ADS-B network and data extraction - Julian Sube - Skysquitter

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Posted by Vincent Lambercy
You don't have to be a large company to be successful in ATM. That's something I've always be believing in. I mean at Fox ATM, we are seven of us and I always had a sweet spot for smaller companies that offer different alternatives to what the bigger one have. And today, this is something we will address. My name is Vincent Lambercy. This is an episode of the Radar Contact Podcast, and today my guest is Julian Sube, who is one of the co-founder of a company called Skysquitter, which operates an ADS-B network across Europe. But we'll come that in a second. Julian, welcome. Thank you for being our guest . Can you please start by introducing yourself, your career, and tell us what brought you so far?

Yes, thank you. Thank you Vincent Thank you for the invitation and I'm happy to be here. Thanks for the intro. Yeah. My name is Julian Sube, originally from the Frankfurt area in Germany, and I'm one of the three co-founders of the company Skysquitter. Just a few facts to my background. Originally I'm an electronic engineer with some additional qualification in business administration. I also fly myself, so I hold a private pilot license. I have been passionate about aviation actually since being a kid. To my career... I started off my career as a young project engineer in airfield systems. I did planning of electrical systems like airfield, lighting, navigation aids, aircraft docking systems and so on. And I actually still work in this field as a freelancing engineer and consultant when I have the time. But actually I don't have that much time because in 2017 I had the privilege to found an own company named Skysquitter with two friends of mine, which also are actually experienced professionals from the ATC and ATM industry.
The idea was actually to bring together the individual know-how of everyone involved. Yeah, let's be honest here. Also to do some fun stuff with focus on air traffic surveillance. I have to add, we are also a licensed amateur radio operators, so it's even more linked to our personal interest. Since then, we worked in several projects related to this field. For example, we did develop software for encoding and decoding several radar data streams and data formats. We supported the certification of commercial ADS-B receivers. We were also part of several research projects dealing with radar data analysis and let's say the innovative use of mode-s data. On top of that we do consulting and we provide live data streams for several kinds of applications. And yeah, as you already mentioned in the intro, we are also operating in our own ADS-B mode-s receiving network. Maybe just to add some examples for our customers, they're ranging from big academic institutions and universities to ANSPs and also smaller companies within the aviation industry, all with a focus on surveillance.

Okay, thank you for the intro. You covered a lot of things already that we need to dig into one by one. Let us start with the core of the company. So basically you do something which is operating that's network of ADS-B receivers across Europe basically. Same thing as FlightRadar, FlightAware and OpenSky to just name a few. But there are few core differences and your approach is slightly different. How do you go with operating your network? What makes you different from others?

Yeah, there are lots of great networks out there. Of course, we don't want to be the 20th version of the ADS-B crowdsourced network. I think I have to go a little bit back in time to explain the idea of this network. Actually we came up with this idea during a time when we were part of a research project dealing with the innovative use of raw mode-S, raw mode-S data where we developed algorithms for turbulence estimation and also for calculation of other meteorological parameters out of transponder data. We were in need of high quality and precise timestamped raw mode-S data since this was what, this is a real-time application. And yeah, we worked with several data sets from other networks and then we decided let's just put up an own receiver we can control which is completely in our hands. And that was just the beginning of this network.
Over a time period of let's say two, three years, this idea evolved and nowadays we are operating more than 50 receivers throughout Europe. Initially just to give us a good European picture of high altitude winds. That was just the beginning of this idea. And speaking of differences, the main difference is that we are not crowdsourced like the other bigger great networks. So we own all the hardware, we know all the antenna sites, we did the planning of the antenna sites by ourselves and the data is streamed via a secure VPN to our backend. So it's a complete closed system just in our hands. Yeah, we have full control over. Another thing is we have precise GNSS time synchronization of course throughout the whole network and we have monitoring system for all the receivers. There's no crowdsourcing involved at all. And this is the main difference because while crowdsourced networks, they have big advantages of course over our idea when it comes to coverage. We don't want to beat the coverage of any of those networks.
Of course this is not our goal, but there are also some disadvantages, some differences because we've been working with the data from different big networks and we know that there's problems every now and then with data quality like precise timestamps, which are really crucial if you're not only looking at the map or doing historical data analysis but really running a realtime or near realtime application using the raw surveillance data. So we are not dealing with let's say, faulty receivers, lagging networks, faulty timestamps, jamming attacks for example. Jamming attacks are a big issue in every crowdsourced application of course. And for us in our application, this really made a difference. And yeah, we also have some customers obviously thinking the same. And since the network is completely in our hands, we provide coverage and even complete close systems on customer requirements like providing data of specific, let's say airfield, airspaces or just different parts of the world where additional and reliable coverage is needed and is crucial for a project and we can adjust and integrate into existing systems. So I'd say we're really just aiming towards the B2B and more professional applications here where there's some kind of custom solution and deeper knowledge is needed. And well, we are completely independent of any strict business model or fixed contracts. And I think that sets us apart from the other networks.

