1. Automatic Packet Reporting System
APRS
Automatic Packet Reporting System
Scott Honaker – N7WLO

2. What is APRS?
Ad-hoc, connectionless network able to relay position reports and messages
No routing information is required
Packet delivery is not guaranteed
Packets contain position, status or short messages
Most stations can automatically digipeat
IGates make data available to the world
Invented by Bob Bruninga
Similar hardware requirements to packet radio but easier to implement
Basic capabilities provide position reports and short messages
IGates extend APRS functionality incredibly
N7WLO

3. APRS Use Originally intended for events
Provides basic location and message handling
Can communicate between base, mobile and portable stations
Allows assets to be plotted on map whether moving or fixed in near real-time
Simplifies deployment
Very simple implementation
There is Base (Radio/TNC), Mobile (D700) and Portable (D7) capability
Bob Bruninga is disappointed at the penetration of APRS radios (Kenwood) and has developed a broader solution with APRStt
N7WLO

4. Other APRS Uses Web page eliminates “Where are you” cell phone calls
SAR/EOC – Many now have APRS capability because it is nearly custom tailored
Messaging – Ability to reach someone live
– Can send via an IGate
Weather – Current weather reports available from connected weather stations
What the #1 cell phone call – Where are you?
King County Red Cross has 2 Kenwood D700s in their van
Seeing someone on the move means they’re likely on the radio somewhere but where?
Send a short APRS message to have them tune a machine – D700s with voice synthesizers announce new messages
access anywhere near an IGate – W2UZ confirms receipt
Peet Brothers, Davis, Radio Shack and other weather stations are supported
Historical weather data is displayed on Findu.com
N7WLO

5. APRS Uses - Continued
Security – Can send emergency message when broken down
Tracking – Use like a low-jack system
Direction finding – Several packages support DF capabilities by triangulation with multiple stations simultaneously
Extra Field Day points – post your score
Anything you can think of…
There are multiple message types and urgencies allowing everyone to be notified in an emergency
Messages are generally announced in software – emergencies have a more urgent announcement
It is possible to display current position and previous track on Findu and most software
APRSDOS (unfortunately) has the best DF capability for both omnidirectional and true DF stations with DFjr, etc.
100 Bonus points on Field Day for demonstrating “non-traditional modes”
You can use APRS messages to post your scores live on the web and club members can check Findu from home
N7WLO

6. How to connect to APRS http://map.findu.com/callsign
2m nationwide on MHz
With DOSAPRS, WinAPRS, MacAPRS, etc
HF on MHz LSB
Winlink 2000 (HF )
Satellite via PCSat or International Space Station (ISS)
Via Internet, 2m, HF or satellite
The FindU server is available to EVERYONE with an Internet connection – not just hams
HF requires an HF modem with Pactor
N7WLO

7. APRS Network APRS Station Types Basic – Transmit and receive
Tracker – Transmit only
RELAY – Provide basic digipeating
WIDE – Dedicated digipeaters with specific coverage areas
IGate – Internet gateways to repeat APRS packets to servers on the Internet
Trackers available from Tigertronics.com or Byononics.com (TinyTrak II)
Anyone can/should be RELAY or IGate but WIDE coverage areas shouldn’t overlap significantly
N7WLO

8. WIDE Digipeaterand IGATE
APRS Network Diagram
Tracker
RELAY Digipeater
Internet
Notice that tracker is transmit-only
IGate traffic is bi-directional – messages go both ways but position data generally only goes TO the Internet
It is possible to force packets OUT an IGate to the RF network by establishing a connection with a local user (send a message)
Routing through an IGate via TCP/IP allows traveling beyond RF network range and still appearing on home network
WIDE Digipeaterand IGATE
N7WLO

9. APRS on the Internet FINDU Server APRSServe WU2Z Mail Server IGate
You can connect to the APRS servers on the Internet and get an APRS stream fed directly from them for virtually the whole world. Be prepared to get bombarded with reports.
IGate
IGate
User on map.findu.com
user
N7WLO

