JP7447513B2 - Sonar device and target direction calculation method and program - Google Patents

Description

The present invention relates to a sonar device, a target direction calculation method, and a program.

In recent years, the use of unmanned aerial vehicles in the ocean has expanded. Sensors mounted on unmanned aircraft need to be smaller than those on manned boats. However, although these sensors are small, they are required to search at long distances and with high resolution equivalent to those of large sensors.

Patent Document 1 discloses a technique related to the split beam method in which the outputs of a plurality of receivers are phased to form and receive a plurality of split beams having equal left and right receiving beams in any direction. A technique has been disclosed for obtaining a sonar image with high lateral resolution by using split beam processing in which the center distance between left and right receiving beams is wide. However, a virtual image is generated due to phase inversion caused by split beam processing. This phase inversion problem will be outlined below based on the description in Patent Document 2 and the like.

・・・(1)
より、

・・・(2)
で与えられる。ただし、sin^-1は逆正弦関数（arcsine）である。 In the conceptual diagram shown in FIG. 11, a plurality of left and right split beams are formed at equal azimuth intervals using the outputs of a plurality of receivers of left and right subarrays. The beam centers of the left and right split beams are separated by a distance d. If the direction in which the signal from the target arrives is θ, then d·sin θ is the difference (difference) between the target distances of the left and right beams. If the phase difference between the received signal obtained with the left split beam and the received signal obtained with the right split beam (interbeam phase difference) is Δφ, the frequency of the transmitted signal is f, and the speed of sound is c, one wavelength λ (=c /f) has a phase of 2π, so

...(1)
Than,

...(2)
is given by However, sin ^-1 is an arcsine function.

・・・(3)
である。 In this case, it is not possible to distinguish between Δφ=φ ₀ (|φ ₀ |<π) and Δφ=φ ₀ ±2nπ (n=1, 2,...) due to the periodicity of the phase (this is called phase inversion or phase folding). . Since the possible range of the phase difference Δφ is within ±π, the true target direction is

...(3)
It is.

・・・(4) A signal arriving from outside the true target azimuth range shown by the above equation (3) is determined to be from an azimuth (true target azimuth) within the range of the above equation (3) by calculating the above equation (2). False detection occurs. Therefore, a signal with a good S/N (Signal to Noise) value is input in addition to the beam channel of the assigned direction corresponding to the target direction, and the signal is displayed on the display as shown in the following equation (4). Directions outside the true target direction range may be displayed as imaginary targets.

···(Four)

As a method for preventing false detection due to such phase inversion, for example, the angular width of the azimuth range is expanded by narrowing the beam center distance (beam center spacing). For example, in Patent Document 2, as an active sonar device that suppresses the generation of virtual images, in addition to a plurality of first split beams formed to display received signals, means for forming a plurality of narrow second split beams and the presence or absence of spread between beam channels of the signal amplitude obtained from the first split beam output calculated from the first and second split beams; The apparatus includes an azimuth angle selection means for selecting one of the azimuth angle values, and a display control means for controlling the display of the signal received by the first split beam according to the azimuth angle value. In Patent Document 2, split beams having a narrow center spacing between left and right reception beams but wide directivity are combined.

In Patent Document 3, the azimuth angle detection device first generates split beam data for each left and right beam from received data, takes the vector sum of the left and right beams to generate a full beam, performs Fourier transform, and converts the data to the background level. On the other hand, the azimuth angle detection section detects a frequency at a prominent level, calculates the phase difference between the left and right beams at the frequency, and uses the phase difference φ received from the phase difference detection section and the signal frequency f received from the frequency detection section as keys. An azimuth angle detection device is disclosed that refers to a phase difference table, determines a signal arrival azimuth, and outputs it as azimuth data. The phase difference table is a table in which the frequency, phase difference, and signal arrival direction are paired by calculating the azimuth angle for an arbitrary arrival direction signal using the inter-beam distance d in advance. .