The technical person in me wants to dig a bit deeper because I know these timestamping issues can be a massive problem in timestamping regarding crowdsourced networks. But I think another issue can be the type of hardware they use because if you look at some of those other networks, some are fed by, to put it a bit aggressively, $30 or 30 euros receivers, and this can also lead to some kind of issues. So I imagine you having complete hands over the network, the antennas, the receivers and everything is probably helping you basically not having some problems that the other networks have. Right?

Yeah, that is true obviously. And during our time experimenting with different receivers and also antenna systems, which is actually something we did before starting the company. So as I mentioned, it's it's all linked, closely linked to our personal interests and we really were able to choose the best hardware for this purpose and we're not using consumer hardware, which is actually not really suitable for a 24/7 operation. So our receivers, they're certified for 24/7, yeah, 24/7 operation and we have years of experience dealing with those receivers. We tried different GPS antennas, we tried several different receiving setups and now we ended up with a good overview what actually works and whatnot. And yeah, now we're pretty confident that we can ensure best data quality possible.

I also imagine you pick up the sites where you put your antennas because you don't have so many antennas compared to maybe larger networks. And I mean I know that firsthand because FoxATM provides Skysquitter with a site in Vilnius, so I know the process a bit. Can you tell us a bit more about what kind of sites you're after? How do you pick up the places where you put your antennas? Because I assume it's just not on everybody's balcony, right?

Yeah, that's true. And it's also a matter of the costs because we own the hardware and when we deploy a new antenna site, of course we like it to be with a great view to all directions with a clear view to the horizon with a stable internet connection. Sometimes we use UPS for power supply. So this is something we consider with every antenna site and those are our requirements. So we are not putting up antennas on balcony just because we don't have thousands of receivers. So we go more after quality than quantity. And since we were looking mainly at the upper airspace at first, we liked our receivers to cover, yeah, a huge orb, let's say the best possible amount of the airspace. And this is also a challenge if you have very good antenna sites, the mode-s message rate is really, really high.
So for example, some of our sites, they do have a message rate of more than three and a half thousand mode-S messages decoded every second. I think most of your listeners who dealt with ADS-B in general, they tried to receive signals with a ADS-B dongle with those little SDR dongles for example. And the best we ever best result we ever achieved with those little dongles is around 1000, maybe 1300 messages a second, and then they're on the limit. So this is also something to consider if you're operating good antenna sites, that your hardware has to be capable of providing this high message rates and decoding properly.

So you mentioned you cover mostly upper airspace. I mean the limited number of receivers means you won't the aircraft on the ground at every airport on airfield like some other networks can offer. What is your coverage for now? Because we say Europe, but Europe tends to be a fuzzy thing, depending which kind of Europe you are talking about. So what is your coverage from now on, and are there holes where you'd like to have new receivers put in operation?

