INTRUDER DETECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To enable an intruder detecting device to detect an intruder into a room without receiving any influence from the walls and furnitures existing in the room by comparing the state information on the installed location of a transmission-reception antenna and its vicinity when an intruder to be detected exists in the room with the premeasured state information on the location and its vicinity. SOLUTION: An intruder detecting device is provided with a transmission- reception antenna 105 which is installed to a closed intruder watching area, transmits a radio wave, and receives the reflected radio wave of the transmitted radio wave; an A/D converter 201 which digitizes the received radio wave; and an FFT processing section 202 which computes a frequency spectrum by performing FFT on the digitized radio wave. The detecting device is also provided with a peripheral state storing section 204 which computes and stores in advance the peripheral state frequency spectrum of the received radio wave in accordance with the peripheral state of the antenna 105 and intruder detecting means 203 and 205 which detect an intruder into the intruder watching area based on the comparison with a computed frequency spectrum with the above- mentioned peripheral state frequency spectrum.