By Dave AD7DB

Revised March 17, 2004

What can you do with APRS?
APRS is a system of combining ham radio, GPS receivers, and digital maps to locate and track other similarly equipped stations. It adds capability for public service work and logistics, and just plain fun. Some of the possibilities are:
You can use ham radio and APRS to track positions of a car, truck, van, big rig, boat, aircraft, weather balloons, parade float or unit, person on foot, person on bicycle, race participants, automatic trackers, tornadoes, Search and Rescue teams, animals, portable or rover stations, satellites, Joe Ham's House, earthquake epicenters, disaster boundaries, tornado path, forest fires, crash site, road closures, traffic accidents, race checkpoints, aid stations, command posts, evacuation centers, emergency shelters, repeater sites, waypoints, weather stations, transmitter hunting, messages, bulletins, and much more......
  • Track moving vehicles:
    • Car, truck, van, big rig, boat, aircraft, weather balloons, nearly anything.
    • Station trail of where he's been.
    • Who is in a particular area right now.
    • Who is also nearby to assist.
  • Track other moving things:
    • Parade float or unit.
    • Person on foot.
    • Person on bicycle.
    • Race participants.
    • Automatic trackers temporarily placed or carried aboard a vehicle.
    • Tornadoes (as reported).
    • Search and Rescue teams.
    • Animal tracking.
    • Portable or rover ham station subject to relocation.
  • Plot fixed locations:
    • Joe Ham's House (plenty of them!).
    • Earthquake epicenters.
    • Disaster boundaries: tornado path, forest fires.
    • Crash site.
    • Road closures.
    • Traffic accidents.
    • Race checkpoints.
    • Aid stations.
    • Command posts.
    • Evacuation centers.
    • Emergency shelters.
    • Repeater sites.
    • General-use waypoints.
  • Automated weather stations.
  • Bearing and range info for live satellite passes.
  • Coordinated transmitter hunting.
  • Send and receive messages.
  • Send bulletins
  • Send outbound email.
And much more!

Moving stations usually use a GPS receiver to obtain their location so the coordinates can be sent out. Fixed or other stations don't need a GPS as long as the location is already known.

Before we go any further, I'd better make mention that
APRS is a registered trademark ® ™ of Bob Bruniga, WB4APR.
Here is the customary link to Bob's own APRS page, where you can see how he defines the acronym. (ARRL and TAPR have different opinions.)

"Canst thou send lightnings, that they may go and say unto thee, Here we are?" Job 38:35

What's this page for?

Yes, there's dozens of other APRS pages around. I won't even try to compete with any, like there's a need to "compete." The purpose of this page is to list my own experiences with APRS. As with all of my pages, if even one other person this year is helped by it, then it'll all have been worthwhile.

I am at this point (early 2002) getting more interested in APRS and becoming active in it sometime soon. I've attended various APRS tech sessions at ham conventions. I have a bunch of older packet gear gathering dust since I stopped using it about 10 years ago. I bought a portable GPS unit for 2/3rds OFF on a closeout. I still have various odd VHF radios around, any of which could be put to use. So all I really need to do is set up something that'll put me on the map.

The ancient packet gear from the 1980s consists of a PK-232, and an MFJ-1270. Neither of them incorporate modern APRS protocols, so a firmware EPROM upgrade is probably going to be needed if I want to use them for trackers or other serious uses.

There are other things I can do, such as buy (yes, I used that 'B' word) equipment such as one of the newer Kenwood APRS radios: the TM-D700, or the TH-D7A(G).

You can certainly do some impressive things with these units. Here is an example of tracking satellites in real time, with lots of information displayed right up front.

I don't really want to buy yet another mobile rig, and while an HT may be quite portable I'm not sure yet if I'd use it enough to justify buying another one. I have 3 HTs already, and the last one I didn't really need, but it was a store closeout deal that it would have been foolish to pass up. Have to wait and assess the situation some more.

I decided to go for the Kenwood D7A. See my notes over on the Kenwood D7A(G) page.
It's amazing what some other APRS pages can't get straight, even though we know what they're talking about.

The acronym APRS stands for:

A. Amateur Packet Reporting System
B. Amateur Position Reporting System
C. Automatic Packet Reporting System
D. Automatic Position Reporting System

The proper answer: D. It's Automatic Position Reporting System. Yes, it's done by Amateur Radio, yes it does use packet mode, but that's the proper wording.

What sort of things can we see right now?

I'm going to use a couple of unsuspecting guinea pigs because: A) they're already active on APRS, and B) they tend to get around quite a bit, so you'll never know where they might be until you check.

K5DUG is Doug. He's a trucker who travels all over the place.

VE6TG is Tom, who's also a trucker. He's from Canada but get around the U.S. quite a lot.

I've talked to both of them a number of times now on 40 meter phone. They can often be found on the 3905 Century Club nets. There is an award you can get for working them in 13 different states or provinces.

Let's see where they are.

