PURPOSE: To transmit a secondary wave having a sharp directivity toward right beneath a ship's bottom when a hull is rolling.
CONSTITUTION: As a wave transmitting system, the following parts are provided. A transmitting-timing controller 1 outputs a trigger signal T when a rolling angle θ of a hull 8 is zero. Transmitters 2 and 3 output transmitting-pulse electric powers P (F1) and P (F2) having two close frequencies based on the trigger signal. A parametric wave transmitter 4 forms the primary waves having two close frequencies based on the transmitting-pulse electric powers, forms the secondary wave B (F1-F2), which is the difference between the primary waves, based on the parametric effect and transmits the secondary wave to the sea bottom. As a wave receiving system, the following parts are provided. A wave receiver 5 receives the secondary wave BR (F1-F2), which is reflected from the sea bottom and returned as an echo R, and outputs the echo. A receiver 6 receives the echo and the trigger signal T, obtains the water depth value of the sea bottom and the outputs the echo. A recorder 7 records the water depth value and the echo.
JP2652999 | [Title of Invention] Active Sonar Device |
JPS51149058 | ULTRASONIC WAVE DETECTOR |
WO/2017/102990 | SYSTEM FOR MONITORING AND/OR SURVEYING CONDUITS |
JPS5848867A | 1983-03-22 | |||
JP53100268B | ||||
JPS6423755A | 1989-01-26 |