Automatic Position Reporting System

1
Automatic Position Reporting System

• A Basic Overview
• Gene Brewer, KI6LO

ki6lo-9 (mobile tracker) ki6lo-10 (fixed
relay) ki6lo-15 (TH-D7A portable) ki6lo_at_radioroom.
org ki6lo_at_arrl.net 446-1315
2
Foreword

• For this brief, it is assumed that
• Hams experiment, tinker and like to build radio
  things
• APRS is no exception
• Most likely everything you need WILL NOT be
  available off the shelf
• You are interested in APRS and have or will get
  the needed equipment.
• if so, it is up to you to learn how to put it all
  together and use it
• Its your equipment, so be careful and dont blow
  it up..
• I make no claims to effectiveness or correctness
  of the information provided but I believe it to
  be accurate as possible.
• You know your capabilities better than anyone
  else SO..
• if you dont know HOW-TO do something - by all
  means, ask questions and learn.
• Someone else probably has already been there!
• and lastly, you got into amateur radio to have
  fun
• So lets get started learning about APRS.

3
Credits and Sources

• Websites
• web.usna.navy.mil/bruninga/
• www.tapr.org
• www.eskimo.com/archer/
• www.byonics.com
• www.theworks.com/wa6ylb
• www.findu.com
• www.winaprs.org
• Various ARRL publications on APRS and Packet
  radio

4
APRS 101

• Objective When we complete this brief you will
  actually be able to spell APRS without looking!!!

5
History of APRS

• APRS was originally developed in late 70s and
  early 80s by Bob Bruninga, WB4APR
• Professor at the US Naval Academy
• bruninga_at_nadn.navy.mil
• http//web.usna.navy.mil/bruninga/aprs.html
• APRS was developed for tracking and digital
  communications with mobile GPS equipped stations
  with two-way radio.
• APRS has been maturing over the last 20 years
  into what we are using today.

6
What is APRS?

• APRS is a real-time tactical digital
  communications protocol
• Allows exchanging information between a large
  number of stations covering a large (local) area
  using simple hardware and software setup
• APRS is quite different from conventional packet
  radio
• although they can share hardware platforms.

7
What makes APRS and Packet different

• Integration of maps and other data displays
• The mode of network connectivity
• One-to-many protocol
• Updates everyone in real time
• Uses generic digipeating
• prior knowledge of the network is not required
• Smart digipeating
• Worldwide transparent internet backbone

8
What makes APRS and Packet different

• APRS turns a packet radio system into a real-time
  tactical communications and display system for
  emergencies and public service applications (and
  global communications).
• Normal packet radio has only shown usefulness in
  passing bulk message traffic from point to point.
  
• It has been difficult to apply conventional
  packet to real time events where information has
  a very short life time and needs to get to
  everyone.

9
APRS Network

• APRS provides universal connectivity
• Avoids the complexity and limitations of a
  connected network.
• Permits any number of stations to exchange data
  just like voice users would on a voice net.
• Any station that has information to contribute
  simply sends it, and all stations receive it and
  log it.

10
APRS Network

• Although the interfaces to the Internet make APRS
  a global communications system for live real-time
  traffic, this is not the primary objective.
• APRS protocol was designed to be optimized for
  short distance real-time crisis operations.
• The planned use of APRS in an emergency or
  special event is what drives the design of the
  APRS protocol, stations and system.

11
Conventional Packet Network Connectivity

• Packet radio functions as a connected network
• You connect to the station you want to converse
  with.
• This uses time and bandwidth for the handshaking.
• OR you broadcast a CQ using a UNPROTO message (or
  UI packet)
• UI packets are not addressed to anyone and unless
  stations are setup to monitor UI packets, nothing
  is heard (or seen)
• UI packets labeled as CQ are usually followed by
  connection request from a receiving station who
  monitored the UI packet.
• You converse with the connected station until
  done
• One of the stations issues a DISC command to
  force a disconnect of the existing connection.
• All while the connection is in existence,
  handshaking is happening.
• TNCs will send ACK/NAK as needed to keep data
  flowing properly.

