| 摘要 |
PURPOSE:To obtain a sonar which can accurately indicate an object to be detected, particularly, the sea bottom, by accurately correcting the attenuation of acoustic energy when the energy is propagaed in the water. CONSTITUTION:Ultrasonic detecting pulse signals are produced by a transmitter 1 and radiated in the wafer from a transmitter-receiver 2. Reflected waves from an object to be detected, such as the sea bottom, etc., are caught by the transmitter-receiver 2 and supplied to one input terminal of a multiplication amplifier 12 after they are amplifier at a preamplifier 3. To the other input terminal of the multiplication amplifier 12 the output signal of a control signal generator 5 expressed by 10(3+a).log r (where, a is 1<=a<=2 and r is the detecting distance) is supplied. The multiplication amplifier 12 performs multiplication on both the input signals and supplies a reflected wave signal, on wich attenuation correction is performed, to an indicator 6 which displays the signal. |