Speaking of upper airspace, our coverage is almost complete in Europe. I think we have some gaps in Norway, Northern Norway areas where there's not that much traffic to be honest. Also the direction of Turkey, there's some holes, but looking at the upper airspace we're pretty well covered there. The reason, maybe I'd like to add that the reason why we were looking at the upper airspace was to get this picture of the wind situation over Europe and with the wind situation we are looking at the cruise altitudes basically. And of course it it's way easier to establish coverage in high altitudes than it is to establish ground coverage everywhere. It's obviously easier. With the deployment of the receivers, we already see that we cover the main airports because if there's a chance to be near to an airport in a good high quality antenna side, you have both, you have the high altitudes and you also have the lower altitudes, maybe also ground traffic. So we try to address that. But of course there also has to be a use case. So we are not just putting up receivers for simply no specific reason, we try to expand wisely where there's actually use case.

Okay. So if some listeners in Turkey have professional sites with nice availability and nice view of the horizon, are you open to requests?

Of course. Of course. We're not open, not only open to requests, we're also open to connect to anyone who's interested. Of course,

Who knows, maybe some of our listeners in the area can join and help you. Obviously you are operating the network, you can provide the live positions, the data and everything. But I guess with your expertise you can do much more than that. So what extra can you offer?

Yeah, speaking of live positions, maybe it's interesting to know that live positions are really just a small part of mode-S in general, it's only ADS-B, which is providing any kind of 3D or 4D position information. And most people don't know that ADS-B, which is obviously just a part of mode-s to be specific, it is downlink fromat 17 of mode-s. It only makes up around, let's say it depends on where you are of course, but let's say not more than 20% of all mode-s messages. So there's much more information in the air that can be decoded and is interesting. For example, TCAS, the whole TCAS system avionics information, deep insights into the technical parameters of a flight that is important to know. So there's so many information you can get out of mode-s and we can provide all of them.
We can also do precise mulitlalteration system to provide position of targets which are actually not ADS-B equipped and actually we're deploying complete MLAT installations on customer requirements for that. So we just recently had a new installation in southwest Germany for this reason. And well, as I already mentioned, we also do data processing and calculate metadata out of it. So we provide life weather information like the wind speed and direction, barometric pressure, turbulence information and also temperature. We backtested all those algorithms with real aircraft, with weather models and also with research aircraft, developed several algorithms for let's say bias correction and quality control in general. So from our perspective and from the feedback we get, this data can be actually very useful for ATC and ATM applications and for further research. So this is something we can provide. There's AMDAR right now, maybe some of your listeners heard of AMDAR, which is also providing weather information, but it's a completely cooperational system.
So aircraft have to be equipped with AMDAR equipment. Of course they have to be part of the game and in our case, there's no need of any additional onboard equipment because we are just listening to mode-s data. So we basically use aircraft as sensors without them knowing it. This makes it from our perspective and very interesting, a new data source and we can provide this data from the existing network. We can also provide custom coverage or completely closed systems, for that case. I would have to check for data quality, but in general we could also apply those algorithms to existing data streams of other sources. So it has not to be from our network, but it has to be high quality raw data to get good results.

You participate in some research projects in the past and I think you are still active in that field. Is that pure ATM research or is it more general? Can you tell us a bit more about that?

Most of our research projects were just ATM in general dealing with surveillance data. But we also had one little bit different projects where we put up radio sondes to monitor the frequency spectrum from the stratosphere, which was very interesting, A little bit different project because we like to do some hardware development as well. I wouldn't say was a project by accident, but it was a great opportunity for us to do something special. But most of the other projects where ATM related, yeah,

I like "project by accident", that's something we know pretty well. And to be honest, and I don't know if you agree on that, but quite often the project by accident as you call them, are the best one and the funnier one, right?

That's true, that's true.

So you have a lot of experience and expertise within Skyquitter. So you provide data, you take part in research projects, but you also have a consulting part of the company. Can you tell us a bit of what you have been doing in that area and how you can help other companies achieve their goals?