Japanese Unexamined Patent Publication No. 59-72073 Japanese Patent Application Publication No. 2000-147096 Japanese Patent Application Publication No. 2008-8643

The analysis results of related technologies are shown below. In Patent Document 2, reception is performed using a beam with a low directional gain (ratio of the power density in a specific direction to the average value of the total radiated power in all directions), so the S/N (Signal to Noise) is low. cannot receive signals.

In Patent Document 3, the direction is calculated using a pair of left and right split beams. Since a full beam is generated by taking the vector sum of the left and right beams, it is a split beam with no overlap.

An object of the present invention is to provide a sonar device that can display, for example, an image with a desired resolution while suppressing virtual images in sonar display.

According to one aspect of the present invention, the acoustic array includes a predetermined number of channels of three or more, and the first beam is formed using all the channels in a predetermined area of the acoustic array. , a plurality of azimuth information for one target is obtained from received signals obtained by beams of at least three subarrays that partially overlap with one other subarray using some channels in the predetermined area of the acoustic array. A sonar device is provided, which includes a reception processing unit that calculates.

According to one embodiment of the present invention, when calculating a target direction of a sonar device having an acoustic array configured with a predetermined number of channels of three or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. A target azimuth calculation method is provided that calculates a plurality of azimuth information for one target from received signals obtained from beams of subarrays.

According to one aspect of the present invention, a computer that configures a sonar device having an acoustic array configured with a predetermined number of channels of three or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. A program is provided that executes a process of calculating a plurality of pieces of azimuth information for one target from received signals obtained from beams of subarrays.

Furthermore, according to the present invention, a semiconductor storage such as a computer readable recording medium (for example, RAM (Random Access Memory), ROM (Read Only Memory), or EEPROM (Electrically Erasable and Programmable ROM)) storing the above program; , HDD (Hard Disk Drive), CD (Compact Disc), and DVD (Digital Versatile Disc)).

According to the present invention, it is possible to obtain an image display with a desired resolution while suppressing virtual images in sonar display.

1 is a diagram illustrating a configuration of an embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration of a reception processing section according to an embodiment of the present invention. (A) to (D) are diagrams illustrating examples of channels used in four types of beams: a full beam, a direction detection beam, a left split beam, and a right split beam in an embodiment of the present invention. FIG. 2 is an explanatory diagram showing an outline of a beam in an embodiment of the present invention. (A) and (B) are diagrams illustrating the relationship between the inter-beam phase difference and the output azimuth in an embodiment of the present invention. FIG. 3 is a diagram schematically illustrating an example of a display result (two-dimensional brightness plot) in an embodiment of the present invention. (A) to (D) are diagrams illustrating an example of a channel used in a modification of an embodiment of the present invention. It is a figure which illustrates the structure of the reception processing part in another embodiment of this invention. (A) to (G) are diagrams illustrating an example of a channel used in a modification of an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of implementation of a computer device. It is a conceptual diagram explaining phase inversion in a split beam.

In the sonar device of the present invention, an acoustic array (reception a first beam formed using all the channels in the predetermined region of the acoustic array; and at least three sub-array beams using some channels in the predetermined region of the acoustic array. A plurality of pieces of azimuth information are calculated for one target from the received signal obtained by In the at least three subarrays, at least two subarrays (eg, FIGS. 3(C) and 3(D)) partially overlap with at least one other subarray (eg, FIG. 3(B)). According to one aspect of the present invention, as the first beam, a full beam (301 in FIG. 4) that utilizes all channels in a predetermined area (the entire area or a part) of the acoustic array is generated, and the full beam is generated. The direction detection beam (302 in Figure 4) is created by a sub-array that shares a part of the channel of the acoustic array and does not undergo phase inversion with the full beam, and the first and second split beams (302 in Figure 4) are created by a sub-array that separates the channel of the acoustic array. 303, 304), detects a first orientation based on the full beam and the orientation detection beam, detects a second orientation based on the first and second split beams, and detects the orientation corresponding to the first orientation. Target azimuth information is acquired based on phase difference information between the full beam and the azimuth detection beam and phase difference information between the first and second split beams corresponding to the second azimuth. With this configuration, it is possible to obtain an image display with desired resolution and processing gain while suppressing virtual images due to phase inversion.

