Got Questions? We've Got Answers!
APRS (Automatic Packet Reporting System) is a digital communications system that uses packet radio to send real time tactical information (on amateur radio frequencies). The APRS network is used by ham radio operators all over the world. Information shared over the APRS network is for example coordinates, altitude, speed, heading, text messages, alerts, announcements, bulletins and weather data. APRS has been developed by Bob Bruninga, callsign WB4APR. More information about APRS can be found at www.aprs.org or at wikipedia.
APRS Direct is a website that brings you global real-time APRS tracking and weather data. Our goal is to bring you a fast and easy-to-use map with the latest APRS activity.
Our goal is that APRS Direct should work on all broswers that supports websockets (an HTML5 feature). The following browser version (and newer) supports the websocket-protocol. We havn't tested all the following browsers, if you find a problem please mail me.
Sure! Follow the following instructions...
Yes, that is possible. Look at this jsfiddle-example.
The websites you compare are not collecting packets from the same APRS-IS servers. Each APRS-IS server performes duplicate filtering, and which packet that is considered to be a duplicate may differ depending on which APRS-IS server you ask. The APRS Direct website collects it's packets from our own APRS-IS server, which is connected to a APRS-IS core server.
When we receive a new packet from APRS-IS (we receive about 50-100/second) we need to decide if this packet belongs to a moving station and if the new position is likly. If a position is very far away from the latest position it's more likly that the new position is faulty (probably a bad gps signal). The distance that is likly may differ depending on how fast a station is moving.
If we decide that a new position is unlikly we will consider it to be a ghost-marker. A ghost marker is a marker that is not shown on the map by default, but they can be shown by clicking "Show ghosts markers" in the menu. When a ghost marker is visible it will be a bit transparent, that is how you distinguish a ghost marker from a regular marker.
If we later receive another packet that indicates that the station actually was moving in the same direction as the ghost marker we will convert the ghost marker to a real marker, and include the position in the tail. By doing this we avoid filtering out packets that actually is correct.
Yes we can, but there is a catch (or actually two)...
Select date and time to show map data for (enter time for your locale time zone). The regular time length select box can still be used to select how old data that should be shown (relative to selected date and time).
*Note that the heatmap will still based on data from the latest hour (not the selected date and time).
Date and time:reset