071 - Technologies for Reliable Ambiguity Resolution (RAR) and Integrity in High Accuracy Positioning

071 - Technologies for Reliable Ambiguity Resolution (RAR) and Integrity in High Accuracy Positioning


High Accuracy requires usage of phase measurements, which are ambiguous measurements: ambiguities must be fixed to relate phase measurements to ranges.​
Phase Ambiguity Resolution is a stochastic process which needs a minimization search for the correct ambiguities which can require a very large search to find the correct solution: such a search is very time consuming, and the search space must be limited to avoid very long time processing, with consequent practical limitation in the reliability of the identified optimal solution.​ This limitation prevents performing integrity processing on high accuracy positioning because any feared event involving wrong ambiguity resolution or interruption of phase measurement would not allow to provide a boundary with a very high probability, as would be required by a reliable, accurate and precise positioning service.​ There is the need to improve the AR and precise positioning processes and make them reliable.

Objective: Apply the Artificial Intelligence (AI) to Ambiguity Resolution (AR) problem on the user side to increase the AR reliability, looking for approaches that focus on multi-frequency and multi-system, which do not necessarily follow the state of the art methodology for AR (float estimation + decorrelation + Integer Least Square).

Description of innovation/Tasks: 

  • Navigation signal ranging allowing reliable and fast ambiguity resolution in phase measurement​.
  • Solution for applying AI to AR to improve reliability of high accuracy positioning.
  • Review studies on integrity for high accuracy positioning, e.g. TDE Enablers of range-domain rigorous integrity for future safety-critical applications.
  • Review state-of-the-art of Ambiguity Resolution.

Expected output:

  • Data package (reports, algorithms, results, etc.) providing a complete understanding of achievable capabilities of ambiguity fixing and related positioning performances.