A system used to monitor and control a pool using a visual light communication system is disclosed.

A receiving apparatus includes: M receivers configured to receive signals based on sound waves propagating in water; M FIR filters configured to perform waveform operation on the signals received by the receivers; a combiner configured to combine output signals of the M FIR filters; and a filter coefficient calculation portion configured to calculate a tap coefficient of the M FIR filters so as to reduce an error of the output signals combined by the combiner. The M FIR filters have a tap length that is shorter than a delay spread that is a possible range between a time of arrival of a direct wave and a time of arrival of a delayed wave of the sound waves.

A receiving apparatus includes: M receivers configured to receive signals based on sound waves propagating in water; M FIR filters configured to perform waveform operation on the signals received by the receivers; a combiner configured to combine output signals of the M FIR filters; and a filter coefficient calculation portion configured to calculate a tap coefficient of the M FIR filters so as to reduce an error of the output signals combined by the combiner. The M FIR filters have a tap length that is shorter than a delay spread that is a possible range between a time of arrival of a direct wave and a time of arrival of a delayed wave of the sound waves.

Disclosed herein are systems and methods for ropeless fishing. The ropeless fishing system includes a surface subsystem installed on a vessel and at least one submerged subsystem submerged in a body of water. The surface subsystem includes acoustic transceiver and acoustic transducer units, which are configured to generate and omnidirectionally transmit an acoustic interrogation signal into the body of water surrounding the vessel and to directionally receive acoustic reply signals. The submerged subsystems include a compressed gas source and an enclosed flotation bag in fluid communication and an underwater acoustic actuator-transponder unit configured to receive the acoustic interrogation signal transmitted by the surface subsystem and to transmit an acoustic reply signal into the body of water. In addition, the submerged subsystem is further configured to control the flow of gas between the compressed gas source and the enclosed floatation bag to facilitate recovery of the submerged subsystem.

Disclosed is an optical window cleaning device, including: a cleaning brush; and a wiper arm. The wiper arm includes a first link, a torsion mechanism, a second link and a wiper arm drive system. A second end of the first link is hinged to a first end of the second link. The cleaning brush is hinged to a first end of the first link, a rotation trajectory of the cleaning brush and a rotation trajectory of a hinge joint between the second end of the first link and the first end of the second link are both located in a first plane. A rotation trajectory of the second link and the rotation trajectory of the hinge joint are located in the first plane. The torsion mechanism provides the first link and the second link with a force that rotates the first link relative to the second link.

A visible light communication (VLC) system transmits and receives visible light signals across a VLC channel that includes an air-water interface. A transmitter may be configured generates and transmits a visible light signal across the VLC channel to a remote device, and a signal modulator controls the transmitter to generate the visible light signal from a digital transmission signal in accordance with a modulation setting. A receiver processes a remote visible light signal received across the VLC channel from the remote device. A signal demodulator converts the remote visible light signal to a received digital signal.

This optical communication device (1) is provided with: a plurality of light-receiving elements (11) configured to receive communication light, the plurality of light-receiving elements being provided so as to correspond to a plurality of channels; and a controller (15) configured to perform control to invalidate output from a light-receiving element that has received high-intensity light higher in light intensity than a predetermined value among the plurality of light-receiving elements.

This optical communication device (1) is provided with a plurality of light-receiving elements (11) and a plurality of optical fibers (12). The plurality of optical fibers each includes a light-incident end portion (12a) for communication light and a light-emission end portion (12b) for communication light. The plurality of light-emission end portions is each arranged near each of the plurality of light-receiving elements. The plurality of light-incident end portions is each configured to be capable of being arranged in a predetermined position in a predetermined direction.

The present invention relates to a fiber branch structure for spatial optical communication for transmitting information by emitting communication light. The fiber branch structure is provided with: a light emitter configured to emit communication light; a light emission controller configured to control the light emitter; an optical fiber configured to transmit the light emitted from the light emitter; a distributor configured to distribute the light, the distributer being optically coupled to an output terminal of the optical fiber; and an optical fiber group optically coupled to a plurality of output terminals of the distributor. According to the present invention, a communication area can be established without blind spots. That is, the fiber branch structure for spatial optical communication according to the present invention includes an optical fiber group optically coupled to a plurality of output terminals of the distributor. A communication area can be established more assuredly by such an optical fiber group, which prevents the optical communication from being interrupted.

The present invention relates to a fiber branch structure for spatial optical communication for transmitting information by emitting communication light. The fiber branch structure is provided with: a light emitter configured to emit communication light; a light emission controller configured to control the light emitter; an optical fiber configured to transmit the light emitted from the light emitter; a distributor configured to distribute the light, the distributer being optically coupled to an output terminal of the optical fiber; and an optical fiber group optically coupled to a plurality of output terminals of the distributor. According to the present invention, a communication area can be established without blind spots. That is, the fiber branch structure for spatial optical communication according to the present invention includes an optical fiber group optically coupled to a plurality of output terminals of the distributor. A communication area can be established more assuredly by such an optical fiber group, which prevents the optical communication from being interrupted.