12
APRS Network Connectivity

• Conversely, APRS can be referred to as a
  connectionless network
• Stations converse via the broadcast (or UI)
  packets.
• Information is encoded using the APRS Protocol
  Standard
• Station type, Positioning data, Messages and/or
  bulletins, etc. are embedded in the UI packet
• Information received by all stations who hear the
  signal
• Normal APRS system setup turns MONITOR ON
• Data is decoded from the UI packet using the same
  APRS protocol standard
• There is NO handshaking between the stations via
  the network.
• You either get it or you dont system doesnt
  ask for repeats with ACK/NAK as in standard
  packet.
• This is the price of increased throughput and
  wide distribution vs. accuracy.

13
Basic Operations

• Ok, I think I want to try APRS.
• What can I do with it?

14
Uses of APRS System

• Position reporting
• Messages
• Bulletins
• Weather reporting
• DX cluster
• Satellites
• . and the list keeps expanding almost daily
• Visit WB4APRs website for latest ideas in APRS
• I am currently investigating APRS Touchtone
  linking.
• APRS inputs via any HT using Touchtone pad
• See http//www.ew.usna.edu/bruninga/aprstt.txt

15
Uses of APRS System

• One of the greatest real-time needs is the
  tracking of key assets.
• Where is the Event Leader?
• Where are the emergency vehicles?
• Whats the weather doing around the County?
• APRS is a full featured automatic vehicle
  location and status reporting system.
• Minimal equipment is needed
• Can be temporarily installed as needed
• Small portable trackers can be moved from vehicle
  to vehicle

16
APRS Symbology

• APRS uses icons as symbology to denote station
  types, software versions and a host of other
  meanings.
• The list of what the symbols mean is very large
• Suggest that if you are serious about APRS,
  download the APRS Specification document and
  refer to it.
• APRS Protocol Specification Version 1.0.1
• ftp//ftp.tapr.org/aprssig/aprsspec/spec/aprs101/A
  PRS101.pdf - 3.2Mb
• ftp//ftp.tapr.org/aprssig/aprsspec/spec/aprs101/A
  PRS101.zip - 800Kb

17
Sample APRS Map
18
Acquiring Software

• Ok, Im getting more interested. Where can I get
  software programs and APRS maps to try out?
• I also heard someone say I could look up an APRS
  station on the web. How do I do this?

19
APRS Client Capability Chart

• Capabilities of existing APRS components
• Last update 03/01/2004 102057
• Lists hardware/software
• Compares features/prices/platforms
• http//www.eskimo.com/archer/aprs_capabilities.ht
  ml

20
APRS Software

• Most APRS software is inexpensive
• Almost all versions allow a full tryout before
  registering
• Setup parameters cannot be saved until registered
  
• Versions available for
• PC (DOS, Windows 3.1, 95, 98, ME, 2000, XP)
• Pocket PC H/PC (Windows CE)
• Palm OS handhelds
• Mac OS
• Linux machines
• Sources are on the web
• Start at http//www.winaprs.org/

21
APRS Maps

• Most software packages available today can read
  the standard APRS maps files
• Do a web search on APRS Maps
• There are several sites to download free maps
• I have downloaded and archived almost all maps
  available
• Load maps in directory /MAPS ? required by
  your APRS software and run your software
• Thats all there is to it.

22
APRS Map Coverage
23
www.findu.com

• This link allows you to locate an APRS stations
  without a radio via the internet.
• Active APRS station can be located by call,
  position, locality, etc.
• Results will show local, intermediate and wide
  area maps as well as list nearby stations and
  messages to/from stations for last 240 hours of
  activity

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www.findu.com
Search for KI6LO-10 ----- subsequent local area
map.
25
www.findu.com
A map covering a wider area
26
www.findu.com
27
System Design Ideas

• Ok, Im hooked.
• What do I need to setup my APRS station?

