INTEGRATED COMMON ALTITUDE REFERENCE SYSTEM FOR U-SPACE

Project Information

ICARUS

Grant agreement ID: 894593

DOI

10.3030/894593

Project closed

EC signature date 23 April 2020

Start date 1 May 2020

End date 31 July 2022

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 1 385 286,25

EU contribution

€ 1 144 587,50

Coordinated by

E-GEOS SPA
Italy

Periodic Reporting for period 2 - ICARUS (INTEGRATED COMMON ALTITUDE REFERENCE SYSTEM FOR U-SPACE)

Reporting period: 2021-05-01 to 2022-07-31

Summary of the context and overall objectives of the project

ICARUS project has the ambition to propose an innovative and feasible solution to address the novel challenge of the Common Altitude Reference inside VLL airspaces with a GNSS based approach for the vertical common reference and the definition of a new U-space prototype service for altitude transformations for UAS - Manned aircraft common reference, tightly coupled with the interface of the existing U-space services (e.g. Tracking, and Flight Planning services). Finally, the Terrain Model information above the ellipsoid datum used in the GNSS receivers, including Ground obstacles information, will be also an important element of the study for UAS- Ground obstacles separation. The concept will be validated in a mixed real and simulated environment.
Traditionally in manned aviation, the acknowledged method of determining the altitude of an aircraft was based on pressure altitude difference measurements (e.g. QFE, QNH, QNE, FL) generally referred to a common datum defined with the ICAO standard atmosphere (ISA);
The UA flights superimpose a new challenge in fact, the possibility for n drones to take off at n different places would generate a series of n different QFEn corresponding to different heights of ground pressures referred to the local (take-off) “Home points”.
The consolidated approach is therefore not feasible for a large number drones and new methodologies and procedures shall be put in place.
Due to these reasons the airspace actors can potentially become users of the new U-space ICARUS service, which main aim is to provide a height transformation service from a geometric measurement to a barometric reference system and vice-versa.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

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.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The ICARUS project has been able to connect two different worlds, ATM and UTM, through its Vertical Conversion Service. For the first time, UAS and manned aviation are able to fly in the same airspace in full awareness of each other’s vertical position, thus ensuring that vertical separation standards can be met.
Additionally, the ICARUS VALS algorithm alerts drone pilots to the proximity of ground obstacles. This could also be applied to manned aviation in future, enabling safer operations of HEMS and other state aviation in low-level airspace

The ICARUS project has shown the problems associated with performing many heavy calculations simultaneously. At present, only five conversion calculations can be performed every second. In areas of high traffic density, this could prove to be insufficient.

Despite all the inconveniences of the pandemic and the restrictions it has imposed on physical meetings, interaction between ICARUS team members has been excellent. Tools for remote working have enabled several meetings each week that have facilitated understanding of each partner’s ideas by the whole team and a rapid arrival at common positions. The result of this is that project team has worked closely together as one harmonious whole with excellent collaboration, enabling very efficient and focused progress towards the project goals

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