A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is also configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly.

A frequency steered sonar element comprises a transducer element and a grating element. The transducer element presents a longitudinal axis and is configured to receive a transmit electronic signal and generate an acoustic wave with a frequency component corresponding to a frequency component of the transmit electronic signal. The grating element presents a longitudinal axis and is oriented such that a longitudinal axis of the grating element and a longitudinal axis of the transducer element form an acute angle. The grating element includes a first surface and an opposing second surface. One or more of the surfaces includes one or more grooves distributed thereon, the one or more grooves including first and second facets. The grating element is configured to emit a sonar beam in an angular direction which varies according to the frequency component of the acoustic wave.

A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is also configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly.

A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is also configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly.

A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly. The sonar data includes information indicative of vegetation present on a lakebed, seabed, or riverbed surface, the information being displayed on the topographical chart.

A sonar mapping system that includes a sonar transducer assembly configured for mounting on a watercraft, and a display configured to show a topographical chart of a body of water. The sonar mapping system further includes a processor coupled to the sonar transducer assembly and display. The processor is configured to create the topographical chart in real time, and to update the topographical chart in real time, based on sonar data provided by the sonar transducer assembly. The processor is configured to render the created or updated topographical chart on the display. The sonar mapping system has memory accessible by the processor and configured to store the topographical chart rendered by the processor, and to store the sonar data provided by the sonar transducer assembly. The sonar data includes information indicative of vegetation present on a lakebed, seabed, or riverbed surface, the information being displayed on the topographical chart.

A fishfinder in which signal transmission is conducted between a reception antenna formed on a display rotation plate and a transmission antenna formed on a connection plate, both the reception antenna and the transmission antenna being opposed each other, and electric power transmission is conducted between a pair of inductive coupling coils, one being formed on the display rotation plate and the other being formed on the connection plate so as to oppose each other.

A marine sonar display device comprises a display, a memory element, and a processing element. The display displays sonar images. The memory element stores sonar data. The processing element is configured to transmit a transmit electronic signal to a frequency steered sonar element which transmits an array of sonar beams into a body of water, each sonar beam transmitted in a different angular direction, receive a receive electronic signal from the frequency steered sonar element, the receive electronic signal including a plurality of frequency components, calculate an array of sonar data slices, one sonar data slice for each frequency component, generate an array of sonar image slices, one sonar image slice for each sonar data slice, and control the display to visually present the array of sonar image slices in near real time and a historical sequence of at least one sonar image slice.

A marine sonar display device comprises a display, a memory element, and a processing element. The display displays sonar images. The memory element stores sonar data. The processing element is configured to transmit a transmit electronic signal to a frequency steered sonar element which transmits an array of sonar beams into a body of water, each sonar beam transmitted in a different angular direction, receive a receive electronic signal from the frequency steered sonar element, the receive electronic signal including a plurality of frequency components, calculate an array of sonar data slices, one sonar data slice for each frequency component, generate an array of sonar image slices, one sonar image slice for each sonar data slice, and control the display to visually present the array of sonar image slices in near real time and a historical sequence of at least one sonar image slice.

An environment measurement system according to the present invention is provided with a first unit comprising: a transmitter which is located undersea and transmits an acoustic wave in a designated direction a plurality of times; a first receiver which is located undersea and receives an acoustic wave reflected by a reflecting body at the sea surface or the seabed; a transmission direction setting unit which designates, to the transmitter, transmission directions specified in advance by a user, so as to cause the transmitter to transmit acoustic waves in the directions; a first necessary time measurement unit which, for each of the transmission directions, measures from the transmission and reception times of an acoustic wave a time necessary for the acoustic wave to return, as a necessary time, and outputs an average of the measured necessary time as an average necessary time for each of the transmission directions; a layer setting unit which partitions between the sea surface and the seabed into layers each extending horizontally, at intervals of preset distances; a simultaneous equations set-up unit which sets up simultaneous equations using the transmission directions, the necessary times and the layer thicknesses and taking average sound velocities in the respective layers as unknown variables; a simultaneous equations solving unit which solves the simultaneous equations; an initial parameter setting unit which sets initial values necessary for the simultaneous equations solving unit to solve the simultaneous equations, as parameter initial values; and a sound velocity profile output unit which creates a profile of sound velocities obtained by determining solutions acquired by the simultaneous equations solving unit to be average sound velocities in the respective layers and arranging the average sound velocities in the respective layers in order of depth, and outputs the profile.