Martina Stehlikova, Honeywell, is the coordinator of Project P9.21, which received the “Best-in-Class” award from the SESAR Joint Undertaking at a ceremony in Madrid on 5 March. The project was recognised for the considerable work it undertook in defining options and developing a framework for airborne ADS-B performance evaluation, which is now accepted by the global SESAR community and is being used by other programme projects. In this article, Ms Stehlikova describes the impetus of the project and benefits that it will bring.
What was the impetus of the project (What is automatic dependent surveillance-broadcast (ADS-B)/Why was there a need to evaluate ADS-B performance)?
The ADS-B(Automatic dependent surveillance-broadcast) is one of enablers for the future ATM. With expected growth of the traffic in future and based on the fact that current 1090 MHz frequency on which ADS-B operates is used by other systems, growth of interference is expected. That might lead to degradation of the system performance required by current and future applications. The main impetus for the project was to investigate ways of how to ensure use of the link in order to accommodate the abovementioned future traffic without any changes to the link itself. We have investigated that for the system to be backward compatible the solution lies on improvements on the reception side, i.e. developing mitigation techniques that can decode ADS-B messages in high interference environment- which we have done within the project.
Describe the work of the project and its results?
The work was divided into three phases. In first phase, we assessed current link performance and identified potential issues that lead to the system performance degradation. A part of this phase was collecting requirements of the current and future applications that use ADS-B information as the main source. The second phase was focused on selecting possible mitigation techniques that can improve reception of the ADS-B information, taking in account its performance and also the impact on the aircraft installation, cost and complexity of the solution. In the third phase, we verified the functionality of the solutions via modelling and simulations both on receiver level and on environmental level. The results show that project’s effort was successful and the selected mitigation techniques do increase performance of the ADS-B receiver. Currently we are approaching the end of project by implementing and testing selected mitigation techniques in the laboratory mock-up.
What is the value of conducting such an R&D project within the SESAR programme?
The added value of SESAR programme is the opportunity to cooperate with industrial partners and research centres all over Europe. On the input side, such a cooperation leads to understanding requirements on the systems for future applications created by other elements in ATM research and in terms of output, it enables to build the proposed improvements in a way that they are consistent and compatible with each other. To give an example, in case of SESAR 09.21 I would emphasise cooperation with project 15.1.6, which was investigating the congestion of the frequency band. Results of this project proved that improvements on reception side are needed to use the ADS-B in mid and long-term timeframe. And on the other hand, results of 09.21 project are being further utilised by project 09.22 which looks at the ADS-B link in a mid-and long-term time perspective and researches if any adjustments to the link itself are needed. This synergy would not be possible for a stand-alone project.
How do you believe the results of the project can serve future ATM research and development, and more broadly air transport?
The results of the project aim to support development of new future surveillance applications, where information broadcasted by ADS-B is enabled. As growth of traffic is expected in the future, the ADS-B will be one of the key systems supporting the new applications that will allow optimisation of the air traffic. Additionally, the project results will be implemented in a hybrid traffic collision avoidance system (TCAS) currently being developed, where they will contribute to providing higher integrity information.