28
Basic System Configuration
PC
TNC
Mobile Use Only
GPS
Whats that your thinking? This looks a lot
like your packet radio setup at home What up
with that? Common hardware, thats what!!! Youve
probably already got most of the items needed for
an APRS setup right now!
XCVR
ANT
29
Basic APRS Station

• Transceiver
• Almost any 2M or 70cm handheld, mobile or base
  unit will work
• Any antenna for band being used
• High gain / directivity not require but can help
• Depends on adjacent station coverage for relays
  and digipeating
• Terminal Node Controller (TNC)
• Any TAPR TNC-2 compatible TNC will work (most all
  will)
• GPS Receiver
• Any NMEA-0183 compatible GPS will work in most
  setups
• GPS not required for fixed location only for
  mobile use
• PC, Mac or Handheld computer and applicable
  software/maps
• Misc cables and power source

30
Sample Home Station

• My current home APRS station (KI6LO-10) consists
  of
• Yaesu FT-1500M 50w 2M xcvr
• 5 element 10dBi 2M YAGI (vertical mounted)
• Kantronics KAM TNC
• TAPR TNC-2 compatible
• Hewlett Packard HP-620LX Palmtop PC
• Small Windows CE 2.0 handheld running APRS/ce
  software

31
Screen of KI6LO-10
32
Sample Mobile Tracker

• KI6LO-9 mobile tracker consists of
• Yaesu FT-1500M 50w 2M xcvr
• Byonics TinyTrak 3 APRS/GPS encoder
• Transmit only No RX decode of APRS
• Converted DeLorme Tripmate GPS
• Supplies positioning data to TT3
• MFJ Dual Band Mag Mount Ant

33
Sample Digipeater

• WA6YLB-4
• 144.39 APRS network
• Full Digipeater
• Weather station interface
• Sitting atop Government Peak
• Appx. 18 miles south of Ridgecrest, near
  Randsburg
• 3521.07N 11740.38W
• Links to W6APA, K7GIL-1, WB6ZSU-10 and KD6KQ-3 ,
  WA6YLB-5 and WA6JJA-3 providing connections to
  the San Joaquin Valley on 144.39
• Operated by WA6YLB / Byron (wa6ylb_at_theworks.com)

34
Where can you find APRS activity?

• VHF (USA) 144.390 Mhz FM simplex 1200 Baud
• UHF (USA) 445.925 Mhz FM simplex 9600 (?) Baud
• Activity in the Indian Wells Valley area uses
  144.390
• KI6LO-10 is a fulltime RELAY station (north side
  of R/C) and links fairly well to WA6YLB-4 and
  SoCAL APRS network.
• WA6YLB-4 is a fulltime digipeater on Govt Peak
  near Randsburg
• Occasionally a mobile station will pass thru the
  valley
• WA7IRW is on from time to time
• KI6LO-10 monitors activity from the coast east to
  Las Vegas, from Victorville to almost Lone Pine.
• However, there are a lot of blind spots in this
  territory.

35
Modifying Building A Visit to the Junk Box

• WHAT! You dont have a junk box.. and you call
  yourself an ham
• The Old Man would be shocked !!!!
• Bring on the Wouff Hong !!!!
• Get out the Rettysnitch !!!!

An for those who dont know about The Old Man,
the Wouff Hong and the Rettysnitch, I suggest a
visit to the ARRL Website and do a little reading.
36
Simple 2m/440 Antenna Project
A simple antenna for 2M and 440Mhz on a single
mount Omnidirectional Easy to build and
inexpensive
37
Modifying a Tripmate GPS

• Must be a Tripmate as shown
• Earthmate units will not work
• Rockwell data strings
• Easy self start mod
• forces self start without PC s/w
• www.wes.johnston.net/aprs/tripmate.htm
• Requires a 5Vdc source
• Easy to make with 3 components
• NMEA-0183 data string output
• Position and movement data
• Readily available on Ebay, etc.
• Around 30-50 used.

38
Using an Earthmate GPS

• Earthmate GPS units output Rockwell data
• This is incompatible with NMEA-0183 format use
• Easiest fix is to add the Byonics GST-1 interface
  module
• Converts Rockwell to NMEA-0183 structure
• Contact Byonics
• http//www.byonics.com/gst-1/

39
Deluo GPS

• Another possible source for a GPS device is Deluo
• They have USB and serial interface GPS units
• Get the serial type if possible
• Retail around 100 but seen them surplus for 50
  to 75
• These GPS units are referred to as GPS mouse
  because they look like a PC mouse
• No display, only cable and power/status LED
• Output data stream once powered up and synced to
  the GPS constellation
• These will probably require some tinkering to
  the interface and power to make work but they do
  work just fine.
• http//www.deluo.com

40
PC Card / CF GPS Cards

• For laptop users, consider a PC card GPS receiver
• These are available on eBay or surplus websites
  for little more than the previous 3 models
• Easier to use
• Environment
• May require outside exposure

41
Commercial Products

• Not really handy at tinkering? Dont know which
  end of a soldering iron is HOT! Got a few hundred
  bucks laying around burning a hole in your
  pocket? Get your APRS off the shelf !!

