# The Development of an Advanced Air Mobility Flight Testing and Simulation Infrastructure
## 1 Introduction
Furthermore, technological European research for RPAS in ATM (TERRA) aims to design an architecture to operate in very low level (VLL) airspace safely by properly using ground-based technologies and infrastructure [15]. The proposed architecture's purpose is to enhance the utilization of U-space services. Furthermore, the \"clear air situation for UASs\" (CLASS) project creates a basis for surveillance technology usage in the U-space [16] and the \"drone critical communications\" (DroC2 om) project focuses on a new command and control data link architecture [17]. U-space services are one of the core components for enabling the AAM. There are also research efforts on the development of such services. One of them is the \"U-space initial services\" (USIS) project, which aims to test U1 and U2 level services such as flight planning management, e-identification, tracking, and monitoring through live demonstrations [18]. As a basis for services dealing with separation, the \"defining the building basic blocks for a U-space separation management service\" (BUBBLES) project defines a U-space separation management system to be used in strategic conflict resolution and traffic information [19]. Moreover, the development and demonstration of new approaches for strategic and tactical level separation management are explained in projects such as \"U-space separation in Europe\" (USEPE) [20], \"a unified approach to airspace design and separation management for U-space\" (Metropolis 2) [21], and \"tactical instrumental deconfiction and in-flight resolution\" (TINDAIR) [22]. Demandcapacity balancing by considering risk assessment and social adoption based on noise and visual pollution is dealt under the \"demand and capacity optimization in U-space\" (DACUS) project [23]. Performances of some of the pre-flight and in-flight services through various use cases are tested in the \"proving operations of drones with initial UTM\" (PODIUM) project [24]. Similarly, in the safe and flexible integration of advanced U-space services for medical air mobility (SAFIR-Med), various U-space services are tested, focusing on medical services with UAM [25]. Another U2 service, geofence provision, is extensively covered in the \"geofencing for safe and autonomous flight in Europe\" (GEOSAFE) project, where the geofencing capabilities at different levels are tested through demos [26]. Another project that shows the importance of one of the U-space services is the \"ATM U-space Interface\" (PJ34-W3 AURA), which sets the required guidelines and validates ATM and U-space integration by the help of a developed collaborative ATM/U-space interface, a U3 level U-space service [27]. For the development of an information/data flow architecture, there are several projects, known as \"the information management portal to enable the integration of unmanned systems\" (IMT-PETUS) [28] and the \"drone European AIM study\" (DEAMS) [29]. These projects' purpose is to define the required data flow between stakeholders and develop a proper information management system. Finally, the \"integrated common altitude reference system for U-space\" (ICARUS) project proposes a common altitude referencing system and new services related to that issue, such as a vertical conversion service, a vertical alert service, and a real time geographical information service [30]. Security challenges of the U-space concept described in the \"integrated security concept for drone operations\" (SECOPS) project [31]. Regarding integration, a demonstration was conducted under the \"demonstration of multiple U-space suppliers\" (DOMUS) project, where the federated architecture through multiple service providers along with U-space services such as strategic and tactical deconfiction was tested [32]. In the \"Gulf of Finland U-space\" (GOF USPACE) project, a large scale demonstration aimed to show the interoperability between ATM and U-space together with micro-services provided by multiple U-space service providers (USSPs) through a flight information management system [33].