So why might I want to try APRS? ...

[cmeisenzahl]

I have an Icom 2200 in the minivan, and two HTs. The Yaesu FT-270 is in the car, and The VX-3R is in my briefcase all of the time.

I've been hearing a little more about APRS, which I think is pairing-up a GPS receiver with a radio in order to regularly broadcast your position?

A few questions.
1. Why might I want to do this? Just for the technical interest? Or is there something more?
2. What additional hardware would I need to make this happen? I hear something about a GP "puck?"
3. When someone is sending their APRS info, who/what is picking up the signal and making it available to others? How does that work?


Thanks VERY much in advance!
Chris

 

[nd5y]

Check out APRS: Automatic Packet Reporting System if you haven't already.

A GPS puck is a small cheap receiver/antenna with no controls or display that only sends data to a computer or other device.

Your own receiver picks up other stations. There are also digipeaters that repeat what they hear locally and can also be connected via internet gateways.

APRS uses AX.25 packet radio in a non-connected mode. It sends UI packets. That means there is no handshaking or acknowlegement of received packets and bad packets are not retransmitted. AX.25 only works well with strong signals. There is no foreward error correction or data interleaving like other modern digital modes have. It only uses a checksum. If one bit of data is bad and the checksum doesn't match the whole packet is discarded. When you combine all that with people who don't know how to properly set their transmit deviation, and other parameters, running everything on one frequency (144.390), people running cheap beacon transmitters with no receiver, and doing other things wrong, it is a wonder it works at all.

I messed with it several years ago and gave up because I found no practical use for it and most of the packets I could hear didn't decode.

 

[AK9R]

I guess it depends on where you are and what you want to use it for.

We use APRS extensively in Central Indiana to track assets during public service events. A prime example is the Hilly Hundred bike ride in Monroe County, Indiana, held in October each year. The event uses as many as 20 SAG vehicles to patrol the course and pick up riders who are unable to continue. Each of the SAGs carries an APRS tracker. The SAG Coordinator and the amateur radio net control operator both monitor an APRS map which shows the location of each of the SAGs in near real time. This nearly eliminates voice chatter about the location of the SAGs and allows the SAG Coordinator to position the SAGs where they are most needed.

APRS is also used quite a bit by amateur balloonists to track their payloads.

And a common use for APRS that I see around here is family members keeping track of each other. I know several over-the-road truck drivers who have APRS in the vehicles. This allows their wives/girlfriends to quickly look at map to see where they are.

However, Bob Bruninga WB4APR, the developer of APRS, routinely tells us that APRS is not just for tracking. APRS can also be used to provide local information such as voice repeater frequencies, nets, meetings, hamfests, etc. This allows someone unfamiliar with the area to learn about amateur radio activities in the area.

 

[cmeisenzahl]

Helpful stuff, thanks, all.

 

[GROCKSHD]

Also check out Google Maps APRS for a live map of your area. I exclusively use APRS to create objects (ie. Traffic, Construction, Fires, Weather, etc...) for users in Hampton Roads, that way they are informed about potential Hazards or Traffic Delays.

 

[WX4JCW]

i am a trucker and use APRS, yes for tracking but also meeting fellow trucker hams on the road, i have a Kenwood, TM-D710 paired with an Avmap G5 and can see other truckers and amateurs while traveling and have made some good contacts and a few friends that way.
APRS is not just for tracking you can share weather data and Messages as well

 

[LtDoc]

Why would you want to do APRS? Lots of possible reasons. They can range from just because you can, to some particular need for tracking a particular radio/person/vehicle.
What equipment would you need to do APRS? Several possibilities there too. Very basically, APRS is packet radio with the information obtained from a GPS receiver configured in a particular format. That formatted information is then send to the radio to be transmitted. That transmitted information is then picked up/received by other stations directly, or, it is repeated through a 'digipeater', or, is translated to be sent to the internet for wider distribution.
Almost any radio can be used to transmit APRS signals. Some are much easier to connect to all the required 'gadgets' to do that, or may even have those 'gadgets' built into them. There are also 'stand-alone' transmitters that can do it, and then receiving those APRS signals is done with something else (computer and receiver with the correct programs).
I'm not familiar with your radios so can't tell you specifically what you would need to do all this. It certainly isn't that hard to do (at times), and I find it very interesting. I also use it with others for particular purposes, and to track my self. There are commercially available programs that can do all this, such as 'Delorme's programs. But it's one of those, "I did it!", thingys with APRS. It isn't going to be 'free', there will be expenses. So, think about it, read all you can find about it, think about it some more, and make up your own mind.
- 'Doc

 

[K9WG]

And for the other side of the coin, I don't use it because I don't want anyone to know if I am home or not.

 

[WX4JCW]

Position ambiguity or turn it off


---
I am here: http://maps.google.com/maps?ll=36.665570,-121.630866
Jason WX4JCW
Sent from my iPhone4 using Tapatalk