This project is based on the principle of RADAR. This project has got a SONAR module mounted on a stepper motor . As the stepper motor rotates, SONAR module sends out ultrasonic waves and scans the room. So, if this project is placed in the center of a room, it can scan the whole area and the range of scanning depends on the SONAR module used. With a Polaroid 6500 series sonar ranging module, the range is about 6" to 35ft.
This product is intended to be used for security alert systems in a room / area devoid of any movements.