I'll be using links to some of the following sites:
[Site 1] FindU.com is the premier site for tracking APRS stations.
[Site 2] Aprs-Is.net has better maps and icons but loads slower.
[Site 3] AprsWorld.com has its own system.

Inportant note! FindU reports (August 2002) that Mapblast.com has changed how their maps are accessed. Thus, some of the mapping features are out of order until further notice. (See what happens when we depend too much on somebody else's software?)
What this is: Doug: Tom: Me: Track my Truck!
All of their various APRS SSIDs. K5DUG
[Site 1]
[Site 1]
AD7DB. I'll be appearing here from time to time.
Check here for the current SSIDs I am using: [Site 1]
On some multi-day activities I plan to use SSID -7 for the outbound leg and -8 for the return trip. This way we can see if making any parameter changes improved coverage in some of the known crummy spots. (It's going to complicate these links a little bit, yes.)
Where they are right now (or, whenever they were last heard from). [Site 1] [Site 2] [Site 1] [Site 2] [Site 1] [Site 2]
Track of where they were recently seen! You can see that they both cover a lot of territory. Site 1: (Zoom1, Zoom2)
Site 2: 1 6 24 week ago.
Site 1: Zoom1, Zoom2
Site 2: 1 6 24 week ago.
Site 1: Zoom1, Zoom2
Site 2: 1 6 24 week ago.
Who else is nearby? We can see if any other stations are shadowing them. [Site 1] [Site 2] [Site 1] [Site 2] Site 1: [Latest] [home] [work]
Site 2: [Latest] [home] [work]
Messages sent to/from them over APRS. Doug Tom Dave
Now we're seeing some cool images. This is the plot placed on top of the regional weather radar image. See if one of these guys is trying to drive right into a storm right now! Doug (Zoom1, Zoom2) Tom (Zoom1, Zoom2) Dave (Zoom1, Zoom2)
The weather in the areas they are currently in. (I live near Van Nuys Airport (VNY), and work not far from LAX.) Doug Tom Dave [VNY] [LAX]
Plotted points showing all of their respective APRS stations in the continental U.S. Doug Tom Dave

Here are some other APRS related things of certain other areas I sometimes visit:
Location: Local Stations: Radar:
Home QTH in Van Nuys CA (grid DM04se). Local Stations near my house. Radar Image of this area.
HRO in Burbank (who's hanging around the candy store?) Local Stations Radar Image
HRO in Anaheim (another candy store) Local Stations Radar Image
Juns in Culver City (yet another candy store) Local Stations Radar Image
AES in Las Vegas (the real reason you go there) Local Stations Radar Image
The NNRC remote ham shack (somewhere around DM14cr) Local Stations (not that many nearby, most are west of there in Lancaster). Radar Image courtesy of Edwards Air Force Base.
Yucca Valley and Twentynine Palms area Local Stations Radar Image. The default is not too useful for this area, so here's the Edwards radar which covers it a little better.
Blythe Local Stations are all down along the Colorado River, it seems. Radar Image from Yuma, serves well enough.
Phoenix Local Stations (centered on the general distribution in PHX metro area). Radar Image
Provo Local Stations Radar Image
Yellowstone National Park Local Stations Probably very seasonal, check in the summertime. Also, maybe a lack of digipeaters prevents any reports from getting out. Radar Image from southern Idaho, best we can do.
Grand Canyon National Park Local Stations Radar Image
Yosemite National Park Local Stations Radar Image

And still others to look at. Some of these people I know; others are just calls that I noticed tend to get around quite a bit. And there are various other frequently updated objects to track, too.

Station: Where Now: Recent Track: Nearby Stations: Radar: Messages:
K6TVI Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
AC3X Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
KE6PCV Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
KB6OOC Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
W6DBM Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
KG6FYB Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
N6NHJ Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
KC6BLF Cal-Net Latest Position Recent [Site 1] [Site 2] Radar Messages
N4UOG long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KF4FLE long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KB3HVP long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KA0SAB long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
N7BD long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KD5XB long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KC5BPQ long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
AE9ZH long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
KJ9AY long haul Latest Position Recent [Site 1] [Site 2] Radar Messages
NB6N Calif. Latest Position Recent [Site 1] [Site 2] Radar Messages
W6MAF Calif. Latest Position Recent [Site 1] [Site 2] Radar Messages
KD7JNY Phoenix Latest Position Recent [Site 1] [Site 2] Radar Messages
N7ZEV Vegas Latest Position Recent [Site 1] [Site 2] Radar Messages
N8RRL Vegas Latest Position Recent [Site 1] [Site 2] Radar Messages
KD7ODD Vegas Latest Position Recent [Site 1] [Site 2] Radar Messages
International Space Station Latest Position Recent [Site 1] [Site 2]   Messages
PC Sat Latest Position Recent [Site 1] [Site 2]   Messages
AO-27 Latest Position Recent [Site 1] [Site 2]   Messages
RS-15 Latest Position Recent [Site 1] [Site 2]   Messages

Live JavaAPRS Maps

Another source of high quality live APRS maps is at www.aprs-is.net, by Peter Loveall, AE5PL. This page uses Java applets and high quality Microsoft Expedia maps for a really cool live display. The stations show their different icons much the way that many APRS users see it. The only problem with these maps is that the screens take longer to load, and you have to wait for the stations to show up.