10. APRS Routing NWAPRS Default – RELAY,WIDE3-3
One generic digipeater hop and 3 WIDE
Covers area with good WIDE support
Good coverage with minimal traffic
Little Infrastructure – RELAY, RELAY,WIDE
Uses two generic digipeaters to get to WIDE
Fixed Station – N7WLO-0,WIDE3-3
Minimizes traffic if path known
Everyone should (RELAY) digipeat but WIDE coverage areas should not overlap
For fixed stations, the best routes to the WIDE digi or IGate can be entered to minimize network traffic
The D700 beeps and displays “MY POS” when it hears itself digipeated so you know you’re in the network
When traveling in Bellevue/Redmond there are so many digipeaters that you are bombarded with beeps every x minutes
RELAY,RELAY,RELAY would keep those guys plugged up forever
RELAY stations remove the RELAY from the route after they digi so it will only be digipeated again by a WIDE
WIDE digipeaters decrement the hop count each time until 0 – WIDE3-3 becomes WIDE3-2 after first hop, then WIDE3-1, then no more hops
You can look at your path on Findu or another machine to see how many hops it took to get there
N7WLO

11. APRS Naming Callsign-SSID Tactical Callsigns
N7WLO-7 is car with Kenwood TH-D700A
N7WLO is home station
N7WLO-8 is boat
Tactical Callsigns
CAMANO, SKAGIT, SEATAC, MV911,MSEOC
More informative
Callsign included in status text
Callsign-SSID is most common for mobile and part-time stations
Tactical calls are generally only for full-time or special purpose stations
N7WLO

12. Secondary Station Ids - SSID
Symbol
NWAPRS Station Type -0
Dot
Home Station -1
Ambulance
Home PBBS -2
Bus -3
Firetruck -4
Bicycle -5
Yacht -6
Helicopter -7
Aircraft
TH-D7/D700 Station -8
Ship
Secondary Automobile -9
Car
Primary Automobile
-10
Motorcycle
Primary WIDE
-11
Balloons
Secondary WIDE
-12
Jeep
-13 RV
-14
Truck
-15
Van
TCPIP Only
The symbols were created in APRSDOS by Bob Bruninga
The NWAPRS group modified some of their meanings for the local network - None of these are required, just convention
At first the -7 for a Kenwood station seemed a bit arrogant (see my cool new radio) but it does have a use
-7 tells you that although mobile, they have messaging capability
They can also see other station locations, etc.
Trackers have no displays
N7WLO

13. Typical APRS Station 2m FM Radio
Units with packet data ports are more reliable
TNC – Kantronics KPC-3+ is the standard
GPS with NMEA support
Computer – Most anything
Software – For nearly any platform
6-pin data ports have no volume controls – just line level in and out – very consistent
KPC-3+ has GPS port in and APRS software for digipeating internal – no computer required to digipeat
Garmin GPS units are well supported (cables, software and waypoint feature on Kenwood units) and inexpensive
GPS not required for fixed station operation – just enter position manually
Virtually computer with a serial port will work
N7WLO

14. APRS Station Diagram GPS-Optional
TNC Cable – Unique to Radio/TNC Combination
RS-232 Serial Cable
An APRS station will have all these elements in some form
GPS is not required for fixed station
2m Radio
VHF TNC - like Kantronics KPC-3
Computer running APRS Software
N7WLO

15. Minimal APRS Station 2m FM Radio Windows computer with a sound card
AGW Packet Engine (software TNC)
AGW-Compatible software (like APRSPoint)
Optional GPS – not required for fixed station operation
A laptop and HT can work well
A 2m HT with a laptop running AGW packet engine and APRSPoint can be a digipeater
It has the radio, the TNC functions are done in software, and APRSPoint provides the APRS functionality complete with maps
N7WLO

16. Soundcard TNC Interfacing
This is the fully isolated Rascal interface from
This uses isolation transformers in the audio leads to/from the computer and an optoisolator in the PTT line
It assumes a DB-9 serial connector to 6-pin mini-DIN “data jack” on the radio
You can use the RigBlaster or Rascal to perform these functions or simply build an interface
N7WLO

