APRSWiki - User contributions [en]

Talk:Main Page

2007-08-31T12:07:45Z

JosephDurnal: Apologies

This page ought to at least mention what 'APRS' stands for. --[[User:ScottN1VG|ScottN1VG]] 12:05, 17 August 2007 (Pacific Daylight Time)

APRS = Automatic Packet Reporting System --[[User:JosephDurnal|JosephDurnal]] 09:39, 28 August 2007 (Pacific Daylight Time)

I'm confused - is it Packet, or Position? Earlier today I was sure it was packet, that is how it is described on http://www.ew.usna.edu/~bruninga/aprs.html, but other sources say Position. If it is really position and you know for sure, please change it back to position and cite something that confirms it. Thanks --[[User:JosephDurnal|JosephDurnal]] 12:02, 28 August 2007 (Pacific Daylight Time)

APRS was originally "Automatic Packet Reporting System" and was changed by Bob Bruninga at some point to "Position" --- and is referred to that way almost universally now. Bob's top-level web page still says "Packet", but the PDF version of the [http://www.tapr.org/aprs_working_group.html official APRS spec] calls it "Position" (even though the HTML page that <em>links</em> you to the PDF spec says "Packet"!) so that would be a pretty definitive statement that the correct name is "Position" and that there is considerable confusion and outdated web information all over the place. Bob has often regretted the name change, because it has pigeon-holed APRS as a vehicle tracking system, where it is very much more, but the name is pretty well established as "position" now. I'll go to the pages the pages where you changed "Position" to "Packet" and put them back to the way the spec is. --[[User:KM5VY|KM5VY]] 10:21, 30 August 2007 (Pacific Daylight Time)

Thanks - sorry for creating the work. I'm still pretty new to APRS, but when I made the change, I wqas pretty sure I was correct. The trouble with wikis is that some of us just think we know what we are talking about. 73 de Joe NE3R --[[User:JosephDurnal|JosephDurnal]] 05:07, 31 August 2007 (Pacific Daylight Time)

Talk:Main Page

2007-08-28T19:02:35Z

JosephDurnal:

Talk:Main Page

2007-08-28T19:02:15Z

JosephDurnal: Packet or Position?

Glossary

2007-08-28T18:02:15Z

JosephDurnal: Automated Packet Reporting System!

=== APRS Glossary ===

* [[Main_Page|APRS]]: Automated Packet Reporting System

* [[InternetSystem|APRS-IS]]: APRS-Internet System

* digi: short for "[[Digipeater|digipeater]]"

* [[Digipeater|digipeater]]: a "digital repeater," a radio transceiver (often mounted on a hill or mountain) which re-broadcasts the packets it receives over a wide area

* findu: a web site at [http://www.findu.com http://www.findu.com] which collects APRS data from APRS-IS and can answer queries on the database. Also, generically, the Internet aspect of APRS, though there are many other useful APRS sites

* gate: short for [[IGate]]

* GPS: Global Positioning System. A //GPS receiver// uses signals from satellites to determine its position. For APRS use, the GPS receiver will then send the location information to a TNC for transmission by radio

* ham: a person who uses amateur radio. The origin of the nickname is obscure

* hop: when a [[Digipeater|digipeater]] repeats a packet, it's considered a "hop." If a second digi receives the packet from the first digi and retransmits it, that counts as a second hop

* [[IGate]]: Internet Gateway, a radio and computer setup for receiving packet data via radio and sending those packets to the Internet (via [[InternetSystem|APRS-IS]])

* packet: a bundle of data (like an APRS user's call sign and location, or a weather station's report on conditions) plus a path and other information, represented as a set of bytes in a computer or transmitted via radio as a series of rapidly-changing tones

* [[Paths|path]]: a specification of the path a packet should take through the [[Digipeater|digipeater]] system. Can be explicit (using the callsigns of the intended repeaters and the ultimate destination) or symbolic, like "WIDE2-2" which [[Digipeater|digipeaters]] will interpret to mean "repeat twice."

* TNC: Terminal Node Controller. A device which can control a radio and transmit computer data (like a user's call sign and GPS position information) using a series of rapidly-changing tones

* [[VoiceAlert|Voice Alert]] is a way of setting up an APRS station to notify you if other active stations come into simplex voice range

VoiceAlert

2007-08-28T17:46:17Z

JosephDurnal: Added - No APRS Gear?

