| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a detecting device preventing saturation of a reception signal while suppressing an increase in a cost and a circuit scale. <P>SOLUTION: A reception signal monitoring unit 142 reads a reception signal according to sea bottom depth from a memory 17 to monitor a saturation state. For example, the reception signal monitoring unit sequentially reads reception signals of the prescribed number of samples from a reception signal corresponding to a depth substantially several samples shallower than the sea bottom depth and, when a maximum value of the samples reaches a saturation level or approximates to the saturation level, determines it to be the saturation state. When the reception signal monitoring unit 142 determines that the reception signal is in the saturation stare, a transmission condition setting unit 145 changes the conditions of the transmission signal. More specifically, the transmission condition setting unit 145 sets, to a transmission circuit 13, to lower the output of the transmission signal from the next ping, thus preventing the saturation of the reception signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
