| 摘要 |
PURPOSE:To cross a transmit and a receive wave beam easily by giving either of the transmit and receive wave beams an acute directivity angle in a pencil shape, and making the directivity angle of the other acute vertically and wide horizontally. CONSTITUTION:An ultrasonic-wave transmitter Z1 transmits an ultrasonic-wave signal from a point P in a direction theta1, and the transmit wave beam is set at the acute directivity angle in the pencil shape. An ultrasonic-wave receiver Z2, on the other hand, is installed at a point Q in a direction theta2 so that a reflected wave from a point R is received, and its directivity angle is acute perpendicularly and wide horizontally. Thus, the horizontal azimuth of the transmit-wave beam is set within the horizontal directivity angle beta of the receive-wave beam to receive the reflected wave from the point R easily. |
