Receiving and sharing ADS-B data: what is allowed in Germany, Austria and Switzerland?

Your own ADS-B station on the roof is the next logical step for many spotters: You see live what is flying over your house, and you supply data to Flightradar24, FlightAware or ADS-B Exchange on the side. Sooner or later the question comes up: Am I even allowed to receive these signals – and may I pass them on? Germany, Austria and Switzerland have different laws on this, and the situation is not quite as clear-cut as with airband radio. This article classifies the relevant rules, shows the gray areas and gives you practical rules for everyday feeding.

The short answer

Owning and operating an ADS-B receiver is unproblematic in all three countries – it doesn’t transmit anything and needs no frequency assignment. The real question is whether the signals you receive count as messages “not intended for you.” In Germany, § 5 TDDDG (the Telecommunications Digital Services Data Protection Act) decides that. ADS-B is sent unencrypted to all receivers in range, that is, to an indefinite group of people – which suggests that reception and passing on are permitted. However, we don’t know of any explicit confirmation by courts or authorities. What is, in the widely held view, not covered is listening to and spreading voice radio, more on that in Listening to airband radio: the legal situation.

What ADS-B is technically – and why that matters legally

ADS-B stands for Automatic Dependent Surveillance–Broadcast. The aircraft determines its position by satellite navigation and broadcasts it at short intervals together with altitude, speed, callsign and its 24-bit address. In Europe, this runs over the Mode S transponder on 1090 MHz – the basics are covered in Transponder modes A, C and S explained and ICAO 24-bit address (hex code).

Two properties are decisive for the legal assessment:

• Broadcast instead of conversation: The “B” in ADS-B stands for broadcast. The signal is not aimed at a particular counterpart but at everyone who can pick it up – air traffic control ground stations as well as other aircraft with the right equipment.
• No encryption: The messages are openly readable. Any off-the-shelf SDR stick with free software such as readsb or dump1090 can decode them.

ADS-B Out is mandatory in Europe under EU Implementing Regulation (EU) No 1207/2011 for fixed-wing aircraft with a maximum takeoff mass of more than 5.7 tonnes or a maximum cruising speed (true airspeed) above 250 knots. The requirement does not apply to most light general aviation aircraft; many transmit voluntarily anyway.

The case is different for aircraft that have a Mode S transponder but don’t transmit a position. The networks calculate their location by comparing arrival times at several receivers – this is explained in MLAT and multilateration. Here, too, you are only evaluating what the transponder radiates openly anyway.

Germany: § 5 TDDDG and the eavesdropping ban

The German eavesdropping ban used to be in the Telecommunications Act and is now found in the Telekommunikation-Digitale-Dienste-Datenschutz-Gesetz (TDDDG). § 5 has three paragraphs that you should know as a feeder.

Paragraph 1: what you may listen to

With a radio device – which includes your SDR stick – you may only listen to, or take note of in a comparable way, messages that are intended

• for you as the operator of the radio device,
• for radio amateurs,
• for the general public or
• for an indefinite group of people.

The last point is decisive for ADS-B. A signal that goes to every receiver in range without an addressee and without encryption can reasonably be understood as a transmission to an indefinite group of people. That is exactly what the spotter scene has argued for years.

Paragraph 2: what you may pass on

For all other messages, a strict disclosure ban applies: Neither their content nor the mere fact that you received them may go to others – even if the reception was unintentional. For feeders, this is the core of the question. Anyone who supplies data to a network shares it with a service that in turn publishes it worldwide. If ADS-B falls under paragraph 1, that is uncritical. If it did not, sharing in particular would be problematic.

Paragraph 3 and the penal provision

Paragraph 3 makes clear that special statutory authorizations remain unaffected – for authorities, for example. § 27 TDDDG makes prohibited eavesdropping and prohibited disclosure a criminal offense: for intentional violations, up to two years in prison or a fine.

So how should ADS-B be classified?

Quite a lot speaks for classifying it as a permitted transmission:

• ADS-B is technically designed as a broadcast and does not address a particular counterpart.
• The signals are unencrypted and readable with standard hardware.
• Large flight tracking services have published the data openly worldwide for many years, backed by thousands of private receivers, including in Germany.
• We are not aware of any proceedings against a private ADS-B feeder in Germany.

To be honest, though, this also belongs here: We have not found a court decision or an official statement from the Bundesnetzagentur (Germany’s Federal Network Agency) specifically on ADS-B. The classification rests on an interpretation of the law and on years of established practice – not on a binding clarification.

The crucial difference from airband radio

Many spotters lump ADS-B and airband radio together. Legally, that is wrong. Voice radio between cockpit and air traffic control is aimed at the specific participants in air traffic, not the general public. In Germany, in the widely held view, it is subject to the secrecy of telecommunications – listening in without authorization is then not covered, and the disclosure ban from § 5 para. 2 TDDDG applies to spreading it. That is why radio audio tracks don’t belong in YouTube videos or livestreams; details are in Publishing airband radio in videos.

