Patent attributes
A method of radar detection of targets in an environment, comprising cyclically obtaining a detection profile that associates with each position in the protected area an amount of radar signal that has been reflected, and detecting targets from the detection profile in different modes. A base mode is used for a first series of cycles and is insensitive to motionless targets and sensitive to dynamic targets that move between different locations in the protected area. When the base mode detects a target, two additional modes are started, which are active in different areas. In first areas, a fine movement detection mode is used, which also neglects motionless targets and may be more sensitive than the base mode. In second areas, a presence mode detects both dynamic and motionless targets. When neither the presence mode nor the fine movement mode detects any target for a sufficient time, no people in danger are deemed to be present in the area and the base mode may be restored.