Urban Digital Twins (UDT) promise to improve city planning by providing a comprehensive and up-to-date digital representation of the real city. However, cities are complex systems involving diverse stakeholders with different interests and knowledge of various aspects of physical urban elements. Therefore, integrating, managing, and visualizing information from distributed sources is a common challenge in UDT development. Typically, UDT are implemented as distributed systems of systems that serve various applications by using diverse digital resources (sensor measurements, point clouds, virtual 3D city models and further geospatial data, spreadsheets, simulation results) across stakeholders. An essential and robust management system is needed to manage digital representations of physical urban objects in a distributed UDT. In response to these requirements, the Smart District Data Infrastructure (SDDI), a framework for use case-driven data management and data integration in smart cities, has been developed. Initially, the SDDI concept was developed and applied mainly to districts of large European cities. This paper addresses how SDDI can technically be implemented in smaller municipalities with their limited financial and human resources. In particular, we define a minimal ecosystem aiming at enabling smaller municipalities to implement beneficiary applications based on a distributed UDT. Furthermore, we discuss the role of the two SDDI core components, the SDDI catalogue and Virtual District Model (VDM), within the minimal ecosystem. Using the SDDI catalogue as an example, we describe how cloud-optimized open-source software can achieve a low entry barrier for deploying and operating an SDDI core component. As a proof of concept, we present use cases from 17 smaller Bavarian municipalities and discuss the deployment and application of the minimal ecosystem for a specific UDT use case.     «

Urban Digital Twins (UDT) promise to improve city planning by providing a comprehensive and up-to-date digital representation of the real city. However, cities are complex systems involving diverse stakeholders with different interests and knowledge of various aspects of physical urban elements. Therefore, integrating, managing, and visualizing information from distributed sources is a common challenge in UDT development. Typically, UDT are implemented as distributed systems of systems that serv...     »