Accurate human modeling for simulation is increasingly vital for design and placement of passive and active sensing systems. In this webinar, we present a methodology for modeling radar returns and shadowing from humans, including the effects of breathing and heart rate on micro-Doppler. We then present results from validation against measurements from NIST confirming the general approach, and discuss and demonstrate its application to relevant real-world scenarios such as micro-Doppler for in-cabin child presence detection and sensing in indoor and outdoor environments.