| 摘要 |
PURPOSE:To also detect an object out of a specific range while detecting the object in the specific range, by always covering the specific range while respectively shifting the transmitting and receiving beams of a transmitter receiver at specified azimuth angles every when said beams are transmitted and received. CONSTITUTION:A transmitter 1 sends a transmission signal to a radio transmitter 4 through a transmission and reception change-over device 2. This transmission and reception change-over device 3 includes a specified range forming 30 deg. angles left and right on the basis of the advance direction of the signal and changed over by a transmitting and receiving controller 3 so that transmitting beam ranging from left 120 deg. to right 30 deg. is formed so as to be able to search until 90 deg. in the left outside thereof. When transmission is finished, the transmission and reception change-over device 2 is changed over in connection. A receiver 5 receives an echo sound and a signal is sent to a receiver 6 through the transmission and reception change-over device 2. In the next transmission timing, the transmitting and receiving controller 3 controls the transmitting beam so as to rightwardly shift the same 30 deg.. Hereinafter, said beam successively advances at a 30 deg. step and, when advances until right 120 deg. from left 30 deg., it is leftwardly shifted at every 30 deg.. |