Yeah, that's true. Actually. One of the reasons why we started the company was providing consulting services because we think that we offer a quite unique combination of knowhow. We have the part of an active air traffic controller and software developer in the founding team. We got a data scientist working in the ATM industry for over 15 years. So that's the founding team and of course myself and I think it makes up an interesting team. We know what can be done with surveillance data and what cannot be done and we confidently call ourselves the mode-s experts. So of course we like to support with that know-how in all kind of project where this might be valuable as consultants and developers. So we did software development related to mode-s. As I mentioned in the beginning, we help with certification processes and we open to many, many more. So that's always interesting for us also to learn more about the needs of the industry and to see if we can add some value.

What kind of customers or project are you looking just after what you've said? Because with that kind of skills, you can go directly to an ANSP, you can go to research institutions, but sometimes it's not easy to work with the big guys. So are you more looking for smaller projects and smaller teams or are you open for everything?

Of course we are open to any customer and projects where our know-how and services are valuable. We'd also like to be involved in another research project because we think that with our industry knowhow and from our other professional careers, we can always bring some good input. But we know that the research projects are sometimes a bit difficult. Yeah, it's a high administrative effort to be honest, for small company. We always enjoy to hop in for some kind of subcontracting doing our work and doing what we can do best. We would also like to expand our activities abroad. So aviation is a very international industry and to focus just on the German speaking areas can be, I wouldn't say boring, but maybe it's time for also something new in other countries. And of course other than that, our focus is to find customers or partners to continue our work with our live meteorological data.
Since we finished the research project recently, we are now looking to bring this idea into some kind of operational application or have a cooperation to find out how it can work in an operational application. And therefore we are targeting at ANSP, of course airlines, airline suppliers, and also meteorological institutions, basically everywhere where life weather information from the airspace is interesting because I think we all know that weather is one of the most important factors in aviation, reducing capacity, causing delays and more emissions. So we are confident that this new data source can be a great addition to existing systems. That's why we like to find new partners and projects regarding that or just have a good discussion, of course.

I'd like to take a step back here and come back to what I said in the introduction, that there is no need to be a large company to be successful or do interesting things In ATM, what is your own experience being a small company active in the domain?

I think you could fill the whole podcast with this question to be honest.

I know it's not easy and I mean I'm in the same position running FoxATM for five and a half years now. I struggle with that every day, but it's always nice to have the opinion of others.

Yeah, I mean I can only speak for ourselves, they're not for any other small company, but I guess some basic things are the same for most of the active companies. I think first of all there's a big difference between the small company in that case Skysquitter and most of the customers because we are small, we are flexible, fast. Most of the time. We don't have any kind of compliance board or we don't deal with internal politics. So I pretty much like that as a co-founder of course, especially working for bigger companies in the past. So that's a good thing being a small company. But for the most of the potential customers or the existing customers, it's more like the opposite, especially in the research setting if you're working with universities and so on. And I think it can be a bit frustrating at times when you see that good ideas and projects are not realized because of some internal restrictions or politics sometimes just because of very long internal processes where actually might be difficult to keep up the motivation for everyone involved. So I think most of the small companies know that people have apologized to us more than once for taking so, so long and you have to deal with that. But I think it's also an opportunity because from our experience being flexible and let's name it customer oriented is a great advantage and a big plus compared to others. As a small company you have to be very flexible and I would say you are also expected to be, and that's sometimes a challenge and often an advantage, I guess.

To go to the core of that question, I mean obviously there are the politics, there are the slowness of larger companies, but do you think that ANSPs and airports should basically take more chances on smaller companies? We often see call for tenders for things that smaller companies could do, but they require five references in the last six months to put that a bit to an extreme and there are these kind of obstacles. So do you think smaller companies would deserve a fairer chace from bigger customers?

