Abstract: A processor of a sonar system extracts a signal in a predetermined time range from a signal received by an acoustic array, calculates a correlation value for a signal waveform extracted, detects a peak value of the correlation value, calculates an integrated value by performing time-integration of a square of the correlation value, obtains a target velocity based on the peak value and the integrated value, and displays the target velocity on a display apparatus.

Abstract: A system including a transmitter and a receiver array at a location different from that of a transmitter, virtually divides the receiver array into plural sub-arrays, calculate Doppler coefficients based on movement of a target for the sub-arrays, calculates a velocity vector of a target, by using the Doppler coefficients calculated for the sub-arrays, and display velocity vector of the target.

Abstract: A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

Abstract: A processor of a sonar system extracts a signal in a predetermined time range from a signal received by an acoustic array, calculates a correlation value for a signal waveform extracted, detects a peak value of the correlation value, calculates an integrated value by performing time-integration of a square of the correlation value, obtains a target velocity based on the peak value and the integrated value, and displays the target velocity on a display apparatus.

Abstract: In order to enhance the performance with which a moving target is detected by a single sensor and with a degree of freedom in a transmission waveform, a moving-target detection system 1 has a transmission waveform setting means 101 for setting a transmission waveform St(t), a transmission means 102 for transmitting a wave having the set transmission waveform St(t), a reception means 103 for receiving a wave including a reflected wave from a target, a Doppler shift estimation means 104 for estimating a Doppler shift that occurs due to movement of the target from the transmission waveform St(t) and a reception waveform Sr(t) including the reflected wave, a transmission waveform deformation means 105 for generating a deformed transmission waveform in which the transmission waveform St(t) is deformed in accordance with the estimated Doppler shift, and a target sensing means 106 for sensing the target using the deformed transmission waveform.

Abstract: A moving object detection system comprises: a transmission waveform setting section to set a transmission signal in such a way that a frequency of the transmission signal is linearly changed; a transmitting section to transmit the transmission signal; a receiving section to receive a reception signal resulting from a reflection of the transmission signal at an object; a Doppler coefficient estimating section to estimate a Doppler coefficient associated with a movement of the object by performing arithmetic processing on a waveform of the reception signal at a present time point and waveforms of the reception signal at one or more past time points, the one or more past time points being earlier than the present time point by one or more specified periods of time; and an object detection section to detect the object based on the transmission signal, the Doppler coefficient, and the reception signal.

Abstract: A target search system includes: a signal processing unit that is input with a received signal including a reflected wave based on a pulsed transmission wave modulated in linear frequency modulation, calculates mutual correlation between the transmission wave and the received signal, and amplifies a power ratio of a signal component of a reflected wave from a target and another signal component at a predetermined process gain; a specifying unit by which a user specifies one value of a pulse length, a frequency change ratio, and a frequency amplitude of the transmission wave and the process gain; and a transmission wave determination unit that determines a remaining value of the transmission wave based on the specified one value of the pulse length, the frequency change ratio, and the frequency amplitude of the transmission wave and the specified process gain so as to satisfy a relational equation for the process gain.

Abstract: A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

Abstract: A signal processing device for processing a signal of a reflected wave which is a wave reflected in a medium and is received by a receiver, when a wave propagating through the medium is continuously transmitted by a transmitter. The signal processing device includes: an estimation unit configured to estimate a lower limit distance of a detection distance range for which an intensity level of a scattered wave from the medium in the detection distance range is equal to or smaller than an allowable level; and a scattering reduction unit configured to remove, from a signal of the reflected wave received, a signal of the scattered wave from the medium in a masking region from the receiver to the lower limit distance to perform output.

Abstract: The present invention enables control of the specifications of a transmission unit and reception unit in a manner so as to reduce the effect of scattered waves reaching the reception unit as a result of scattering caused by the medium through which wave propagates. This target detection device has a transmission unit, a reception unit, a detection unit, and a control unit. The control unit controls the specifications of the transmission unit and reception unit in a manner so as to satisfy a relational equation for reducing the effect of scattered waves reaching the reception unit due to scattering caused by the medium through which wave propagates. The transmission unit transmits wave, and the reception unit receives the reflection wave of the wave reflected by a detection subject. The detection unit detects the detection subject on the basis of the output of the reception unit.