17. Simplified Soundcard Interfacing
This diagram only covers the PTT line
It allows for both RTS and DTR switching (the two options)
It can be built entirely inside a DB-9 or DB-25 hood
The computer line-in connects to the radio out and vice versa, with or without an isolation transformer
N7WLO

18. Dedicated APRS Stations
Kenwood TH-D7A/G
Dual Band HT with internal TNC
Includes APRS software internally
All position/message functions available
Jacks for PC/Laptop and GPS input/output
Kenwood TH-D700A/G
50w Dual Band Mobile with internal TNC
Adds digipeater and other features to TH-D7
Voice synthesizer option
These radios have better APRS support than many dedicated systems – and they’re good dual band radios
Internal TNC can be used tied to a computer and software like APRSPoint or stand-alone
D7 has stereo submini serial connection and D700 has plain DB-9
Positions can be manually entered or via GPS with connector on radio (stereo submini provides RX/TX/GND)
Both units have position memories to memorize common locations without using GPS (D7 has 3, D700 has 10)
Both units have multiple status message memories
Messages can be entered through keypad or computer
Messages can be read on screen – small icon shows messages waiting
Both units show distance and bearing to station as well as its course and speed
Both units can sent received stations to Garmin GPS units as waypoints to be displayed on screen
D700 can digipeat
D700 has optional voice synthesizer ($40) to announce incoming messages
N7WLO

19. Kenwood APRS Radios
N7WLO

20. Kenwood D7 and Garmin eTrex
The Kenwood TH-D7A/G can send received station data to the Garmin GPS units as waypoints automatically.
If the GPS has basemaps, the stations will actually appear on the GPS map screen.
This screen shows KD7NM-9, N0FPF-14, KB7ILD-9 and NS7C-9 (from north to south).
This also means you can plot courses to them, get distance and bearing, etc.
The TH-D7 will also show distance and bearing for received stations.
This TH-D7 shows KB7ILD-9 at 0.0 miles east in grid CN87WP.
Newer Garmin GPS units have faster processors and can redraw a busy screen faster.
N7WLO

21. APRS Map from APRSPoint
This is after a couple hours in the Puget Sound area
Mobile station WA7RVV-15 data is displayed
Weather station AB7Y data is displayed
N7WLO

22. APRSPoint Detailed Map
Zooming in reveals street level detail (more available)
This shot of Mount Vernon shows the Skagit digi (lower right) and Mount Vernon EOC/911 center upper right
Skagit Count EOC information is on the left with callsign/contact info
N7HPE-8 is a powerboat named “Nereid V” displaying his web site info
N7WLO

23. APRS Position on FindU.com
N7WLO

24. APRS Messages on FindU.com
David uses messaging often
Red is sent messages, green is received
This represents a little more than a week
Most are “what are you doing?” or “call me on…”
N7WLO

25. APRS Weather in FindU.com
This shows 5 day trend
Day night temperature and wind changes are clearly visible
The last few days have been cloudy so the temperature change day/night hasn’t been as severe as the previous sunny days
N7WLO

26. APRS Tracking on FindU.com
There are a number of tracking displays that allow setting a start time and a geographic region to look at
There are also multiple line styles
This shows each position report individually – good for testing coverage
Other displays show a shaded line with the route
N7WLO

27. APRS Technologies MIC-E (Mike Encoder) APRStt (APRS Touch Tone)
Short (~100mS) APRS burst at the beginning of voice transmissions
Provides APRS support through voice repeaters
Available in Kenwood D7/D700
Rarely used
APRStt (APRS Touch Tone)
Latest from Bob Bruninga
Make APRS available on ANY radio with DTMF
MIC-E was available as separate unit from TAPR but has been discontinued
APRStt is currently only available in DOSAPRS with external DTMF decoder he expects Windows guys will make it work with soundcard
Has short data entry – most commands are less than 8 characters
DTMF autodial memories can be used for common functions (basic ID)
Allows entering Lat/lon minutes/seconds only (digi knows degrees)
N7WLO

