The project delivered:

  • NAVISAS Alternative Positioning, Navigation and Timing (APNT) operational concepts for small aircraft aiming at improving the flight safety level, as well as the ATM performance and efficiency;
  • Feasibility study and limitations of such concepts and delivery of a set of specifications for NAVISAS components. This was supported by laboratory tests and analytical studies to validate the predictions of the performance and technology characteristics;
  • System architectures allowing integration of GNSS receiver with atomic clock, and share of subsystems between atomic clock and atomic gyro;
  • Proof of concept (TRL 2) for vision-based navigation assessed in real flight of a drone and SHARK's aircraft.

NAVISAS pushed atomic gyroscope technology up to TRL 3. Envisioned performances are promising and could challenge currently used high grade laser gyros. Several solutions at the system level have been developed to reduce the price of the entire IMU system combing 3 axis gyros, accelerometers, GPS /GALILEO /GLONASS and atomic clock for application in drones and ULA.

Another topic of interest was hybridization of multi-constellation multi-frequency GNSS coupled with high-grade INS. No real benefit could be seen from the use of multi-frequency receivers when compared GPS L1 signal, nevertheless they are a good backup mean in case of unintentional interference on one GNSS frequency. Multi-constellation GNSS tight coupling with INS is an suitable approach for scenarios with frequent GNSS outages and already used in commercial aviation. TRL 3 was achieved in hybridization of GNSS with INS based on atomic gyros.

MAC (TRL 5-6) improves the solution availability and accuracy when compared to crystal oscillator clocks. It could reduce the signal recovery time upon GNSS outage, allows clock to be coasted in critical situations of satellite visibility and provides better protection against spoofing (better spoofing detection). Nevertheless, at the moment, there is no GNSS receiver on the market that supports external clock source and copes with NAVISAS requirements.

Vision-based navigation have been tested in real flight and have proven its usefulness, only 1 - 2 % drift was demonstrated. This is a very cheap alternative navigation method when compared to any other relevant system.

NAVISAS documents:

This project has received funding from the SESAR Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 699387.