Underwater detection device

An underwater detection device, comprising:

• a transceiver module for transmitting underwater an ultrasonic pulse signal that is frequency-modulated and receiving an echo signal corresponding to the transmitted signal;
• a pulse compression module for pulse-compressing the signal received by the transceiver module and outputting a signal pulse-compressed;
• a suppression range determining module for determining a suppression range where a range side lobe suppression process is performed for the pulse-compressed signal;
• an echo determining module for determining whether the data of the pulse-compressed signal at each depth corresponding to a range side lobe;
• a suppression value determining module for determining a suppression value for the data of the pulse-compressed signal at each depth;
• a suppression conducting module for performing a calculation to suppress the range side lobe based on the suppression value for the data determined to be data of the pulse-compressed signal corresponding to the range side lobe by the echo determining module among a plurality of data of the pulse-compressed signals that fall into the suppression range;
• and
• a display processing module for generating a signal for display based on the signal outputted from the suppression conducting module to display a generated signal as detected information.

An underwater detection device, comprising:

• a transceiver module for transmitting underwater an ultrasonic pulse signal that is frequency-modulated and receiving an echo signal corresponding to the transmitted signal;
• a pulse compression module for pulse-compressing the signal received by the transceiver module and outputting a signal pulse-compressed;
• a suppression range determining module for determining a suppression range where a range side lobe suppression process is performed for the pulse-compressed signal, the suppression range determining module including
• a forward peak-hold module that selects, for each depth, data with the largest signal strength among data of the pulse-compressed signals falling into a depth range from the depth concerned to a depth deeper by a predetermined depth, and outputs the selected data as a forward peak-hold value of the depth concerned
• an echo determining module for determining whether the data of the pulse-compressed signal at each depth corresponding to a range side lobe;
• a suppression value determining module for determining a suppression value for the data of the pulse-compressed signal at each depth;
• a suppression conducting module for performing a calculation to suppress the range side lobe based on the suppression value for the data determined to be data of the pulse-compressed signal corresponding to the range side lobe by the echo determining module among a plurality of data of the pulse-compressed signals that fall into the suppression range;
• and
• a display processing module for generating a signal for display based on the signal outputted from the suppression conducting module to display a generated signal as detected information,
• wherein when a value obtained by dividing the forward peak-hold value by the data of the pulse-compressed signal at the same depth is greater than a second predetermined threshold, the echo determining module determines the data concerned to be data corresponding to a range side lobe.