Here's the map centered on the San Fernando Valley.

Here's my last reported location. You can scroll around and zoom in and out, too.

Old-Style Live JavaAPRS Maps

The guy who used to do the live Java-based map displays at www.aprs.net isn't doing them anymore (see for yourself).

AE5PL, however, is continuing to provide these displays. The Java maps are very crude, but they do display live data. The old DOS maps sure leave a lot to be desired. You can see the data on good maps at www.aprs-is.net. The same information is also at www.findu.com, but you don't see any special icons there.

Click here to go to a live Java APRS map. You will probably want to select a different map for your preferred region, then zoom in to see it better.

Other APRS sources:

Southern California APRS information. This includes recommended settings for best results.
Map of Hops Needed before reaching an I-Gate. This map, generated by Jim KB0THN, shows that throughout most of Southern California, all you generally need for your digipeater path is WIDE2-2, or RELAY,WIDE2-2. Note the dead zones up the Eastern Sierra and in some of the desert and mountain areas.
The Questionable Web Page.
Northwest APRS Group.

What SSIDs should be used for APRS?

This is a chart showing what SSIDs that people (around here anyway) seem to be using for APRS.
Object/SSID012 34 567 89101112 131415
Car2_______ _1_____1
Jeep________ _2______
Truck_1______ ______2_
Big rig1_______ ______1_
Weather2___11__ ________
House3_1_____ _1______
Wide Digi__1__1__ __11____
I-Gate___1____ ________
X_11_____ ________
(Blank)__1_____ _1__1_1_
Others3_______ ________

I made up this chart based on data recorded during some weekend trips. (The data is over at my Kenwood D7A page.) It is definitely not exhaustive and may not completely reflect what's in common use in this area.

It would seem that some of these stations chose their SSIDs based on a now-obsolete standard that used the SSID itself to determine what icon would be displayed:

-0  Dot
-1  Ambulance
-2  Bus
-3  FireTruck
-4  Bike
-5  Yacht (sail)
-6  HELO
-7  Aircraft
-8  Ships (power)
-9  Car
-10  Motorcycle (Was a satellite in older versions)
-11  Balloons
-12  Jeep
-13  Rv
-14  Truck
-15  Van

Now that you can use any of a couple of hundred icons and use any SSID you want, that old SSID standard does not need to be followed, and it would seem that a number of stations are going that route.

I posted this as an inquiry on the APRS mailing list and got some answers. Basically, it all depends on what's being done by other stations in your area, and even then it's not critical.
You can use any SSID you want to, although choosing an appropriate symbol is highly recommended.

As for me, I'm presently going with a suggestion that the NW APRS group made:

CALLSIGN (and no SSID) = Your primary home station
CALLSIGN-1 = Your primary home station PBBS (generally not used for APRS)
CALLSIGN-2 = Not assigned, ok for any use
CALLSIGN-3 = Not assigned, ok for any use
CALLSIGN-4 = Not assigned, ok for any use
CALLSIGN-5 = Not assigned, ok for any use
CALLSIGN-6 = Not assigned, ok for any use
CALLSIGN-7 = Assigned to either TH-D7A or TM-D700 radios, to let other users know that one liners may be sent, but not to exceed with long messages that cannot be processed.
CALLSIGN-8 = Secondary SSID for a mobile tracker or mobile station
CALLSIGN-9 = Primary SSID for a mobile tracker or mobile station
CALLSIGN-10 = Primary SSID for a WIDE digipeater
CALLSIGN-11 = Primary SSID for Balloons, or Secondary SSID for Wide digipeaters
CALLSIGN-12 = Secondary SSID for mobile/portable station and Wide digipeaters
CALLSIGN-13 = Not assigned, ok for any use
CALLSIGN-14 = Not assigned, ok for any use
CALLSIGN-15 = Primary TCPIP connection only, no radio connected

Around here anyway, nobody's paying much attention to that plan, as you can see.

Since I am using a Kenwood D7A, I am using AD7DB-7 for most of my operations in order to (hopefully) let other stations know that there is a 45 character limit on messages sent to me. A similar limitation exists for Kenwood D700 users. There is an APRS symbol for Kenwood, but I'd rather use a vehicle icon if that's what I'm doing.

I moved all my stuff about the D7A to a new page.
Go to my Kenwood D7A(G) Page.

Return to AD7DB Main Page.

Dave Bartholomew
Copyright © 2003 David G. Bartholomew, AD7DB.
The contents of these pages do not necessarily reflect the opinions of my Internet provider, my page host (QSL.net), my employer, nor anyone else.
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