The GATEMAN project is a research project focused on proving a novel concept for integrated GNSS interferences air navigation threats management, aiming at, on the one hand, their detection and localization and, on the other hand, their mitigation, either to keep GNSS navigation operative or, if that is not possible, to revert to a cost effective alternative technology (5G) that is able to support GNSS-based approaches.
The management of these GNSS threats (namely jamming and spoofing) would be based on existing aircraft antennas (i.e. no need of beamforming nor directional antennas). Besides, additional hardware (1 antenna and data processing board) is required on-board the aircraft, but the target of GATEMAN is minimizing the devices and therefore the installation cost. Considering the software, the algorithms implementing detection and localization have been: defined (based on existing literature with improvements to overcome the restrictions imposed in GATEMAN), implemented in post-processing and verified in laboratory conditions.
After the successful verification of the algorithms, a demonstrator (i.e. prototype) was elaborated to complete open-field experiments. The demonstrator consists on a vehicle where the 3 antennas are installed with the suitable baseline, including the recording hardware too (signal acquisition board and GNSS receiver). Open-field experiments were defined as a scale-down on-ground representative scenario, where interference signals were radiated and the demonstrator was moving in the affected area. The raw data recorded during open-field experiments was post-processed with the detection and direction-finding algorithms. After analysing the results, some issues were identified and improvements were suggested to achieve the functionality expected.
In addition this concept of interferences threats management defines an operational mode in which a Ground Facility would be involved, aggregating the information received from the aircrafts and providing a better estimation of the localization of the source and the denied GNSS-service volume. In addition this Ground Facility has the purpose of raising alerts when interfering events are confirmed, and shared with ATC the volumes without GNSS service due to localized interferences.
In addition to the novel concept of GNSS interference management described above, and as a complement to mitigate the effect of GNSS interferences, GATEMAN project has evaluated mitigation techniques at signal-processing level (spoofing monitoring) to enhance the robustness of GNSS positioning against spoofing attacks. Besides GATEMAN has evaluated alternatives positioning technologies (A-PNT) based on 5G to obtain navigation during GNSS jamming events.
