Furuno Electric Company Limited

Minoru Handa

Yasushi Nishimori

Akira Okunishi

Hiroshi Iino

Shiroh Ozasa

Hideharu Morimatsu

Masaru Nishida

Rika Shiraki

Asao Kitabatake

Norio Matsuhiro

Hiromune Matsumoto

Mitsuaki Watanabe

Kazutaka Ishida

Hideki Tanaka

An underwater detection apparatus is provided. The underwater detection apparatus includes a transmitter, a receiver, and a hardware processor. The transmitter transmits a transmission wave. The receiver obtains a receive signal based on a reflection of the transmission wave. The hardware processor is programmed to at least detect an underwater target object based at least in part on the receive signal, estimate a density index value of objects within a given area in a vicinity of the underwater target object, and calculate a size index value of the underwater target object based at least in part on the density index value and a target object signal intensity representing a maximum intensity of the receive signal corresponding to the underwater target object.

Underwater detection apparatus

An ultrasonic apparatus is disclosed that includes a transducer having a plurality of transducer elements, a controller operatively connected to the transducer and driving the transducer elements to produce a first ultrasonic transmitting beam having a first frequency and a second ultrasonic transmitting beam having a second frequency; and a processor operatively connected to said transducer for forming and moving reception beams to receive echo signals and extracting frequency components corresponding to said first ultrasonic transmitting beam and said second ultrasonic transmitting beam.

Ultrasonic transmitting/receiving apparatus and scanning sonar employing same

An ultrasonic transmitter generates a reference signal based on a clock signal of a specific frequency and a control signal made up of binary values 0 and 1 for controlling how the level (High or Low) of a carrier drive signal should change, and generates an analog signal constituting the carrier drive signal by pulse-duration-modulating the reference signal. Produced from the carrier drive signal, a driving pulse signal is shaped into a curved waveform having a gradually rising leading edge and a gradually falling trailing edge as the amplitude of the carrier drive signal is gradually increased and decreased based on the control signal.

Ultrasonic transmitter, ultrasonic transceiver and sonar apparatus

A receiving beam is formed using 60 elements arranged in a 90&#xb0; sector area of a cylindrical receiving array. Receiving beamis formed with elementsdivided into two (front and rear) groups. Specifically, the elementsare divided into rear group 1 (elements) and front group 2 (elements) in the beam direction, and the receiving beam is formed by using sample data obtained from the transducer elementsof group 1 in a current scanning cycle as well as sample data obtained from the transducer elementsof group 2 in a preceding scanning cycle. This approach makes it possible to form the receiving beam such that incoming waves of a short-pulse signal would simultaneously hit the relevant transducer elements of the receiving array and thereby improve directivity and sensitivity of the receiving beam for the reception of short-pulse waves.

Method and apparatus for forming a reception beam

A received beam-forming apparatus is disclosed is which echo signals received by multiple ultrasonic transducer elements arranged in a linear form are sampled at a specific scanning frequency to obtain sample data. A receiving beam-forming apparatus includes a memory which stores the sample data derived from multiple scanning cycles; and a beamformer which divides the multiple ultrasonic transducer elements into multiple blocks, reads out the sample data derived from different scanning cycles for the individual blocks from said memory, and forms a receiving beam in a specific direction using the individual sample data which have been read out. A sonar system using the receiving-beam forming apparatus is also disclosed as is a matched filter which selects an arc-shaped part of an ultrasonic transducer element array.

Matched filter, receiving beam-forming apparatus and sonar system

Signals entered from receiving transducer elements of 160 channels are multiplexed into 10 signal lines by 10 multiplexers. Each of 10 A/D converters converts the signals of 16 channels from analog from into digital form. The multiplexers are switched with synchronized switching timing to produce 10 pieces of sample data strings with the same timing. 160 pieces of sample data sampled in a steplike form are shifted in phase according to an oblique-line sampling scheme. The signal of the same channel is sampled twice with a phase delay of 90&deg; so that the signal can be converted into complex-valued sample data without increasing the number of processing circuits.

Signal processing method and apparatus, and sonar systems

Position detecting device for use with omega navigating apparatus which includes a receiver for receiving two omega signals from different stations, a synchronous generator for producing first and second signals synchronized with the omega signals and frequency dividing the synchronized signals by a common divisor to produce first and second frequency-divided waves, frequency dividing means for dividing the phase difference between the frequency-divided waves by the period of the omega signals to produce an integral quotient which constitutes a lane number while the remainder represents the phase difference between the first and second omega signals.

Growing community of inventors

Nishinomiya, Japan

Minoru Handa