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.
All APRS-data published on this website is received from the APRS-IS network. The data published on this website is not owned by us, it is publicly available information that has been sent to the APRS-IS network by users all over the world. Data sent to the APRS-IS network is in the public domain, as all ham radio transmissions (by FCC rules in the US, and according to similar laws in other countries).
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.
Warning! It is not allowed to use the APRS Direct Websocket API without using the APRS Direct js file. Improper use is likely to be blocked (all requests to our Websocket API from unknown origin are logged).
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)...
If you do not want your APRS data to be publiched on APRS-websites like APRS Direct you can append NOGATE to the end of your path (or use RFONLY). If your digipeater path is WIDE1-1,WIDE2-1, you just change it to WIDE1-1,WIDE2-1,NOGATE.
Using NOGATE (or RFONLY) is much better than APRS Direct having its own solution to control which packages may be displayed, since NOGATE (and RFONLY) will affect all APRS websites.
If you use NOGATE (or RFONLY) your data will not be published on APRS Direct (we will delete it if we receive it by mistake), but we can not guarantee that all other APRS websites and IGATES is obeying NOGATE (and RFONLY). The information sent on ham radio frequencies is in the public domain (by FCC rules in the US, and according to similar laws in other countries). Which means that we can not force other APRS websites to not publish your APRS data. If you want to be absolutely sure that nobody sees the data you are sending, do not send at all.
Okay, let me tell you more about our brilliant marker logic :-)
To save performance we have decided to only enable the longer time options when we are filtering.
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In the search box, you can enter different prefixes that allow you to search for other parameters than name.
CMT: Search for stations with a specified comment.
MSG: Search for stations with a specified beacon.
STAT: Search for stations with a specified status.
WXCMT: Search for stations with a specified comment in latest weather packet.
Note that we will only search in the latest comment, beacon or status from the station.
You may use * as a wildcard. To search for stations that has a comment that contains the word "aprs" use the search "CMT:*aprs*"
The coverage map consists of two parts:
The max range plot is created by:
The max range plot method to create a coverage map is not perfect, but in a situation where you have very few measurement, it is difficult to create a better coverage map. Together with the heatmap, our interploated max range plot polygon is a good tool for determining how large area that is covered.
Note that we only include coordinates from moving stations, otherwise the covered area would be to large, and the result would not be as interesting.
You may use my symbols freely as long as you include an attribution. It's enough if you mention on your website that the symbols are provided by APRS Direct (www.aprsdirect.com).
Download the symbols here.
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