This PhD thesis introduces methodologies for developing high-fidelity, tool-independent ray tracing-based RADAR and LiDAR sensor models for scenario-based testing. These models are created as functional mock-up units (FMUs) using the standardized open simulation interface (OSI) and functional mock-up interface (FMI), integrated into a co-simulation framework of commercial and open-source software, showcasing their performance and exchangeability without intellectual property (IP) infringement. The FMU models include the signal processing toolchain, address sensor imperfections, and consider environmental conditions. They are validated at the raw data level and the detection level.