Aprs.fi user guide

This is the official manual for the aprs.fi web service.


The aprs.fi web service collects information from the Automatic Packet (or Position) Reporting System Internet System (APRS-IS). APRS is used by amateur (ham) radio operators to transmit real-time position information, weather data, telemetry and messages over the radio. A vehicle equipped with a GPS receiver, a VHF transmitter or HF transceiver and a small computer device called a tracker transmits its location, speed and course in a small data packet, which is then received by a nearby iGate receiving site which forwards the packet on the Internet. Packets are also retransmitted on the radio channel by digipeaters to enhance the coverage of the system. Systems connected to the Internet can send information on the APRS-IS without a radio transmitter, or collect and display information transmitted anywhere in the world.

In addition to that, aprs.fi also displays AIS data transmitted by most large ships. AIS transmissions are received by volunteers at numerous sites, but most areas are largely uncovered.

This guide aims to become a comprehensive manual for the aprs.fi web site, and as such does not attempt to describe the APRS or AIS systems in detail. To get started with APRS, please consult the following pages:

AIS is described well on the Wikipedia page for Automatic Identification System.

Languages and localisation

The aprs.fi service has been translated by volunteer users to numerous different languages. The language shown to you will be selected based on your browser's language preference settings. If you wish to preview the site in different languages, please prepend the two-letter language code to the site URL, for example:

The site also supports different measurement units (metric, imperial and nautical), which can be selected in the preferences.

Site navigation links

Image of site navigation links

Each page has a set of navigation links at the top of the page, and another at the bottom. On the real-time map, the links are provided in the navigation bar at the right side of the map, which can be hidden by clicking the button in the top right corner of the page.

The general idea is that the links on the top provide links to different data views. If you have already looked up a specific station, the links will contain that callsign, and clicking on the weather link when viewing the info page of a weather station will give you that station's weather history graphs.

The links at the bottom page provide links to static content pages such as the FAQ and this user guide, which give general information about the whole site.

There are a few exceptions to these rules, of course – the My account and Moving stations links, for example.


To ease up browsing and editing the guide has been split into separate pages for each section.

Common features : Describes features which are common to many or all of the different views of the site, such as searching using wildcards and table sorting.

Real-time map : Describes the main feature of the site, the real-time map.

User account : aprs.fi account: Signing up, deleting account, forgotten password procedure, changing callsign.

Preferences : Goes through the Preferences dialog, which allows you to customize aprs.fi to your liking.

Info pages : Describes the station info and station graph views.

Static maps : Introduces the static maps feature.

KML and Google Earth : Describes how to view aprs.fi in 3D using Google Earth.

Web stations : Updating your position on aprs.fi using a web browser, a mobile phone, or Google Latitude.

Messages, status messages and the Bulletin Board : Describes the messages, status messages and bulletin board views.

Weather : Describes the weather data visualization features of aprs.fi.

Telemetry : Describes telemetry collection and viewing.

Raw packets and Beacons : Raw APRS and beacon packet listings.

Prefix browsing

Network tools : Tools for people who run the digipeaters and igates of the APRS network.

Exporting data : How to download APRS position data from aprs.fi to your computer.

Troubleshooting : If you're having problems using aprs.fi, or if you think you've found a bug, please start reading here.

Discussion group, blog and other points of communication

If you have any questions, answers, ideas, tips or tricks, please share them on the official aprs.fi Google Group. It's available as a web-based forum and as a regular mailing list. Before posting, please read the instructions on the forum's front page, especially the requirement for as many relevant details as possible (including exact callsigns and page links in question). The forum exists strictly for discussing the aprs.fi web service – please use the other relevant forums for discussion about generic APRS issues or tracker configuration problems.

Please read through the Troubleshooting section before posting to the discussion group about any problems. Thank you!

News about the aprs.fi service are posted on the aprs.fi blog, which can also be subscribed over email, or using an RSS reader. Headlines from the blog are shown regularly in the lower right corner of the real-time map.

News items, even the smaller ones, get posted on the aprs.fi Twitter account.

aprs.fi user guide