The ICARUS solution to these problems is based on U-space services.
The ICARUS project results are related to the study and implementation of new services as well the improvement of existing services:
VCS (Vertical Conversion Service): provides automatic translation between barometric height and GNSS altitude (i.e. conversion from a barometric reference system to a geodetic one or vice-versa);
VALS (Vertical Alert Service): Alerts drones and manned aviation over the common geodetic reference system about the current vertical distance to the ground (or other drone traffic), when such a distance becomes too small.
RGIS (Real Time Geographical Information Service): provides accurate cartography and 3D DTM / DSM of ground obstacles during the execution of a flight, to provide real-time information on the vertical distance to the ground, including above taller obstacles.
• GNSS monitoring service: provides real-time information regarding the drone position and the integrity of the solution achieved to the other ICARUS subsystems. At the same time, the service performs a check of the quality of the GNSS signal in the geographical area of interest, through the monitoring of the progress of the integrity parameters, providing a usability flag to the users.
• Meteorological service: provides pressures, temperatures, positions, and orthometric height data of a distributed network of ground weather reference stations. This data will then be exploited to calculate the QNH pressure value for that point, given a certain set of coordinates where an aircraft is flying. Weather Data Providers are needed for accessing the regional average QNH pressure values.
The outcomes of ICARUS suggest «corridors dedicated to UAS» inside U-space airspace (EC Regulation 2021/664) providing that a certain navigation performance is achieved, not only in the horizontal plane, but also in the vertical one
ICARUS results can be used as starting point for traffic schemas implementation for future projects helping on:
• A maximum Number of vertical corridors (layers) at VLL for the capacity assessment can now be assessed.
• MFMC GNSS Receiver could be recommended for UAS BVLOS operations in combination with VALS service
• Navigation Monitoring Service Should include CORS (Continuous Operating GNSS Reference station for RTK correction to UASs (identification of a new service provider)
• Proposal for the introduction of CARA (Common Altitude Reference Areas) where VCS (Vertical Conversion Service is expected to operate
• Standardization, best practice and calibration of barometric sensors and certified source on ground (trusted source GIS / METEO)
• DTM/DSM undulation references
• Need to add more data from land pressure stations to reduce the unknown error between real QNH Reference and calculated QNH reference (possible network of ”certified” baro sensors on drones?!)
• Certification of service provider,
• GNSS Integrity algorithms to be further investigated for real time application even with dissimilar technologies and cross check correlation
• Certification of GNSS receivers for UAS operations.
The Common Altitude Reference System proposed by ICARUS is a major element in the integration of unmanned aircraft into the Air Traffic Management system.
This exploratory research project points the way towards future work required for designing a robust vertical reference service.