versions due to the large number of maps becoming available. See MAPS.HTM for details. Look for an APRS BBS in your state for detailed local maps. If your area does not have at least the major highways on your maps. Let me know.

APRS PROTOCOL: APRS uses Unnumbered Information (UI) frames without ACKS to avoid the problems of a normal connected network. You need to understand DIGIPEATING and the UNPROTO command, since you are responsible for your own best path within the network. If you are unfamiliar with these UI terms, consult your TNC user manual. Also note that while APRS is running, it generates its own Position and Status beacons. Your TNC BText is not used until you Quit APRS; then your TNC BText is activated.

PACKET POSITIONS ON ALL FREQS: Encourage all BBS's, NODES, Servers, and other stations in your area, to place their LAT/LONG in their beacon text using the format: BT !DDMM.xxN/DDDMM.xxW/....comments. APRS will also plot the positions of stations reporting by Grid Square surrounded by brackets [FM19xy] (at the beginning of the BText only). If all packet assets get in that habit, then APRS will automatically plot a map of packet activity on any frequency! If stations will also use the Power/antenna/gain format in their BText, then effective communications ranges can also be displayed! See PROTOCOL.HTM.

STAND-ALONE-GPS-TRACKERS: Most new TNC's now include GPS commands that tell the TNC to accept GPS data on the serial port and transmit it periodically. Assembling a TNC, GPS and a radio is all that is needed to build a dedicated stand-alone tracking device. No PC nor APRS is needed on the vehicle. If you do run APRS in the mobile, see GPS.HTM for ways to interface your TNC and GPS.

MORE READING: See ARTICLES.HTM for a complete list of articles.

QST - pg 92 July, pg 11 Aug 93 QST, pg 14 Dec 94, pg 68 Oct 95 about TNC's
QEX - Feb issue, 1994 for info on interfacing GPS to packet
CQ - Packet column Dec 1993
73 - October 94 under the topic of HOMING IN. Also in Jan, Feb 95 issues
AMSAT - May 1993, AMSAT journal (but registration info is incorrect).
73 - December 1996 (8 pages)
ARRL - The ARRL now publishes a book on APRS

SEE DOWNLOAD.HTM for a list of BBS's, WWW and INTERNET sites.! Check out my LIVE APRS web site at

APRS INTERNET SPECIAL INTEREST GROUP: This internet re-mailier keeps all APRS hobbiests up to date on all the latest happenings. To subscribe, send a message to `` with the following line in the body of the message:

subscribe aprssig full_name Example: subscribe aprssig FirstName LastName

For info on APRS COORDINATORS for our area, see MAPS.HTM.

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