Applications of a Web Direct-Access model integrated for underwater ultrasonic measurements in a tank

Target strength (TS) of fish is important in order to convert acoustic integration values obtained by acoustic survey into estimates of fish abundance. A large indoor tank has been used in underwater acoustics experiments such as measurements of the target strength pattern of fish. It was equipped with an electric flatcar for the purpose of loading and positioning an ultrasonic transducer. A TS measurement system loaded with a fish-suspension and rotating mechanism has been developed for a tank. Furthermore, a water level meter was constructed for the efficient operation of water supply or draining. A model for Web direct-access monitoring was newly designed on the basis of the concept that an operator could control a mechanical device using a Web browser via LAN. It was used in three systems, an electric flatcar, TS measurement system and a water level meter, to control and monitor remotely via a network. Applications of a Web direct-access model to these systems is introduced and described in detail. For 34 hours during water supply, water depth was measured successfully. Then monitoring operations by multiple PCs were evaluated widely via the Intranet or Internet. A calculation method of the residual needed time was suggested for the perspective of a finish time for water supply. Then, installation of a remote control terminal was required for efficient operation of an electric flatcar. A remote control system using a notebook personal computer has been developed with good cost performance.