Future space operations, particularly the handling of large, interdependent fleets and constellations as part of space traffic management efforts, will depend to a large degree on data from ground-based sensors that provide space surveillance and tracking and space situational awareness (SSA). In order to ensure global coverage, these sensors will need to be designed as networks distributed across various geographical locations. This chapter presents an overview of the legal considerations of ground-based sensor architecture for future space operations. With a focus on the operational capability for SSA and space traffic management (STM), the chapter describes existing SSA networks and those under development. It highlights legal considerations in view of future multi-stakeholder cooperation and offers considerations on implications of sensor ownership, tasking, dual use, and data policy in collaborative efforts in SSA and STM.