Developments for EGNOS V3 are underway at the European Space Agency
Last year, you and your team received the European Innovation Award from the European Patent Office for the signal design of the European satellite navigation system Galileo. Could you explain it our readers about the innovation by you and your team?
The team developed an innovative spread spectrum technique that creates a new single waveform called Composite BOC (CBOC). This signal will allow high-end receivers to compute accurate position and time and still be backward compatible with older and lower-end receivers (using e. g. BOC(1,1) on L1).
In addition, a modulation technique was developed that allows efficient transmission of four navigation codes in two adjacent frequency bands. This signal improves signal accuracy and saves satellite power. The modulation technique is called Alternative BOC (AltBOC) and is one of the enablers for GALILEO to offer an incredible enhancement in accuracy and performance (on E5a+E5b) while enabling interoperability with the GPS L5 signal (Galileo E5a), an enhanced signal with several users like aviation.
In general, the signalling technologies developed by the team enables compatibility (no interference with other GNSS sharing the same frequency spectrum), interoperability (a receiver can use signals coming from different GNSS) and better performance (more accurate positioning is possible).
You have been long associated with Galileo and EGNOS project in various capacities? How satisfied you are with their present status, progress and direction?
Developments for EGNOS V3 are underway at the European Space Agency for the first worldwide dual-system (GPS and Galileo) dual-frequency (GPS L1/L5 and Galileo E1/ E5a) navigation augmentation system. This will be a major innovative step when available around 2023.With the next launch of four Galileo satellites in 2019/20 will be the full constellation Galileo available. Developments for the second generation have started. A lot of people, especially our politician in Europe, were complaining about the long time in building-up Galileo. However, if we compare the time our US colleagues needed for GPS, namely about 23 years, with that of Galileo, about 16 years (between 2004 and 2020), then we can be satisfied.
This is a world of multi-GNSS systems. What advantages do you see about this scenario?
In fact, there are many advantages for the user being able to track four global and two regional satellite navigation systems (although the gain in performance of more than three GNSS is marginal). For example, with multiple Receiver Autonomous Receiver Monitoring (RAIM) we get a more secure PNT solution and can mitigate interferences, jamming and spoofing. Through interoperability between the different systems we can use a simple GNSS receiver. On the other hand, it creates competition between the various systems by the free market (and not by politics). There might be also disadvantages having more and more satellites transmitting on the same frequency. The internal noise is increasing which could create problems for receivers in acquisition of those signals.
Many countries plan GNSS systems primarily because of defence and security needs. Do you think that this may trigger a race with more countries joining in? What would be the implications?
There is no doubt that GNSS is nowadays a modern tool or even a “must” in defence. Considering the protection of the critical infrastructure of a state and the national security, it is understandable that many countries (with no alliances and corresponding agreements) want to have their own satellite navigation system.
The critical issue, however, is the following: Two decades ago we were convinced to avoid the misuse of a GNSS by third parties (in times of crisis) or terrorists by using various clever modulations and encryptions. Meanwhile we know that only high signal strength, in other words more power, can mitigate/avoid that problem. This may lead to larger and more costly satellites. The power race in future leads perhaps not to a favourable situation for the civilian users (although we have ITU regulations).
With increasing dependence on GNSS, how do you perceive the threats like interference, jamming and spoofing?
In fact, these are the challenges of GNSS/RNSS in the next years. However, we can do more. On the system evolution side, more secure and flexible signal generation and appropriate payloads have to be developed. For the user segment, the GNSS receiver, the same holds. Various efforts on the software side are possible, like multiple RAIM and interference, jamming and spoofing detection and mitigation algorithms, etc. On the hardware side I like to mention the chip-scale atomic clocks, the inertial navigation system on a chip and appropriate antennas.
What is your opinion on GNSS back-ups?
GNSS is no sole solver for each application. Of course, we have now many global and regional satellite navigation systems which can control each other. However, there are many other (safety-related) applications which require additional sensors and a sensor fusion.
How do you think the GNSS positioning technology can take advantage of other positioning technologies?
I continue where I stopped at my response to the last question. 5G wireless networks and technology is expected to be a new mobile revolution in the next years and will cover new use cases and exploiting new frequency bands, ranging from low data-rate for narrowband Internet of Things (IoT) to ultrafast enhanced broadband exploiting technologies such as millimeter waves, small cells, etc. We have to think how to complement GNSS by 5G wireless technology.
Many LEO communication systems with hundreds or even thousands of micro-satellites will be built up in near future, see e. g. OneWeb, Iridium NEXT and SpaceX Starlink. Instead of ignoring them, we also have to consider, how we can use these systems for navigation in order to improve our GNSS PNT solution.
What influences you envisage in satellite navigation in the near future given the advancements in the field of AI, Autonomous Vehicles, etc.?
Artificial intelligence and robotics see a hype nowadays. In satellite navigation we are only at the beginning of taking advantage of these technologies. Given the long time to build navigation satellites and a corresponding system, we might become victims of a successful long-living satellite navigation system and the need to guarantee backward compatibility for decades.
Therefore, in the evolution of the satellite navigation systems, a high degree of flexibility in signal generation and payload capability changes is an absolute need. This holds also for the user segment, the satellite navigation receiver. However, I remember what a colleague once said to me: “The new applications and innovation in satellite navigation are not limited by technology, only by our imagination…”. Thus, I trust in our young and bright colleagues to get the innovative imagination!
You had a long association with academia. Given the pace of technology evolution, would challenges you see for the academic community? Where is now your main interest and activity?
I am presently chairman of the Executive Board of Munich Aerospace e. V., a non-profit company having as shareholders the Technical University of Munich, the University of the Armed Forces Munich (Bundeswehr University), the German Aerospace Center (DLR Oberpfaffenhofen) and Bauhaus Luftfahrt, a “think tank” of aviation, situated at the Ludwig- Bölkow Campus near Munich, in the vicinity of aerospace industry like Airbus, Siemens and IABG. Our mission is to bundle all competencies in the field of aeronautics including satellite navigation in the greater area of Munich.
Munich Aerospace is based on the expertise of numerous professorships in the field of aerospace in the Munich area, which are contributing to each other. Interdisciplinary combination results in a unique density of benefits and outputs. Munich Aerospace is promoting the education of young academics in strong cooperation with the universities, research institutions and industry and is connecting the partner’s research and development.
This is made possible by engaging in four main fields of work: Promotion of interdisciplinary research alliances, providing connected educational offers, organization of the Munich Aerospace Graduate School, offering a scholarshipprogram. This is where I see the academics should go: not working alone but bundling the forces by making alliances with other appropriate partners from universities and industry.
Our newest development of Munich Aerospace was quite recently the built-up of a Global Aerospace Campus consisting presently of seven regions over all continents with the lead of Bavaria. The goals are the same like the ones of Munich Aerospace: a tight cooperation in teaching and research in aerospace. For more information see www.munich-aerospace.de
What impacts do you think Brexit may have on Galileo?
We see already the first impacts of a coming Brexit in Galileo. The Galileo Security Centre in United Kingdom was transferred to Spain. Galileo is a European system, therefore the Galileo Public Regulated Service (PRS) will be no more available for UK. Most likely British industry will not be allowed to participate in the further development of Galileo. Negotiations are still going on, but it is a pity that the UK likes to leave the European Union…
We have heard voices in the press that the UK intends then to build-up its own satellite navigation system. Can we believe that?
We will see in spring 2019 what happens, how the Brexit looks like.