The rule of thumb for your everyday spotting is therefore: ADS-B station on the roof – fine under prevailing practice. Scanner on the tower frequency at the fence – not in Germany. If you want to get more deeply into radio, the legal route is a radiotelephone certificate.

Austria: TKG 2021

In Austria, the topic is regulated in the Telecommunications Act 2021 (TKG 2021). The relevant provision is § 161 para. 4 TKG 2021: If a radio device or another technical device unintentionally receives messages that are not intended for that device or its user, neither the content nor the fact of reception may be recorded, disclosed to unauthorized persons or used for any purpose. Messages already recorded must be deleted or destroyed.

For ADS-B, the same basic question therefore arises in Austria as in Germany: Are the position reports “not intended for you”? Anyone who shares the broadcast argument concludes that the provision doesn’t apply. We have not found an official clarification on this. In addition, the Austrian constitution protects the secrecy of telecommunications, and the Criminal Code has an offense in § 119 StGB against gaining knowledge of messages not intended for the offender by means of a device attached to a telecommunications system or made ready to receive. In Austria, too, spotters run receivers and supply the well-known networks. If you want to play it safe, ask the responsible telecommunications authority.

Switzerland: little that is concrete

In Switzerland, the Federal Constitution guarantees the protection of telecommunications in Art. 13, and the Telecommunications Act (FMG) contains further rules on the secrecy of telecommunications. We did not find a public, clear statement specifically on private reception and sharing of ADS-B data in our research. Practice is similar to that in Germany and Austria: In Switzerland, too, private stations run that supply data to international networks. Binding information is available from the Federal Office of Communications (BAKOM), which is responsible for radio and frequencies. If you are out and about in Switzerland, you will also find rules of their own on drones there – see Flying a drone in Switzerland.

Overview: three countries compared

Criterion	Germany	Austria	Switzerland
Key provision	§ 5 TDDDG	§ 161 para. 4 TKG 2021	Secrecy of telecommunications (Constitution, FMG)
Owning and operating a receiver	allowed	allowed	allowed
Receiving ADS-B	permissible in the widely held view, not explicitly settled	not explicitly settled	not explicitly settled
Passing on to networks	common practice, legal question open	common practice, legal question open	common practice, legal question open
Listening to and sharing airband radio	not covered, passing on prohibited	check local rules	check local rules
Point of contact	Bundesnetzagentur	telecommunications authority	BAKOM

Beyond radio law: data protection and responsibility

Even if reception is fine under radio law, your responsibility doesn’t end with the signal. There are three points to keep in mind.

1. Personal data: A Lufthansa scheduled flight says little about individuals. A private jet or a small sport aircraft, on the other hand, can clearly be traced to one person. Anyone who permanently documents and publishes the movements of a specific owner touches personal rights and data protection – and, in extreme cases, criminal law as well if it amounts to stalking. How data protection applies to photography is explained in People in spotter photos.

2. Respect blocking programs: Commercial services hide certain aircraft, for instance at the owners’ request or through the US LADD program. Community networks such as ADS-B Exchange say they don’t apply such filters. What that means, you can read in ADS-B Exchange explained and in the comparison Unfiltered community trackers. Just because you can see something doesn’t mean you have to spread it.

3. Military and authorities: Military and state flights often transmit a position only in a limited way or not at all. Anyone tracking them via MLAT should not share live data in a way that could endanger operations or people. Background is in Tracking military aircraft online and Spotting government aircraft.

Practical rules for feeders

From the law and established practice, you can derive a few simple rules that keep you on the safe side.

You will find the technology behind it in the practical articles: Building an ADS-B receiver yourself, Setting up fr24feed, Setting up PiAware and Feeding multiple networks at once. What you get in return is shown in the comparison Free subscriptions for feeders. The difference from UAT on 978 MHz, which is used mainly in the US, is explained in UAT on 978 MHz.

And at the spot?

On the go, too, many spotters use ADS-B: via an app on the phone or with a mobile receiver on a power bank. Under radio law, the same applies as at home. How to put together a small setup for the fence is covered in Mobile ADS-B reception at the spot. And if you want to match your sightings against log data afterward, Matching sightings with ADS-B logs helps. Anyone spotting abroad should know the local rules beforehand – a starting point is Spotting abroad.

Conclusion

Running an ADS-B receiver is not a problem in Germany, Austria or Switzerland – it doesn’t transmit anything. Whether reception and passing on of the signals are covered under radio law depends in all three countries on the question of whether ADS-B counts as a message to the general public. For Germany, a lot speaks in favor: open broadcast, no encryption, years of practice by thousands of feeders. But the question is not conclusively settled. The situation is much clearer with airband radio: Listening in and spreading it are considered not allowed in Germany in the widely held view. And regardless of any statute: You handle data that leads back to people with care.