| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably and highly reliably trace a plurality of individuals of hydrosphere organisms over a long period. <P>SOLUTION: A monitoring apparatus 100 includes a housing 120 with a watertight structure and an electronic circuit 144 arranged in the housing 120 and capable of respectively recording first and second signals outputted from first and second underwater microphones in first and second channels respectively. The electronic circuit 144 shifts frequency bands of the first and second signals to the low band side only by a predetermined frequency, digitizes the frequency-shifted first and second signals and records the digitized first and second signals in a hard disk or the like as signals of the first and second channels. <P>COPYRIGHT: (C)2013,JPO&INPIT |