28. APRS via Satellites Satellite Downlink Uplink Routing ISS 145.800
RS0ISS,SGATE,Wide
PCSAT-A
W3ADO-1,SGATE,Wide
PCSAT-B
N/A
UO-22 (9600 baud)
UOSATS
All satellites gateway to the Internet so traffic can be seen on Findu.com
Passes are short so messages would be difficult
Beaconing often would likely be necessary to insure getting in during a pass
Footprint is large so even southern Alaska and the panhandle would be covered via IGates in lower 48
N7WLO

29. Satellite Tracking with a D700
N7WLO

30. Tigertronics TigerTrak
APRS Trackers
Tigertronics TigerTrak
Basic location data
Balloon experiments (with altitude profiles)
Telemetry – River levels in Lewis County
HamHUD
The basic tracker is transmit only – like the TigerTrack and TinyTrak
The TigerTrak TM-1 is just a tracker and the TM-1+ includes telemetry
The TinyTrak II runs $30 as a complete kit (minus enclosure) and supports “Smart Beaconing”
The KPC-3 Plus is a true TNC that can digipeat standalone (no computer) and has GPS input
The HamHUD is a TNC with display for mobile use – sold as a kit only
Kantronics KPC-3 Plus
Byonics TinyTrak II
N7WLO

31. SAR/EOC Use of APRS “Real-time” tracking of assets
GPS and radio standard equipment
APRS and voice available with D7
All other stations visible on GPS displays
APRStt will provide access for everyone else
Messaging to/from units with D7
Message traffic and positions logged
Messages/positions available on Internet
available for stations via IGate
A GPS and radio are standard equipment for all participants
A Kenwood D7 tied to a GPS provides maximum capability –
Voice and data simultaneously (true dual VFO)
Messaging in/out to any other messaging capable station
(outbound) support via IGate
All message traffic and position data are logged with times for post-mortem reports
Other APRS stations appear on Garmin GPS screens as waypoints so everyone has tactical view
N7WLO

32. APRS Software Platforms
DOSAPRS
WinAPRS/APRS+SA/APRSPoint/UI-View
MacAPRS
PocketAPRS (Palm devices)
APRSce (Windows CE devices)
Xastir (Linux)
has TNC (and MP3 player) for Palm devices
Walmart was selling Handspring Visors for under $100 and GPS units for $110
There is a GPS back for Compaq iPaq as well
N7WLO

33. Windows Software WinAPRS APRS+SA APRSPoint UI-View
Oldest, feature-rich, confusing interface
APRS+SA
Good features, Street Atlas maps, two programs
APRSPoint
Limited features, cleanest interface, no better maps
UI-View
Good features, must create maps
WinAPRS is the original Windows package and has more features than any – if you can find them
WinAPRS uses the free linedraw maps (bad) or Precision Maps plug-in
APRS+SA was the second package available as an application that runs along side Street Atlas
APRSPoint is the newest so it has the fewest features at this point, although it is under active development
APRSPoint is the simplest to use and get running with very nice MapPoint maps (only MapPoint includes Canada)
UI-View has very good features but you create maps by cutting them out of other software and telling UI-View the lan/lon of range the map. There’s no Zoom feature (load a different map) but it does allow ANY kind of map (topo maps from a scanner or TopoUSA, etc.)
N7WLO

34. APRS Resources map.findu.com www.TAPR.org www.NWAPRS.org
Map.FindU.com/callsign provides the basic service to everyone
TAPR has info on all digital modes
NWAPRS has a bunch of Puget Sound and extended area APRS info
APRSPoint.com is the release point for APRSPoint
has info on AGW packet engine (Soundcard TNC)
is the release point for UI-View
N7WLO

35. Manufacturer Links www.Kantronics.com TNCs – KPC-3+
Soundcard interfaces, trackers and GPSes
TinyTrack II interface
HamHUD device in development
TNCs, cables and interfaces
Rascal soundcard interface
RigBlaster interfaces
Great deals on GPS units
This list is not exhaustive but good places to start for info
N7WLO