Install readsb and tar1090: your own local live map for your ADS-B receiver

Flightradar24, FlightAware and the like show you the sky as thousands of receivers see it together. Sometimes the more exciting question is what your own antenna is hearing right now – unfiltered, without delay, straight from your home network. That’s exactly what the combination of readsb and tar1090 is for: a powerful decoder and a map interface that many spotters consider the best local live map. This guide shows you how to install both on a Raspberry Pi, set them up sensibly and use them in everyday spotting.

readsb and tar1090: the short answer

You run the installation script from the adsb-scripts project on your Pi. It installs the readsb decoder and the tar1090 web interface in one pass. Afterward, you set your antenna’s location with readsb-set-location, let the gain regulate itself automatically and open your Pi’s address in the browser with /tar1090 appended. If you’re running PiAware and don’t want to change anything about it, you install only tar1090 – it also builds on dump1090-fa.

Building your own ADS-B receiver explains what hardware you need. How ADS-B works in general is covered in Flight tracking with ADS-B for spotters. This article is about the software.

What readsb and tar1090 actually are

readsb is an ADS-B decoder that its own developer describes as a “Swiss Army knife.” The version that almost all spotters use today is maintained by the developer wiedehopf. It is an independently developed fork of Mictronics’ readsb, which in turn emerged from dump1090-fa – at the beginning of this lineage stands the original dump1090. readsb controls the SDR stick, decodes Mode S, ADS-B and TIS-B messages and outputs the data in many formats: as a Beast and raw data stream, in SBS format for older programs and as JSON for web interfaces. What’s inside these messages is explained in Transponder modes A, C and S.

tar1090 is the interface that goes with it. It doesn’t replace a decoder but reads its data and builds a map from it with aircraft icons, a table, a detail column and tracks. tar1090 works with readsb and dump1090-fa; with dump1090-mutability it shows fewer details. You can tell the interface is good from its prominent users: the community trackers adsb.lol, adsb.fi, airplanes.live and also the ADS-B Exchange globe are based on tar1090. If you know these sites, you’ll find your way around your own map right away – more in Unfiltered community trackers compared and ADS-B Exchange explained.

Component	Job	Configuration
readsb	control the stick, decode signals, provide data	/etc/default/readsb
tar1090	live map, table, tracks and filters in the browser	/etc/default/tar1090 and config.js
lighttpd	web server that serves tar1090	set up by the installer

Clarify first: which route suits you?

An SDR stick can only be used by one decoder at a time. That’s why the readsb installer removes other decoders such as dump1090-fa and dump1090-mutability. This is the most important decision before you start.

For the third case, Feeding multiple networks at once with Ultrafeeder helps – tar1090 is already included in the container there – as do ADS-B reception without a Raspberry Pi and Flight tracking on your PC.

Step by step: installing readsb and tar1090

The prerequisite is a Debian-based system such as Raspberry Pi OS with internet access and command-line access, either directly on the Pi or via SSH. The stick and antenna are already connected to the Pi.

The instructions explicitly mention a few special cases: for the RTL-SDR Blog V4, the driver packages from Debian and Raspberry Pi OS aren’t enough, and it needs an additional driver installation. If you use an Airspy, you run the airspy-conf script after the installation; airspy_adsb then delivers the data to readsb. More in Airspy for maximum ADS-B reception. Which stick is worth it in general is compared in SDR sticks for ADS-B compared.

Updates are straightforward: you simply run the same installation script again. Your settings are kept in the process.

Only tar1090 on an existing system

If PiAware is running, you install only tar1090 using its own script from the GitHub project wiedehopf/tar1090. The map appears at /tar1090 here too. The readsb installer aborts by itself on a PiAware SD image anyway. How to set up PiAware itself is covered in Installing and setting up PiAware.

Setting gain and location correctly

The gain determines whether weak signals from distant aircraft arrive or whether nearby aircraft overload the stick. For RTL-SDR sticks, readsb comes with its own automatic gain control tuned for ADS-B. According to the developer, its basic values normally don’t need to be adjusted.

• Automatic: readsb-gain auto switches on the control.
• Fixed value: sudo readsb-gain 43.9 sets a fixed gain. That’s worthwhile if you want to compare deliberately over several days.
• Fine-tuning: All options are in /etc/default/readsb. After changes, you restart the service with sudo systemctl restart readsb; readsb --help lists all parameters.

Whether a change actually brings more range isn’t shown by the first five minutes but by statistics over days. That’s exactly what Measuring reception performance with graphs1090 from the same developer circle is for. Hardware levers such as preamplifiers and filters are described in Boosting ADS-B range, and the antenna itself remains the biggest factor – see Finding the best antenna location.

The location is more than cosmetics: without it, tar1090 can’t show distances or center the map on your station. Enter your antenna’s coordinates as precisely as possible. If you share data with networks that use MLAT, the exact position is mandatory anyway – why is explained in MLAT and multilateration explained.

tar1090 in everyday use: the most important features

At first glance, tar1090 looks like any flight radar map. Its strengths show in the details – especially for spotters who search specifically for types or registrations.

