Indoor surveillance is becoming valuable. It can help secure vulnerable individuals, such as the growing numbers of elderly people living alone. These systems can spot when people fall or do not move at all, they can detect intruders and provide peace of mind.
But this type of surveillance does not always work and can also be intrusive. Video camera images can be hard to interpret when human bodies are partially occluded or when the light is poor. And few people want surveillance cameras in places like bathrooms and bedrooms.
A better option would be a non-visual way to monitor indoor settings. But while radar and lidar systems can be effective, they tend to be too expensive for most budgets.