FIG. 1 is a diagram schematically showing a configuration example (system configuration example) of an active sonar device as a sonar device according to an embodiment of the present invention. In sonar device 10, acoustic array 11 consists of an array of acoustic elements that perform electro-acoustic conversion of transmitted and received signals. The receiving section (receiving device) 12 includes an analog-to-digital converter (not shown) that performs analog-to-digital conversion on the received signal of each channel of the acoustic array 11. The reception processing section (reception processing device) 13 performs sonar signal processing on the reception signal digitized by the reception section (reception device) 12. The transmitter (transmitter) 14 generates a transmission signal to be transmitted from each channel of the acoustic array 11 and supplies it to the channels of the acoustic array 11. The transmitter (transmitter) 14 may include a digital-to-analog converter that converts a digital transmission signal into an analog signal. The display unit (display device) 15 displays the processing results output from the reception processing unit (reception processing device) 13.

FIG. 2 is a diagram schematically showing the processing performed by the reception processing section 13 of FIG. 1. In FIG. 2, received data 201 is a received signal (digital signal) of each of the first to Nth channels. The replica correlation processing unit 202 is disposed corresponding to each channel, and performs cross-correlation between the received signal of each channel and the replica signal (digital signal) of the transmitted signal, and calculates a gain for the received signal of each channel. obtain.

The replica correlation processing section 202 performs directional synthesis processing on the received signals for each channel that have obtained gains. Directivity synthesis processing obtains directivity by delaying and aligning the phases of the received signals in each channel of the acoustic array 11 and adding them together to emphasize the signal in the target direction. The directional synthesis processing units 203 to 206 perform a full beam, a direction detection beam, a left split beam (split beam L), and a right split beam (split beam R) for the received signals of the channels in each receiver of the acoustic array 11, respectively. ) generates four types of beams.

The level calculation processing unit 207 receives the full beam output from the directional synthesis processing unit 203 (full beam) and calculates the level from the full beam.

A direction detection processing section (direction detection beam) 208 performs direction detection processing from the full beam output from the directional synthesis processing section 203 and the direction detection beam output from the directional synthesis processing section 204.

A direction detection processing section (split beam) 209 performs direction detection processing from the left split beam outputted from the directional synthesis processing section 205 and the right split beam outputted from the directional synthesis processing section 206. Based on the processing results of the level calculation processing section 207, direction detection processing section 208, and direction detection processing section 209, a brightness generation processing section 210 generates a signal for the display device.

FIGS. 3A to 3D show a full beam, a direction detection beam, and a left split beam generated by the directional synthesis processing units 203 to 206 in an acoustic array 11 consisting of 32 acoustic elements (4 vertically x 8 horizontally). An example of channels used for four types of beams: (split beam L) and right split beam (split beam R) is illustrated. Although FIG. 3 schematically shows the acoustic array 11 consisting of 32 acoustic elements (4×8=32 elements) simply for convenience of drawing, the acoustic array 11 is not limited to this number of channels. Of course, there are no limitations. Acoustic array 11 may be configured with any number of channels, from, for example, on the order of three to several thousand. In an acoustic array consisting of 4 vertical by 8 horizontal acoustic elements, hatched squares represent selected channels, and white squares represent unselected acoustic elements (channels). Note that for non-selected channels, the shading coefficient multiplied by the output of the channel may be set to 0. The full beam in FIG. 3A is formed using all channels of the acoustic array 11. In FIG. 3B, one row of acoustic elements at the left end is unselected, and the subarray is composed of 4 vertical by 7 horizontal acoustic elements. 3(C) is a left half subarray of 4 vertical by 4 horizontal acoustic elements, and FIG. 3(D) is a right half of a subarray of 4 vertical by 4 horizontal acoustic elements. The subarray in FIG. 3(B) overlaps a part of FIG. 3(A), the subarray in FIG. 3(C) has some channels overlapped with the subarray in FIG. 3(B), and the subarray in FIG. 3(D) overlaps with the subarray in FIG. The subarray overlaps a portion of the subarray in FIG. 3(B). The subarray in FIG. 3(B) and the subarray in FIG. 3(C), and the subarray in FIG. 3(B) and the subarray in FIG. 3(D) are respectively configured to partially overlap, and the full beam in FIG. The distance between the beam centers of the direction detection beams in FIG. 3(B) is set smaller than the distance between the beam centers of the left and right split beams in FIGS. 3(C) and (D), and the direction detection beam is different from the full beam. The angular width of the azimuth range between the beam and the full beam is expanded, and no virtual image is generated due to phase reversal between the beam and the full beam.

