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Domain: aprsworld.net
Stories and comments across the archive that link to aprsworld.net.
Comments · 9
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RF-based location search
Here's another RF-based location search. The software is all OSS.
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Try using some APRS data
Some ham radio guys have their weather stations send the current WX conditions to the internet. Try going here and entering in your city and state into their search. From there look for stations with a blue circle with WX in the middle. Those stations send out weather data. In my case the station CW2113. Click on the date to get the raw packet. From there you can decode the data.
CW2113>APRS,TCPXX*,qAX,CW2113:@290007z4138.23N/087 49.28W_356/007g...t056P057h87b10047.DsVP
Ignore everything before the @
29 is the Day
0007z is the zulu time
4138.23N/08749.28W are the lattitude and longitude of the station
356/007g wind is from 356* at 7MPH
t056 tempature is 56*F
P057 0.57" of precip have fallen
h87 is 87% humidity
Alternatively you can buy a scanner and a TNC and listen to the packets yourself on 145.390MHz.
Some other interesting sites are jfindu and googleAPRS -
Try using some APRS data
Some ham radio guys have their weather stations send the current WX conditions to the internet. Try going here and entering in your city and state into their search. From there look for stations with a blue circle with WX in the middle. Those stations send out weather data. In my case the station CW2113. Click on the date to get the raw packet. From there you can decode the data.
CW2113>APRS,TCPXX*,qAX,CW2113:@290007z4138.23N/087 49.28W_356/007g...t056P057h87b10047.DsVP
Ignore everything before the @
29 is the Day
0007z is the zulu time
4138.23N/08749.28W are the lattitude and longitude of the station
356/007g wind is from 356* at 7MPH
t056 tempature is 56*F
P057 0.57" of precip have fallen
h87 is 87% humidity
Alternatively you can buy a scanner and a TNC and listen to the packets yourself on 145.390MHz.
Some other interesting sites are jfindu and googleAPRS -
Try using some APRS data
Some ham radio guys have their weather stations send the current WX conditions to the internet. Try going here and entering in your city and state into their search. From there look for stations with a blue circle with WX in the middle. Those stations send out weather data. In my case the station CW2113. Click on the date to get the raw packet. From there you can decode the data.
CW2113>APRS,TCPXX*,qAX,CW2113:@290007z4138.23N/087 49.28W_356/007g...t056P057h87b10047.DsVP
Ignore everything before the @
29 is the Day
0007z is the zulu time
4138.23N/08749.28W are the lattitude and longitude of the station
356/007g wind is from 356* at 7MPH
t056 tempature is 56*F
P057 0.57" of precip have fallen
h87 is 87% humidity
Alternatively you can buy a scanner and a TNC and listen to the packets yourself on 145.390MHz.
Some other interesting sites are jfindu and googleAPRS -
A few interesting things
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Re:In case of slashdot...
Great, so what you were seeing is the raw protocol data.
For examples of what gets done with it see
aprsworld, an open source site and database of APRS location-based service data generated by and for hams.
You can see google map overlays, ACME.com topo map overlays, tracking data, historical events, and also other services such as weather reports from individual weather stations. -
Ham radio text messagingThere's a couple of ham radio text messaging type things.
- One, called PSK31, uses less bandwidth than a morse code signal (31Hz), and uses a computer soundcard to audio encoding and decoding. You can read more about it here. You can talk around the world with 5 Watts on HF (high frequency, 14.070 MHz, in this case). There are other, similar, digital modes available for keyboard-to-keyboard communications (synchronous, non face-to-face) that have different radio propagation and bandwidth characteristics, as well as image transmissions modes that work on HF, which propagates world-wide, and you can read about those in the PDF presentation above as well.
- The other, APRS , uses VHF and UFH (usually 144.39 MHz in the US), and because of the shorter range, uses a store-and-forward packet technology. This mechanism is more like SMS in that it is asynchronous, non-face-to-face, and in that it uses a network of repeaters and packet forwarding systems, and message lengths are limited.
There used to be a wider ham packet network, back before the ARPANet became the Internet; this piggybacks on the technology and uses it for short message, position reporting, and weather reporting. Check out APRSWorld.net for open-source software for the network side of this. (The radio side is already taken care of in the Linux kernel, and in various Windows packages. There is also a client program called XASTIR.
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I did this last yearI did something like this last year using amateur radio's Automatic Packet Reporting system. Basically there are thousands of amateur radio operators that broadcast their GPS position. Using software I wrote along with MySQL and Mapserver I was able to create maps that showed real-life traffic flow.
You can see a sample of this type of map and learn a little bit about it at http://aprsworld.net/info/paper2002/giant-map-of-
l a.php-James Jefferson
KB0THN -
I did this last yearI did something like this last year using amateur radio's Automatic Packet Reporting system. Basically there are thousands of amateur radio operators that broadcast their GPS position. Using software I wrote along with MySQL and Mapserver I was able to create maps that showed real-life traffic flow.
You can see a sample of this type of map and learn a little bit about it at http://aprsworld.net/info/paper2002/giant-map-of-
l a.php-James Jefferson
KB0THN