The sensing system in the cockpit can detect people and movements, and distinguish people from inanimate targets, thus helping to build a more accurate safety belt reminder and airbag deployment system. When the target weight exceeds a certain threshold, the weight sensor will trigger the safety belt reminder. However, the weight sensor cannot distinguish bags, boxes or wallets similar to the size and weight of passengers, while the radar sensor can easily distinguish the two. The airbag system can benefit from more accurate sensing. Radar can be used to identify whether the seat is a child or an adult. In case the airbag is deployed, the airbag can be adjusted according to the height of the personnel. More advanced features include estimating the heart and respiratory rates of both the driver and crew while driving. When integrated into the overhead console or roof, the functional range of this sensor has covered all passengers, so that the application can predict the driver's fatigue or sleepiness status and activate the alarm. For applications that require higher resolution, such as detecting the posture of passengers or drivers, imaging radar equipped with millimeter wave sensors can achieve high-resolution occupant detection.