Future air navigation systems will feature international agreement on a plan for more efficient communication, navigation, surveillance and air traffic management (CNS/ATM), based heavily on satellite technology. The more dependent the global air transportation system becomes on GPS, the more vulnerable it is to disruptions in access to its signals.
Automatic Dependent Surveillance – Broadcast (ADS-B) In and Out is an essential capability within NextGen implementation plans. It is also featured in SESAR. GNSS and GPS services are essential for full ADS-B capabilities.
Combined capabilities, parallel functionalities (Galileo & GPS), and special frequencies resistant to jamming spoofing available within multi-mode receivers may be quite robust. (see RTCA documents)
Planned ADS-B coverage includes only those areas currently covered by radar. There are large regions of the airspace where there is no radar coverage.
ADS-B broadcasts are unencrypted and possibly vulnerable. (evidence, RTCA?)
- Changes to existing procedures in certain non-normal conditions to maintain adequate safety margins
- Exclusive reliance on single CNS technologies, raising questions about graceful degradation and redundancy.
- Jamming: Intentional interference or jamming, i.e. emission of sufficiently powerful radio frequency energy. This is either realized as emission of a signal close to the GPS spectrum or if more sophisticated as emission of a GPS-like signal. Civil receivers are vulnerable.
- Spoofing: Is the intended injection of false GPS like signal. The receiver will lock onto a legitimate appearing signal.
- Failure of CNS systems to communicate changes arising from dynamically reconfigured airspace
- Crippling effects of Coronal Mass Ejections (solar weather) on satellite electronics and ground infrastructure
- Impact of man-made space debris
- Degradation of radio/satellite communication: During solar events, some disturbance may happen on HF and satellite communications, which would have side effects on CPDLC, ADS-C, AOC…. However, line of sight VHF communication may not be impacted.
- Onboard system failure due to radiation: During a radiation storm, when striking a sensitive node, radiation may induce shortcuts, change of state, or burnout in onboard electronic devices. This phenomenon is called the “single event effect”. Its impact may vary a lot from unnoticeable to a complete failure of the system. This kind of failure may become more frequent in the future because modern electronic equipment is more vulnerable to radiation due to the smaller size of their devices.
- Radiation doses: During radiation storms, unusually high levels of ionizing radiation may lead to an excessive radiation dose for air travellers and crew. The dose received by passengers and crew is higher at higher altitudes and latitudes.
- GNSS based aviation operation: High-energy particles ejected by the sun may cause strong disturbances in the upper layers of the atmosphere, mainly in the layer called the Ionosphere. This layer is composed of charged particles and is particularly sensitive to the particles ejected by the sun. The GNSS radio signals emitted by satellites have to travel through this particular layer and, under severe disturbance, are strongly affected. As a result, unexpected position and timing errors can occur at the level of the user receiver. In extreme cases, the GNSS receiver can lose reception of the satellite altogether and the position can no longer be computed. As a side effect, GNSS-based surveillance applications may be unavailable. SBAS or GBAS augmented services, used for approach and landing, are more demanding in terms of accuracy and integrity than the En Route/TMA GNSS-based navigation. As a consequence, the safety monitors of those systems are also more sensitive to space weather events and the unavailability of these services would be more frequent.