There are good reasons for especially ANSPs, other companies within the industry to have a look at those smaller companies. And I think the topics I mentioned or the things I mentioned are good examples for the advantages working with smaller companies, I think they're likely faster, less expensive of course and more motivated because from our personal perspective we also do projects because we really like what we do. Of course we like to generate revenue, but it's not the only reason we don't have to satisfy internal goals, but we like to be part of something interesting which has a result, has a real result. And this goes for most of the smaller companies I know of. They like to deliver results and solve problems. And this is a great opportunity I think to give, or a reason to give the smaller companies a try. But on the other hand, I can understand the concerns of the well-known bigger players in the industry. I think the smaller the company, the more it is about the people involved and of course they should have a closer look at the people involved in the companies. Maybe it's a fit, you have to work closely together. Maybe it's not a fit. This is something where you should have a closer look when thinking about that. But the barriers you mentioned, yeah, most of the time they just make it not possible, make it impossible to even get in touch. And this is something I would love to see getting changed.

Totally agree with that. I mean that's something we see in our job each and every day. So thank you for that and for the openness. And Julian, there is no way you can live today without answering our final question, what changes do you see for ATM surveillance and ATM in general for the next 5 years and also for the next 50 years?

To be fair, this question, so I had some time to think about it and it was an interesting journey for me. So thanks for the inspiration. It was interesting to have a deep thought on that. Well, it's a huge difference between the situation in 5 years and 50 years, of course. We know that processes and aviation, it takes some time and there's no quick transformation, which is also a good thing for the most part because the main reason why aviation is so safe is, I guess one of the reasons, is that we are working with proven systems. We don't just try something before we know that's a good idea and it's proven to be reliable. So for example, I think that still in 50 years we will still have human pilots for example. So I don't believe the stories of having just robots and computer systems.
Lemme start with the five years perspective. I would say speaking of surveillance, we will have a better ADS-B integration. Looking at the United States for example, they are several steps ahead looking at general aviation for example, they have the ADS-B equipage as a mandatory thing to have. And I think we will see more and more smaller aircraft being equipped with ADS-B transponders, which is a good thing, also for safety. I'd say that we will have less terrestrial navigation aids. Flying myself when I look at the charts every year, every year I see NDBs disappearing for example, or VORs. They so expensive to maintain and we see that whether or not absolutely necessary they're being dismantled or shut down and I think this process will continue in the next years. Yeah, the third thing that came to my mind is this whole topic of drones, of commercial drones, UAVs.
We see that this topic is really interesting because we are getting asked about drone surveillance actually all the time. And there isn't any strict standard yet like a strategy how to integrate the drones safely into our existing procedures. But the pressure's on and yeah, I'm quite confident that within the next five years there will be some kind of strategy, how to actually deal with this kind of drone operations and these new members of the aviation world. The long distance outlook. And when I look at the longer distance outlook for 50 years from now, I will be in my mid to late eighties then, and I will probably laugh at my statements from today, but I would say that artificial intelligence will play a bigger role in ATM. And I believe that we won't have the classical air traffic controller anymore. I would say we could exchange air traffic controller with air traffic manager, who is AI supported because reducing the human factor will of course be important to address the increasing traffic while maintaining safety.
And AI will play a big role I think when it's proven, when we have more experience with it, and it's going to be an interesting time. And I cannot imagine having, for example, AM voice communication as a primary channel for air traffic control. Maybe we will have a few more guard frequencies and that will be it. So datalink has to be the future. And I could also imagine that we see more space-based systems for data exchange. Another topic that came to my mind is integration of say, new space operations because we see that more and more companies are building launching platforms and like to have some kind of access to space, but we yet have to integrate space traffic into air traffic. And as of now, I don't know about any system protocol or strategy on how to integrate spaceships or carrier systems into our existing ATC systems or the ATM in general. So if you have space operations on a regular basis in a dense airspace, for example in Europe, you will have to find a solution on how to enable this kind of operation without closing down or restricting huge areas for the general air traffic. Yeah, I can imagine this being the big issue in the future, but not for the next five years.

Julian, thank you very much for being our guest today. Once more, your company is Skysquitter. Your website is and we will put link to your LinkedIn profile as well to the website in the episode notes. So if any additional wants to know more and get in touch with you, they know how to do that. Thank you very much.

Thank you Vincent. And yeah, we are looking forward to any kind of discussion and new cont. Have a great day.