Voice Alert is quite simply setting your (Kenwood) APRS rig to PL tone squelch 100.0hz (for North America) (See notes for PL tone frequancies used in other countries) with the volume turned up to mid range.

This is particularly easy on the kenwood d700 rig since it can mute the speaker with the PL tone squelch while still receiving packets. Other rigs which use the 6 pin mini-din packet connector are also suitable for this mode because they allow the TNC to connect to the radio ahead of the PL tone decoder. The speaker jack of the radio is not a suitable connection for two reasons: 1) The audio will not be heard because a plug is plugged into the speaker jack, and 2) the PL tone decoder will prevent the TNC from decoding most packets.

'''''No digipeater should ever transmit a 100.0hz PL tone!'''''

'''''Only stations with a live operator present should transmit a PL tone of 100.0hz'''''

The concept is really simple. If there is an operator present at an aprs station, the radio should transmit a 100.0hz PL tone with each packet. Any other Voice Alert APRS station within simplex range will hear the packet and know that they are within range of another station. If one wishes to talk to the other, he simply calls on the APRS frequency using the PL tone. The idea here is to keep it short - just state the person's callsign and ask them to QSY to a voice frequency. Keep in mind that most digipeaters do not stand down for non packet signals, so it is likely that any voice traffic on the aprs frequency will end up doubling with other packets.

What makes Voice Alert so intriguing is that it allows a traveler to conveniently listen for other live stations. Can you imaging calling CQ CQ every minute on 146.52 while traveling? With the voice alert system, your aprs station's normal position beacon becomes a "sonar ping" to other nearby people.

It has also been suggested that if a non-standard PL tone were to be used, it would be like a private voice alert.

Non-standard PL tones have also been used on various digipeaters to verify local coverage areas. The trick here is to put a different PL tone on each of the local digipeaters and tune your PL tone squelch to one of them as you travel around town. You'll hear every packet the digipeater transmits and can assess the signal quality without having to take your eyes off the road.

=No APRS Gear?=
Tune your 2 meter FM transceiver to 144.39 MHz and configure encode and decode CTCSS 100 Hz. When APRS stations configured with voice alert are near, their packets will be passed to the radio's speaker, letting you know that someone is in range and probably listening. You won't know their call sign, but give a general CQ, or "calling APRS Voice Alert Stations" on the frequency to make contact, then change to another simplex frequency.

=NOTE=
The Voice Alert PL tone use in Australia (VK) is 91.5Hz

Talk:PathOverkill

2007-08-28T16:41:07Z

JosephDurnal: New page: http://www.bestbits.org/aprs/four-hop-aprs.gif is a broken link! --~~~~

http://www.bestbits.org/aprs/four-hop-aprs.gif is a broken link! --[[User:JosephDurnal|JosephDurnal]] 09:41, 28 August 2007 (Pacific Daylight Time)

Talk:Main Page

2007-08-28T16:39:04Z

JosephDurnal:

Main Page

2007-08-28T16:35:55Z

JosephDurnal: APRS Stands for Automatic Packet Reporting System

[[Image:APRS_logo.gif|APRS Logo]]

=== Automatic Packet Reporting System ===

APRS is an amateur radio based digital communications system for local, tactical, real-time exchange of information among all members of a net, including map based displays for stiuational awareness. It was developed by Bob Bruninga, [[http://www.qrz.com/wb4apr WB4APR]], who currently works at the United States Naval Academy.

== Capabilities ==
APRS is used to transmit real-time information such as messages, bulletins, announcements and the locations of any stations or objects via amateur packet radio protocols. Real-time reporting of station position for mobiles is facilitated using the Global Positioning System. APRS is capable of transmitting a wide variety of data including weather reports, short text messages, radio direction finding bearings, telemetry data, and storm forecasts. These reports can be combined with a computer and mapping software to show the transmitted data superimposed on a variety of map displays.

