Abstract: A method for monitoring large surface areas. A thermal camera and an electromagnetic radar are rotated about a vertical axis to scan the area. The area is divided into sector-like surface elements. Monitoring criteria are established for each of the surface elements. Movements in the surface area being monitored are detected by the radar. The thermal camera is used to detect objects different, in temperature, from their surroundings. Detected objects are located in a surface element and identified in accordance with the monitoring criteria using at least one of the radar and thermal camera.