Periodic Reporting for period 2 - GATEMAN (GNSS NAVIGATION THREATS MANAGEMENT)
Periodo di rendicontazione: 2019-01-01 al 2019-12-31
GATEMAN addresses the problems generated by GNSS interferences (either jamming or spoofing) for the airspace users. The jamming interference may degrade or even disrupt the GNSS position on-board the aircraft with the corresponding impact in the operations (missed approach, diversion, ATCO extra work...). On the other hand spoofing interferences might mislead the navigation on-board the aircraft, provoking an integrity issue, which has more severe criticality than the consequences of jamming.
In order to mitigate the consequences of GNSS interferences, GATEMAN proposes and develops a set of mitigation barriers (MB):
- MB1. Integrated GNSS interferences air navigation threats management. The purpose of this barrier is to minimize the effect of interferences by reducing the time to deactivate it and by routing traffic to avoid volumes suffering interferences. This kind of management of GNSS interferences requires the detection and localization of any interference, which is done thanks to the installation on-board the aircraft of the suitable hardware and software. These components are designed to minimize the cost of retrofit and forward fit aircrafts because current omnidirectional GNSS antennas are used.
- MB2. Use of 5G as alternative mean of navigation in case of GNSS degradation during approaches, which is the most critical flight phase.
- MB3. Use of spoofing monitoring to mitigate the effects of spoofing at the GNSS receiver.
In order to mitigate the consequences of GNSS interferences, GATEMAN proposes and develops a set of mitigation barriers (MB):
- MB1. Integrated GNSS interferences air navigation threats management. The purpose of this barrier is to minimize the effect of interferences by reducing the time to deactivate it and by routing traffic to avoid volumes suffering interferences. This kind of management of GNSS interferences requires the detection and localization of any interference, which is done thanks to the installation on-board the aircraft of the suitable hardware and software. These components are designed to minimize the cost of retrofit and forward fit aircrafts because current omnidirectional GNSS antennas are used.
- MB2. Use of 5G as alternative mean of navigation in case of GNSS degradation during approaches, which is the most critical flight phase.
- MB3. Use of spoofing monitoring to mitigate the effects of spoofing at the GNSS receiver.
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.
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.
The capability of interference (jamming and spoofing) detection and direction finding on-board an aircraft, with minimal hardware upgrade, is possible. As this capability is the origin of the concept of GNSS interference threats management introduced in GATEMAN, we conclude that this new concept is feasible and its benefits should be considered. Nevertheless the performances of localization need to be evaluated with further experiments and analysis solving the issues mentioned before.
The term spoofing mitigation means removing the counterfeit GNSS signal to allow the receiver to track only the true GNSS signal. The algorithm analysed and evaluated in GATEMAN is based on ‘subspace projection’ and the results are promising, completely removing the spoofed signal in a wide range of scenarios. In addition, this algorithm is applied on each receiver individually.
The use of 5G NR (New Radio) for positioning purposes has certainly big prospects in terrestrial applications, particularly when using mm-wave bands (better accuracy and less coverage than cm-wave bands). The analysis in GATEMAN confirmed that the use of 5G cm-band navigation is limited to low-altitude operations (i.e. approach phase for commercial aircrafts), whereas mm-band is limited to close-to-ground operations (i.e. taxiing for commercial aircrafts, U-space…). Finally, the positioning methods evaluated (TDoA and AoA), needs to be improved to increase robustness and accuracy.
The term spoofing mitigation means removing the counterfeit GNSS signal to allow the receiver to track only the true GNSS signal. The algorithm analysed and evaluated in GATEMAN is based on ‘subspace projection’ and the results are promising, completely removing the spoofed signal in a wide range of scenarios. In addition, this algorithm is applied on each receiver individually.
The use of 5G NR (New Radio) for positioning purposes has certainly big prospects in terrestrial applications, particularly when using mm-wave bands (better accuracy and less coverage than cm-wave bands). The analysis in GATEMAN confirmed that the use of 5G cm-band navigation is limited to low-altitude operations (i.e. approach phase for commercial aircrafts), whereas mm-band is limited to close-to-ground operations (i.e. taxiing for commercial aircrafts, U-space…). Finally, the positioning methods evaluated (TDoA and AoA), needs to be improved to increase robustness and accuracy.