== Technical Information ==

In its most widely used form APRS is transported over the air using the AX.25 protocol at 1200 baud Bell 202 audio frequency-shift keying on frequencies located in the amateur 2-meter band (see [[Frequencies]]). An extensive digital repeater, or [[Digipeater|digipeater]] network provides transport for APRS packets on these frequencies. Internet gateway stations ([[IGate|i-Gates]]) connect the on-air APRS network to the APRS Internet System ([[InternetSystem|APRS-IS]]), which serves as a worldwide, high-bandwidth backbone for APRS data. Stations can tap into this stream directly. [[APRSIsDatabases|Databases]] connected to the APRS-IS allow web-based access to the data as well as more advanced data mining capabilities. A number of low-earth orbiting satellites and the International Space Station are capable of relaying APRS data.

== Topics ==

{| border="1"
|[[UpcomingEvents|Upcoming Events]]
|[[Applications|APRS Uses]]
|[[History]]
|-
|[[Introductions]]
|[[Paths|Path Settings]]
|[[Frequencies]]
|-
|[[Hardware]]
|[[Software]]
|[[Protocol]]
|-
|[[Organizations]]
|[[RelatedSystems|Related Systems]]
|[[InternetSystem|APRS Internet System (APRS-IS)]]
|-
|[[Satellites]]
|[[Glossary]]
|[[WikiUsage Contributing to this Wiki]]
|}

==External links==
*[[http://www.aprstv.com APRSTV]] APRS related video podcast.
*[[http://www.ew.usna.edu/~bruninga/aprs.html WB4APR web site]]
*[[http://www.findu.com www.findu.com]] Web-based access to worldwide APRS real-time data
*[[http://www.openaprs.net OpenAPRS]] Web-based APRS real-time data using Google Earth Maps
*[[http://aprs.he.fi aprs.he.fi]] Web-based APRS data using Google Maps and Earth, updates automatically in real-time
*[[http://aprs.va3tk.com VA3TK's APRS Server]] Canadian Web-based APRS Server
*[[http://f5vag.eu F5VAG's APRS Server]] French Web-based APRS Server
*[[http://www.APRSworld.net APRS World]] Open Source web-based APRS database
*[[http://www.tapr.org/aprs_working_group.html APRS Specification]] Official APRS specification document
*[[http://www.nwaprs.info Pacific Northwest APRS Homepage]] - [[http://wiki.ampr2.net/nwaprs/ NWAPRS alternate Wiki]]
*[[http://www.wulfden.org/APRSQuery.shtml APRS Query Page]] N1BQ's HTML Forms based front end to the FINDU database
*[[http://www.cwop.net www.cwop.net]] APRSWXNET/Citizen Weather Observer Program (CWOP)
*[[http://groups.yahoo.com/group/javaprssrvr/ JavAPRSSrvr Yahoo Group]] This group is for users of the APRS-IS server software, javAPRSSrvr.
*[[http://groups.yahoo.com/group/uidigi/ UIDigi Yahoo Group]] A replacement for TNC2 firmware to upgrade older TNC's to APRS.
*[[http://www.jfindu.net/ JFindu.net]] Web-based access to worldwide APRS real-time data.
*[[http://aprsearch.net/ APRS Search]] An APRS Search Engine.
*[[http://www.db0anf.de/hamweb/aprsdb/ DB0ANF]] APRS-IS Data Base Lookup Server shows individual stats on any given call sign.
*[[http://www.nashvilleaprs.net/apps/phgcalc.php PHG Calc]] Online PHG (Power Height Gain) Calculator.
*[[http://www.aprs2.net/ Tier 2 Network]] Tier 2 APRS-IS Servers Group
*[[http://www.aprs.com.ar APRS Argentina ]] Argentinian APRS Group (Spanish)
*[[http://ar.groups.yahoo.com/group/LU-APRS/ LU-APRS]] APRS Argentina Forum (Spanish)
*[[http://lu5agq.dyndns.org/buscat/ Busca-T]] Google Maps powered APRS stations search engine (Spanish)
*[[http://www.aprs.com.ar/mirate/intro.html Mira-T]] javAPRS powered APRS stations search engine (Spanish)
*[[http://www.aprs.net.au APRS Australia]] Australian APRS Web Site, References
*[[http://www.aprs.net.nz/index.htm NZ APRS]] New Zealand APRS website
*[[http://www.ohioaprs.net OhioAPRS]] Northeast Ohio APRS