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- USING APRS IN THE SKYWARN SYSTEM
-
- The Automatic Packet Reporting System (APRS) is an ideal tool for
- reporting weather conditions via packet. The system is compatible with both
- human entry as well as automatic weather station entry of weather conditions.
- In the APRS system, current conditions at any station are broadcast to all
- stations on the net in a periodic fashion. Not only are these individual
- conditions available to all stations on the net, but also importantly, the
- location of these conditions are also displayed. There are several
- capabilities of APRS that are directly applicable to the SKYWARN system:
-
- MAP DISPLAY - Shows the location of all reporting stations, their wind
- speed and direction. Can also show the location of other objects, such
- as reports of TStorms, Hail, Tornados, etc
-
- REPORT BROADCASTS - The individual station weeather conditions can be
- placed in the Beacon Broadcast from each station
-
- OPERATOR MESSAGES - The Point-to-point message capability can be used
- for operator to operator messages and alerts.
-
- COMMENTS - Transmitted along with each position report, there is a
- short comment field which can be used to report station status,
- intentions or other broadcast type information
-
- VEHICLE TRACKING - APRS can track the movements of any mobile with a GPS or
- LORAN-C receiver properly interfaced to a packet TNC.
-
- SKYWARN APPLICATION: The map display has the capability of presenting both
- a station's position and his course and speed. APRS recognizes a special
- weather report indicator so that all weather reporting stations are highlighted
- in blue and the software recognizes that their course and speed indicators are
- for wind reporting and not for station course and speed. To indicate a weather
- report, the letters WX: must be inserted as the first characters in the comment
- field. The rest of the comment field is free-format so that weather reports
- can be tailored to the conditions at any time. In addition to the brief
- weather report, the station's Beacon Text is also available for broadcasting
- additional amplifying information. Any station running APRS simply calls up
- the LATEST display and sees the current conditions from all stations on one
- screen. Similarly, he calls up the map display and sees the location of all
- stations and all specially reported conditions. Any authorized station can
- insert the location of any special object on the map. The location of that
- reported object or condition is displayed on all screens in the network. We
- use APRS every weekend for reporting the Chesepeake Weather and Traffic net.
- Load the SKYWARN.BK file to see the APRS network during one of these nets.
-
- REMOTE SENSORS: Another advantage of the APRS system is the ability to
- display information from remote environmental sensors. We are currently
- working on simple weather sensors to be interfaced to a TNC which will
- automatically report their position and weather conditions once every 10
- minutes. These stations will appear on the map and their reports be visible
- using the LATEST display just like the home stations. It is planned to place
- a weather node at the location of every wide area digipeater used in the APRS
- system. Currently weather nodes are under construction in Maryland at Point
- Lookout in the south, Patuxent Naval Air Station, Chesapeake Beach division
- of NRL, Annapolis, Baltimore, and NorthEast. These sites will not only
- provide automatic weather reporting capabilities all along the Chesapeake Bay
- area, but will also form the backbone network for reporting the movement of
- radio amateur's boats with GPS and LORAN-C. Load the WXSTNS.BK file.