42
GPS Units

• Three highly advertised GPS brands
• Garmin
• Probably the best known with most features
• I use a Garmin eMap for personal and APRS use
• Magellan
• Popular as Garmin with lots of features too
• DeLorme
• No handheld units may require Rockwell to NMEA
  conv
• Some desirable specs to look for if shopping for
  APRS GPS unit
• NMEA-0183 data output (highly recommended)
• 12VDC powered by ext cable (necessity)
• Loadable Maps
• Easy to read displays
• Easily learned user interface

43
Byonics TinyTrak 3

• TinyTrak3 is a GPS position encoder which, when
  connected to a GPS and a radio, will transmit its
  location at an adjustable rate.
• Decodes any NMEA-0183 compatible GPS sending
  GPRMC or GPGGA sentences.
• Transmits position, altitude, speed, heading, and
  timestamp (hour/minute/seconds or
  day/hour/minute).
• TinyTrak3 is available as a kit or prebuilt.
• It is very easy to build but requires some kit
  experience.
• It is configured by connecting to a computer's
  serial port, and running a simple configuration
  tool which allows setting of all user options.
• Easy way to enter into APRS for mobile tracker
  with existing handheld and GPS
• http//www.byonics.com/tinytrak/index.html

Actual Size
44
Kenwood TM-D700A

• 2M / 440Mhz coverage
• Built In TNC and APRS software
• GPS NMEA-0183 data input port
• Allows standard packet radio service with PC
  hookup
• Allows easy entry into full fledged APRS
  activity.
• Currently priced at 500 (AES 3/2004)

45
Kenwood TH-D7A(G)

• Little brother to the TM-D700A
• 2M / 440Mhz 5W hand held
• Built In TNC and updated APRS software
• GPS NMEA-0183 data input port
• Can also perform standard packet radio service
  with a PC hookup.
• Full featured dual band handheld
• Currently priced at 350 (AES 3/2004)

46
Errata

• The typical catch-all area

47
Readings

• APRS Tracks, Maps and Mobiles A Guide to
  APRS
• Stan Horzepa, WA1LOU
• ARRL publication
• This book is a goldmine of information for the
  new APRS user
• Somewhat dated (2002) however but still very
  useful
• Basic step by step configuration of common
  software packages
• Highly recommended
• Well worth the 15 cover price

48
Readings

• APRS Moving Hams on Radio and the Internet
• New ARRL publication
• Latest book by WA1LOU
• Track moving objects on maps
• Display weather statistics and storm warnings.
• Find a hidden transmitter or jammer.
• Access the APRS network on the Internet (even
  without a radio!)
• I just ordered a copy

49
APRS websites to visit

• To start it is recommended that you visit
• www.winaprs.org
• Most APRS software can be downloaded from this
  site
• web.usna.navy.mil/bruninga/
• Bob Bruninga WA4APR is the author/inventor of
  APRS
• Lots of info and data on past, present and future
  of APRS activities
• www.tapr.org
• The Tucson Amateur packet Society (TAPR)
  developed early TNC designs and brought packet
  radio into the amateur mainstream. Lots of info
  here as well as a complete library of APRS maps.
• www.eskimo.com/archer/
• Very good comparison chart of current APRS
  hardware and software

50
Summary

• APRS is different operationally to standard
  packet
• Can use common hardware suites
• Uses a non-connected network topology
• Excels at fast paced, short range, wide area
  information dissemination in emergencies or
  special events
• Lots of software available for most platforms
• Not difficult to setup but does require a little
  tinkering
• Commercial radio/TNC combos available

51
Whats the next step???

• Its up to you!!!!
• Contact KI6LO if you have questions. I will try
  and help you or point you towards an info source.
  I am relatively new to APRS myself (about 6 month
  of use).

And I have burned myself with a soldering iron
more than once!!!!
52
Questions?