Filtering by type, altitude and callsign

In the sidebar, you filter by ICAO type designator, type description, callsign, altitude and data source. The filters understand regular expressions: B73. captures the entire 737 family, for example, and the description L2J all twin-jet landplanes. How the type designators are built is explained in IATA and ICAO codes explained. Additional info such as registration and type comes from a bundled database that tar1090 assigns by hex address – background in ICAO 24-bit address (hex code).

Keyboard shortcuts

Key	Function
Q / E	zoom out and in
W / A / S / D	move the map north, west, south, east
T	select all aircraft with tracks
M	multi-select on and off
C or Esc	clear selection
B	toggle map brightness

Tracks with pTracks: how far does your antenna hear?

If you append ?pTracks to the address, tar1090 shows all recorded tracks of the last eight hours. The result is the most honest picture of your station’s range: you immediately see in which direction buildings or hills cut off reception. With ?pTracks=2, you limit the display to two hours. In addition, you can use the getupintheair.sh script and a panorama dataset from heywhatsthat.com to overlay theoretical range rings for specific flight altitudes. However, these rings don’t take trees and obstacles in the immediate vicinity of the antenna into account.

Practical URL parameters

tar1090 can be controlled via additions to the address, which you can save as bookmarks:

• ?icao= plus hex address selects a specific aircraft; ?reg= works with the registration but loads more slowly – the project therefore recommends ?icao=.
• ?filterType=A388 shows only a specific type, ?filterAltMax= limits the altitude – handy for seeing only approaches.
• ?mil highlights military and other interesting aircraft.
• ?kiosk switches to a display mode without controls, for example for a screen on the wall.
• ?filterSources=mlat shows only aircraft whose position was calculated by multilateration.

You join multiple parameters with &. If you’re searching for individual aircraft, you’ll find more strategies in Tracking an aircraft by registration or hex code and Tracking military aircraft online.

Heatmap and replay

Some features require wiedehopf’s version of readsb: the heatmap, which shows where the most traffic ran over time, and a replay that plays back the history of all aircraft again. For this, you enable additional options in readsb such as --heatmap along with a directory for the history data. This is the real advantage over the combination of PiAware and tar1090.

Configuration: where things are

• /etc/default/readsb: Decoder options such as gain, network ports and additional features.
• /etc/default/tar1090: Interval and number of history snapshots; restart the service after changes.
• /usr/local/share/tar1090/html/config.js: Settings of the web interface. You enable a line by removing the two slashes at the beginning, then reload the browser. If you delete the file and run the installer again, the default values apply again.

Through its network ports, readsb makes its data available to other programs, for example as a Beast data stream on port 30005, to which the installer also connects fr24feed and rbfeeder, and, on request, in SBS format for older programs. This is how additional feeders or programs on your PC access it. How to connect more networks from here is shown in Setting up fr24feed, Feeding ADS-B Exchange and community networks and ADS-B feeder programs compared.

Typical problems and their solutions

• “Connection refused” in the browser: Usually the web server is missing. Install lighttpd with sudo apt install -y lighttpd and run the installer again.
• No aircraft on the map: Check the log with sudo journalctl --no-pager -u readsb. Is the stick seated firmly, and is the antenna cable screwed on?
• “Kernel driver is active” or “device is claimed”: A system driver is holding on to the stick. The instructions recommend blacklisting the affected DVB drivers and rebooting. If that doesn’t help, another program is accessing the stick.
• A feeder no longer delivers anything: The installer adjusts fr24feed and rbfeeder; you have to switch other programs to readsb as their data source yourself.
• Barely any range: It’s almost always down to the antenna and location, rarely the software. Build instructions are in Building a 1090 MHz antenna yourself.
• Back to PiAware: Turn off readsb with sudo systemctl disable --now readsb, remove tar1090 via its uninstall script and reinstall dump1090-fa.

What’s in it for you as a spotter

Your own map is the fastest tool before a spotting trip. A glance at tar1090 in the morning, and you see which direction the first approaches are coming from. At Munich Airport, for example, that decides whether you head to the visitors’ hill or to the other end; in Hamburg, whether the Affenfelsen works today. The logic behind it is explained in Understanding the runway direction in use at airports.

Then there’s the follow-up: with replay and pTracks, you match photos to registrations and flights after the fact. How to do that systematically is shown in Matching sightings with ADS-B logs. And before you pass on data or share screenshots, it’s worth a look at Receiving ADS-B data: the legal situation.

Conclusion

readsb and tar1090 turn your ADS-B receiver into a full-fledged local flight radar station. The installer does the main work, after which three steps remain: set the location, check the gain and verify that all feeders keep running. If you don’t want to touch PiAware, tar1090 alone already gets you the better map; if you want the heatmap and replay, you switch completely to readsb.