| 摘要 |
PURPOSE:To lower detection level down to the minimum required level, expand the searching range of an underwater sailing body and obviate error detection by providing a detection level setting circuit which is capable of setting the detection level with time. CONSTITUTION:Input signal level IPS is included with reverberation sound and sailing noise besides the reflected sound from the target. After this input signal is amplified, it is changed over by an input multiplexer MPX at each minute time and is inputted to a memory circuit MRY, where the input signal sampling level at the part sampling time and the sampling level at the current sampling time are averaged and stored. A detection level setting circuit DLS superposes the fluctuation component DELTAL of the level on the averated sampling level MV from the memory circuit MRY and sets the detection level DL then outputs the same through an output multiplexer MPX2. |
