logo-network logo-network2 pixel-outer pixel

Augmenting Satellite Navigation Performance for Safety-Critical Aerospace Applications

In an era of significant air traffic expansion characterised by a rising congestion of the radiofrequency spectrum and a widespread introduction of Unmanned Aircraft Systems (UAS), Global Navigation Satellite Systems (GNSS) are being exposed to a variety of threats including signal interferences, adverse propagation effects and challenging platform-satellite relative dynamics.

Thus, there is a need to characterize GNSS signal degradations and assess the effects of interfering sources on the performance of avionics GNSS receivers and augmentation systems used for an increasing number of mission-essential and safety-critical tasks (e.g., wide area navigation and precision approach, experimental flight testing, and flight inspection/calibration of ground-based radio navigation systems).

GNSS signal deteriorations typically occur due to antenna obscuration caused by natural and man-made obstructions present in the environment (e.g., elevated terrain and tall buildings when flying at low altitude) or by the aircraft itself during manoeuvring (e.g., aircraft wings and empennage masking the on-board GNSS antenna), ionospheric scintillation, Doppler shift, multipath, jamming and spurious satellite transmissions. Anyone of these phenomena can result in partial to total loss of tracking and possible tracking errors, depending on the severity of the effect and the receiver characteristics.

GNSS augmentation can take many forms but all strategies share the same fundamental principle of providing supplementary information whose objective is improving the performance and/or trustworthiness of the system. Hence it is of paramount importance to consider the synergies offered by different augmentation strategies including Space Based Augmentation System (SBAS), Ground Based Augmentation System (GBAS), Aircraft Based Augmentation System (ABAS) and Receiver Autonomous Integrity Monitoring (RAIM). Furthermore, by employing multi-GNSS constellations and multi-sensor data fusion techniques, improvements in availability and continuity can be obtained. SBAS is designed to improve GNSS system integrity and accuracy for aircraft navigation and landing, while an alternative approach to GNSS augmentation is to transmit integrity and differential correction messages from ground-based augmentation systems (GBAS).

In addition to existing space and ground based augmentation systems, GNSS augmentation may take the form of additional information being provided by other on-board avionics systems, such as in ABAS. As these on-board systems normally operate via separate principles than GNSS, they are not subject to the same sources of error or interference. Using suitable data link and data fusion technologies, a properly designed and flight-certified ABAS could be a core element of a future GNSS Space-Ground-Aircraft Augmentation Network (SGAAN).

You can access our research article at: https://www.sciencedirect.com/science/article/pii/S037604211730163X

Print Friendly, PDF & Email

Latest News

Featured image
IEEE Distinguished Lectures on Avionics and Trusted Autonomous Aerospace Systems

Professor Sabatini's lectures focus on Cyber-Physical Systems (CPS) for trusted autonomous air and s...

Featured image
Professor Roberto Sabatini receives the Distinguished Leadership Award from Aviation/Aerospace Australia

Aviation/Aerospace Australia (A/AA) is a not-for-profit and independent association, with an overarc...

Featured image
Professor Sabatini named Scientist of the Year at the Australian Defence Industry Awards 2019

This award recognises a scientist that has delivered outstanding work for their organisation or inst...

Featured image
Space Traffic Management: Towards Safe and Unsegregated Space Transport Operations

  Within the atmospheric domain new-entrant platforms performing point-to-point operations will requ...

Skip to toolbar