Abstract: In order to enhance the performance with which a moving target is detected by a single sensor and with a degree of freedom in a transmission waveform, a moving-target detection system 1 has a transmission waveform setting means 101 for setting a transmission waveform St(t), a transmission means 102 for transmitting a wave having the set transmission waveform St(t), a reception means 103 for receiving a wave including a reflected wave from a target, a Doppler shift estimation means 104 for estimating a Doppler shift that occurs due to movement of the target from the transmission waveform St(t) and a reception waveform Sr(t) including the reflected wave, a transmission waveform deformation means 105 for generating a deformed transmission waveform in which the transmission waveform St(t) is deformed in accordance with the estimated Doppler shift, and a target sensing means 106 for sensing the target using the deformed transmission waveform.

Abstract: A target search system includes: a signal processing unit that is input with a received signal including a reflected wave based on a pulsed transmission wave modulated in linear frequency modulation, calculates mutual correlation between the transmission wave and the received signal, and amplifies a power ratio of a signal component of a reflected wave from a target and another signal component at a predetermined process gain; a specifying unit by which a user specifies one value of a pulse length, a frequency change ratio, and a frequency amplitude of the transmission wave and the process gain; and a transmission wave determination unit that determines a remaining value of the transmission wave based on the specified one value of the pulse length, the frequency change ratio, and the frequency amplitude of the transmission wave and the specified process gain so as to satisfy a relational equation for the process gain.

Abstract: A moving object detection system comprises: a transmission waveform setting section to set a transmission signal in such a way that a frequency of the transmission signal is linearly changed; a transmitting section to transmit the transmission signal; a receiving section to receive a reception signal resulting from a reflection of the transmission signal at an object; a Doppler coefficient estimating section to estimate a Doppler coefficient associated with a movement of the object by performing arithmetic processing on a waveform of the reception signal at a present time point and waveforms of the reception signal at one or more past time points, the one or more past time points being earlier than the present time point by one or more specified periods of time; and an object detection section to detect the object based on the transmission signal, the Doppler coefficient, and the reception signal.

Abstract: A signal processing device for processing a signal of a reflected wave which is a wave reflected in a medium and is received by a receiver, when a wave propagating through the medium is continuously transmitted by a transmitter. The signal processing device includes: an estimation unit configured to estimate a lower limit distance of a detection distance range for which an intensity level of a scattered wave from the medium in the detection distance range is equal to or smaller than an allowable level; and a scattering reduction unit configured to remove, from a signal of the reflected wave received, a signal of the scattered wave from the medium in a masking region from the receiver to the lower limit distance to perform output.

Abstract: 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

Abstract: The present invention enables control of the specifications of a transmission unit and reception unit in a manner so as to reduce the effect of scattered waves reaching the reception unit as a result of scattering caused by the medium through which wave propagates. This target detection device has a transmission unit, a reception unit, a detection unit, and a control unit. The control unit controls the specifications of the transmission unit and reception unit in a manner so as to satisfy a relational equation for reducing the effect of scattered waves reaching the reception unit due to scattering caused by the medium through which wave propagates. The transmission unit transmits wave, and the reception unit receives the reflection wave of the wave reflected by a detection subject. The detection unit detects the detection subject on the basis of the output of the reception unit.

Abstract: A target tracking system which tracks targets using a plurality of virtual particles includes a detector which detects the targets based on a signal wave from the targets and outputs a detected results as a detected target positions, a fluctuation distribution unit which generates fluctuations arising from at least disturbances and measurement errors, and an estimation unit which sets virtual particles based on the fluctuations and estimates a true target positions based on the detected target positions.

Abstract: 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

Abstract: An object detection and tracking support system includes a setting unit, a transmission level obtaining unit, a propagation loss function estimating unit that, based on various information relating to a transmitter and a receiver stored in the setting unit, calculates the propagation loss as a propagation loss function expressed as a function of the distance and the direction viewed from the receiver, a target strength obtaining unit that, in regard to an object of object information stored in the setting unit, extracts a target strength of the object from an external database; and a detection signal level function estimating unit that, based on transmission level information obtained by the transmission level obtaining unit, a propagation loss function calculated by the propagation loss coefficient estimating unit, and a target strength extracted by the target strength obtaining unit, determines a detection signal level function, for display on an external display unit.

Abstract: Provided is a technique capable of suppressing the deterioration in azimuth resolution and distance resolution in even a modulated and transmitted or received signal or a signal reflected by an object and varied in intensity when acquiring waveform information. A measurement device comprise: a plurality of sensors which receive waves propagating through a space; and a sampling timing calculation means which obtains, on the basis of the relative positions of the sensors and the velocities of the waves, the difference between the arrival times of the waves received by the respective sensors and calculates, for each sensor, sampling timing for acquiring the waveform information relating to the waves, on the basis of the difference between the arrival times.