ADS-B ground infrastructure

AOPA Finland • 17 November 2019
in community General Aviation

When do you think we could have the ground infrastructure of ADS-B covering Europe the way it does in USA today? This is relatively low cost investment and would decrease air space infringements, probably.

Basically, in which direction is Europe heading as far as ADS-B or any other form of Electronic Conspicuity is concerned?

Comments (11)

William Davies

How would ADS-B decrease airspace infringements? Aren't you mixing up with a GPS/moving map?

Emmanuel Davidson

ADS-B out provides ATC with enhanced functionalities. There is no more guessing about "what in the hell is he doing? where is he going?" in ATC's mind.
With 1090 ES, the data sent by the transponder is enhanced and allows for a prediction of the future trajectory. Having the call sign of the aircraft on screen, it is much easier to contact an aircraft.
Across Europe, we have many FIS areas. Most of the ATC guys manning FIS positions will go out of their way to warn an unsuspecting or distrécted VFR flight that he is about to enter restricted airspace. Since radar was allowed to FIS operators, in France, we have seen a significant reduction in airspace infringement. ADS-B out will help in this regard. Also keep in mind that there is some research being conducted to be able to send, within the ADS-B flux, a message sent to a specific aircraft (equivalent to PDLC)

Rudy Muller

uAvionix has executed a UAT weather trial with 7 UAT ground stations in the UK last couple of years.
Some more triels are about to start on the north sea at UK and Norway.
Everyone is enthusiastic and want to have full coverage of Weather services and traffic services over the country.
Also the project Operation Zenith at Manchester Airport was found to be very useful showing all traffic ADS-B + Mode C/S and Drones in an ADS-B rebroadcast visible on SkyDemon, EasyVFR, Foreflight, et cetera. Also during the Weather conference at EASA earlier this year it was general consensus that we need to do something with UAT in Europe. So, when you all ask your local authorities to start a UAT trial and find a way to finance this then the UAT roll-out over Europe could be reality. uAvionix is ready to facilitate the infrastructure.

Per Jensen

Here in Denmark we are in the full test phase for UAT out
Right now we are operating 2 UAT transmitters - One in Roskilde and on in Billund.
The plan is to make it a permanent solution, hopefully end 2020
have a look at for more details.

Emmanuel Davidson

AOPA France is in favor of the usage of ADS-B in Europe. Provided that we implement ADS-B through UAT (978 MHz). There are multiple reasons for this.
First of all, having all aircraft transmitting on 1090 MHz, is going to prove problematic in the future. The sheer amount of traffic causes frequency congestion in certain areas of Europe. Germany is well aware of this problem. If we were to be allowed to use UAT for General Aviation, the frequency congestion problem could go away pretty quickly. plus GA would benefit from traffic and weather services.
For the Traffic part, as ground stations would have to resend traffic information, nothing would prevent to create an aggregated uplink of that would include multiple sources. We could easily mix ADS-B, 1090 ES and Elementary 1090, Mode C and even raw radar data (usually sent by military stations. To this, we could add Flarm data.
There is little use to underline the benefits of receiving traffic and weather in the cockpit.
One of the reasons often cited to prevent the use of UAT is that it is a military frequency or that VORTACS are still using this band. To the best of our knowledge, both are incorrect.
So what prevents us from going to UAT? the cost of a ground station is ridiculous in regard to the maintenance cost of an ILS. ILS are removed every day in Europe. if we were to use part of the savings in one fiscal year, we could probably install three ground stations (one working two as automatic backup) for each location needed in a country. The state would still reap the benefits from the ILS removal on multiple years while the cost of UAT ground stations would be absorbed in the first year.
The cost of UAT transceivers is ridiculously low compared to a change of transponder. A while ago, we were forced to change our transponders to go to Mode S. We were told that Mode C did not offer enough codes to positively identify all the traffics flying in Europe. As aircraft owners, we had to make the investment with the money left in our wallets, after taxes. I installed my Mode S transponder in 2007. For four years, while flying in France or abroad, I always enquired if ATC could confirm that my Mode S signal was received properly. 90% of the time, I was told that this ATC facility could not receive Mode S but they could still see me. And, of course, I was given a 4 digit Xpdr code...
For four years I used a piece of equipment that I had paid for, but the party that forced me to spend the money could not use the best functionalities given by the hardware. I think it is fair to say that after paying for FM immunity, Mode S, and 8,33 radios, owners are not ready to pay more money while being forced to change equipment again, with no benefits to them.

