November 22, 2022


The demonstration event took place at Unmanned Valley, Valkenburg, The Netherlands, on the 14th of September 2022 coinciding with the project’s second workshop. In this way, the workshop’s participants had the opportunity to witness the demonstration activities and the discussion was expanded to include the demonstration outcomes in addition to the overall outcomes and results of the project.

The demonstration trials were conducted on the taxiway of Valkenburg airfield, previously a naval air base, which now serves as a testing area for UAVs. The hardware used to demonstrate the traffic scenarios consists of:

  • Four Parrot Bebop 2 quad-copters fitted with custom autopilot firmware
  • Two computers: One computer was used to host Paparazzi UAV, a program that acts as an autopilot and interface between BlueSky and the aircraft. The other computer ran BlueSky, presented in the next chapter.
  • A wifi router to provide connectivity with the drones

BlueSky was used to design and simulate the demonstration scenarios of the decentralised, hybrid, and centralised separation management concepts, and as an intermediate agent for the Unifly platform demonstrations. To demonstrate the concepts, scenarios were created and then simulated using either the decentralised, the hybrid, or the centralised concept. The resulting trajectories were recorded as static scenarios. These static scenarios were used during the physical demonstrations. To facilitate the live event, BlueSky was modified to be able to interface with Paparazzi UAV and send commands to drones. Thus, the drones received their flight plans and commands from BlueSky, and sent back location information to display and log in the same format as the simulation data logs[1].

[1] The implementation of the demonstration code in BlueSky can be found with the following link:

In the Metropolis 2 project and during the trials, the Unifly system was used to serve as the UTM system and was adapted with the necessary adjustments in order that the demonstration could take place.

Following integrations and adjustments are the most important ones which are done in order that the Unifly system was configured to the test site and could serve as the U-space environment for the project.

  • Demonstrator environment

The Unifly system was deployed as a sandbox environment in Azure cloud to serve as demonstrator environment, in the form of an operator web portal and a supervisor web portal.

  • Legislation implementation and permission request flow

In order to correctly validate the drone operations, the demonstrator environment was enhanced with the needed legislation implementation. This legislation is in the form of validation rules which are set up to be valid in the area of where the demonstrator was carried out. Based on certain parameters of the operation and the available data at hand, the Unifly system will generate a validation result together with potential linked actions.

One linked action could be the fulfilment of a permission request, for which a permission request flow as implemented. From the operation details, the operator can send over the permission request as task towards the supervisor. The supervisor can manage the permission request and potentially approve the permission request via the supervisor portal.

  • Import of data

The Unifly system was enriched with the needed relevant data to make sure the scenarios could be carried out. Most important data which was applied to the system were:

  • Surrounding and on-site geozones: Public, military, HEMS airports and control zones
  • Temporary no-fly zones which could be managed via the no drone zone manager in the Unifly supervisor portal
  • U-space zone
  • The simplified Vienna street model which served as test city as constrained airspace
  • API Integration with BlueSky system

The most significant adjustment towards the system was the possibility to connect with the BlueSky simulator system of TUDelft in order to display the relevant information from the BlueSky system in the Unifly system.

In order to make the interface, Unifly shared the GCS (Ground Control Station) API which was used by TUDelft in the BlueSky Simulator. After the implementation of API, The Unifly system could receive and display the following data related to the different scenarios

  • The path operation area which was created on the BlueSky system
  • The initial drone positions and the updates of the positions resulting in the drone flight path
  • The updated operation areas in light of the executed scenarios
  • The position of other vehicles (for instance a helicopter) which were also created in the BlueSky system

This interface made it possible to display the executed scenarios in the flight view of the Unifly system, in which the drone positions were shown together with available geozone and airspace data resulting in full situational awareness. Next to this, it was possible to trigger the relevant collision alerting based on the vehicle positions as part of compliance monitoring.

Overall, the demonstration flights were conducted successfully, with 22 individual UAV flights from four real drones.

One important factor for the quality of execution of an outdoors demonstration involving UAVs is the weather. Weather conditions were nominal in the area during the demonstration flights, with no rain and low wind speeds. The wind direction was to the East with wind speeds varying from 0 to 8 knots and an average of 0.87 knots for the 14th of September in the area around the flights based on weather data provided by Wunderground.

Centralised Concept

Decentralised Concept

Hybrid Concept

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