A-PNT - LDACS analysis
- SJU reference # PJ.14-W2-81c /Release 10
- Status In the pipeline
L-BAND BACKUP IN CASE OF SATELLITE SIGNAL OUTAGE
This Solution was formerly part of PJ.14-03-04-W1
Satellite signals from GNSS constellations, like Galileo, enable aircraft to follow precise flight paths and take advantage of PBN navigation procedures. Extended periods of signal interruption, for example as a result of signal degradation or satellite outage, can impact flight efficiency. SESAR is researching ways to maintain navigation performance during long-term signal disruption through the use of L-band digital aeronautical communications system (LDACS).
The candidate solution further studies LDACS as a complementary system for current navigation infrastructure, taking advantage of its development as a primary communication system. LDACS is one of most suitable candidates as it can be easily deployed with distance measuring equipment (DME) and is a driver for navigation infrastructure rationalisation, capable of meeting RNP0.3 requirements.
This candidate solution further examines ways to integrate inertial and terrestrial ranging sources using sensor fusion technology. It proposes a new approach to GNSS inertial integration based on system-level modularity. This is achieved by computing the aircraft position as the weighted sum of position estimates coming from different systems. Modular Integrity enables a range of sensors and systems to be incorporated seamlessly into the aircraft navigation solution and can support a hybrid mix of navigation technologies and wide geographic coverage. This availability of multiple geographic measurements is crucial to integrity which is based on redundancy.
The maturity of the LDACS system for both ground and airborne applications will determine maturity of this solution.
Improved flight efficiency