The test, all across Europe, shows that a UAT ADS-B system, even with an integrated GPS that is not within the limits of the current certification needed for dashboard-mounted GPS offers a perfectly safe solution to ATC's problems. In return, the adoption of a proven and reliable standard, already adopted by the country where GA is the most prevalent only makes sense.

There is a fringe of techno enthusiasts that are contemplating the use of smartphone-based apps to bring the same benefits to GA that UAT would. I find it very difficult to believe for a second that us, pilots, would trust a system based on 4G, 3G, or lower technology, to provide us with a system as important as traffic avoidance, real-time aircraft positioning in 3D and weather transmission. Just think of the many occurrences where you need to reboot your favorite smartphone, find yourself in a blind spot for phone communications (not even talking about high-speed Internet!). Would you trust such a system for you and your passenger's safety? Not even going to mention that the companies providing the GSM and 4G infrastructure are making it very clear that their network is not happy with phones connecting simultaneously to cell towers from altitude. The system is not designed for this, and therefore they ban that form of usage in their contracts.

SO why not make it easy, simple, safe, and cost-efficient. We have all the technical answers today, but we are still debating what standard we should adopt, most of them being untested with a number of flights similar to reality. Only UAT (for the receiving part) has been tested in real conditions. Isn't that enough to make it the best contender?

Rudy Muller

I like to add to Emmanuel's post that study has proven that when using both 1090 and 978(UAT) with low power or very low power ADS-B there really is no congestion on the frequency. Also when unmanned is using very low power ADS-B and conditional transmitting. So, we can use 1090 and UAT for both General Aviation and Drones in order to safeguard the integration of manned and unmanned in the lower airspace...U-Space/UTM systems can use the UAT tower to manage and integrate traffic in an efficient and safe manner. We also started experiments with UDS-B, ADS-B for unmanned, on a third aviation frequency (available DME frequency).....we are on the edge on an exiting time where manned and unmanned traffic can fly safe in the lower part of the airspace.

AOPA Finland

We agree that ADS-B through UAT (978 MHz) is way to go forward because of known congestion problem of 1090 MHz. But how and when EASA will start process with stakeholders, especially with ANSPs?

Rudy Muller

Congestion of 1090 MHz is not an issue when you talk about See&Avoid/Electronic Conspicuity. This all has to do with (very) low power ADS-B and conditional transmission of ADS-B data for UAS. When we, like in USA, use UAT and 1090 and possible a third aviation frequency for Electronic ID for UAS & UDS-B (ADS-B for UAS) then there is no congestion in 1090 at all.....also when we all start using ADS-B we can shutdown interrogation by SSR and TCAS. Read the Mitre report on use of low power ADS-B and UAT/1090 (link below)......I think all associations need to request local CAA/ANSP to plan their business model for investment in UAT broadcasting...this can be of benefit for General Aviation and U-Space..........uAvionix Europe can help you with that.…

AOPA Finland

Hi Rudy,

Would you kindly shed some light regarding your business plan and product roadmap?

JP Kinos

As an addition to above I would like to notify that ADS-B IN to the airplanes only works via UAT frequency and the protocol supports more than just weather and traffic.
Most if not all modern navigator systems and tablet aviation software solutions today also read (in the air when connected to any ADS-B UAT receiver) trough ADS-B the notams and metars for example. They are therefore also capable to visually show to the pilot restricted airspace. Even danger area activations could be shown in real time. Just think about how much more flexibility and safety this type of real time information would give in our conquest air space here in Europe.
And, like many others already said, this technology is already there, it is proven and it is affordable. The only thing missing is the ADS-B ground infrastructure and service providers collecting and sharing the data.
The data already exists. Just take a look for example the which is actually already now collecting and showing all that information from Finland for free. Such information should just be translated to the existing ADS-B protocol and spread out trough the (non existing) ADS-B ground infrastructure.
Agree, it’s not exactly this simple but as you see all key elements exist, we must get this done. It’s not rocket science.

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