You have two options to access to my APRS pages.
APRS Screen View: This takes you to a snapshot of my UI-View APRS map page directly from my APRS computer. This shows you the current stations in southern Maryland and the “tracks” of some of those mobile units I am actively tracking at the time. An icon will disappear after 90 minutes of inactivity. This page is set up to automatically refresh every two (2) minutes. If it doesn’t automatically refresh in your browser, just use your manual browser refresh button.
UI-View Web Page: This takes you to the web server add-in service for UI-View (the excellent Windows APRS program I utilize). This is a series of web pages that identify the various stations that my APRS station is hearing and considerable information that those stations are reporting.
APRS Introduction
The Automatic Packet Reporting System (APRS), developed by Bob Bruninga, WB4APR, allows packet radio to track real-time events. While the packet radio system did a great job with message and text transfer activity, its use has dropped off dramatically as a result of the Internet. While packet operations are currently a very useful resource during emergency operations, Bob saw the opportunity to further utilize the technology for the graphic display of station and object locations and movements. Bob developed the groundbreaking APRS DOS program to actively display APRS objects. Other authors have followed Bob’s lead and developed applications to operate on the Windows operating platform. The integration of Internet technology with Packet Radio technology has not only provided a new area of interest for Amateur Radio Operators, but has provided a very valuable tool for use during emergencies for tracking relief and recovery operations.
APRS has too many features for me to adequately address here. There are other sites that can provide these detailed descriptions and capabilities if you are interested. There are a couple of features that you will find of use as you view my APRS pages:
- Fixed stations: These can be identified by the house, antenna, or blue circle with “WX” in the center icons. The blue circle with the “WX” is an APRS weather (wx) station which provides real-time weather reporting for that location.
- Objects: These can be easily recognized by their blue colored label. They are locations that are important for others to know about but do not put out their own APRS position report. For example, you will see on my screen view “W3SMD” with the Red Cross icon. This is an object placed to identify the location of the Southern Maryland Chapter Headquarters of the American Red Cross.
- Mobile stations: These are identified by icons that indicate motion, like a car, van, truck, tractor trailer, boat, motorcycle, etc. If they are moving you will see their position change. The red line from the icon shows the general direction they are moving. If you see a mobile station with a red circle around it, that is a mobile station that has been identified to UI-View to “track”. You will see the map shift to follow any “tracked” mobile stations. For selected “tracked” mobile stations you will also see orange lines that show their route of travel along with small numbers indicating the order in which their position packets were received.
- Digipeaters: The yellow stars with a letter in the middle indicate the locations of a digipeater. A digipeater is a fixed location high power digital repeater that listens for beacons in their immediate area and rebroadcast those packets to a larger area using much higher power. These digipeaters provide the necessary retransmission of packets, particularly from mobile stations, into a larger regional area, often to other digipeaters that allows the packet to be heard much further than it would have just from the source transmitter.
- I-Gates: Some fixed stations have a blue box around them. This indicates that the station is operating an Internet Gateway (I-Gate). An I-gate takes position packets it hears over the air (RF) and retransmits them over the internet through one of the several major APRS servers. These reports can be monitored by any station connected to any of the servers since the packets heard are shared among them. This allows some stations to also operate as “reverse i-gates”, taking selected packets from the Internet and putting them back over the air. For example, my station takes weather bulletins put out over the Internet by the National Weather Service Sterling Virginia Office and retransmits them over RF to provide any local APRS station with the latest weather watches and warnings. These Internet servers are also source of position reports for the very powerful and useful Findu system which allows Internet query for specific stations.
These pages are experimental at this point and any comments you may have for improvement would be greatly appreciated.