FIG. 4 is a diagram showing an overview of beams generated by the directional synthesis processing units 203 to 206 in FIG. 2. FIG. 4 schematically shows an example in which the beam is shifted in the direction of θ with respect to the front of the array (normal direction). The distance between the beam center of the full beam 301 and the beam center of the direction detection beam 302 (beam center spacing) is R _DB , and the distance between the beam center of the left split beam 303 and the beam center of the right split beam 304 (beam center spacing) becomes R _SB (R _SB > R _DB ). In the case of the channel configuration in FIG. 3, R _DB in FIG. 4 is between the beam center of the full beam 301 (between the fourth acoustic element and the fifth acoustic element from the left in FIG. It can be made to correspond to the distance between the beam centers (the center of the fifth acoustic element from the left in FIG. 3(B)). _RSB in FIG. 4 can correspond to the lateral distance of four acoustic elements between the beam center of the left split beam and the beam center of the right split beam.

・・・(5)
が示されている。横軸は、

・・・(6)

であるが、図５（Ａ）では、容易化のため、位相差Δφ(radian）で表している。また、逆正弦関数（sin^-1）を直線で示（近似）している。 FIG. 5(A) is a diagram showing the relationship between the inter-beam phase difference Δφ (horizontal axis) input to the azimuth detection processing unit 208 that inputs the full beam and the azimuth detection beam and the output azimuth (θ) (vertical axis). , arcsine function where d in the above formula (2) is R _DB

···(Five)
It is shown. The horizontal axis is

...(6)

However, in FIG. 5A, for the sake of simplicity, the phase difference is expressed as Δφ (radian). Also, the arc sine function (sin ^-1 ) is shown (approximated) by a straight line.

・・・(7)

が示されている。
横軸は、

・・・(8)

であるが、図５（Ｂ）では、容易化のため、位相差Δφ(radian)で表している。また、逆正弦関数（sin^-1）を直線で示している。 FIG. 5(B) is a diagram showing the relationship between the inter-beam phase difference (Δφ) input to the azimuth detection processing unit 209 which inputs the left split beam and the right split beam and the output azimuth (θ). Arc sine function where d in 2) is _RSB

...(7)

It is shown.
The horizontal axis is

...(8)

However, in FIG. 5B, the phase difference is expressed in Δφ (radian) for simplicity. Also, the arc sine function (sin ^-1 ) is shown as a straight line.

・・・(9)
当該方位を真の目標方位４０１とする（なお、式（９）において＝は≒であってもよい）。本実施形態によれば、図５（Ｂ）において、例えば真の目標方位範囲外の位相差Δφ＝α±２πの信号を位相反転により位相差Δφ＝αに対応する方位（真の目標方位範囲内の方位）として誤検出しても、図５（Ａ）において、位相差Δφ＝α’には方位が検出されないため、図５（Ｂ）で誤検出された当該方位は表示しない。このため、ソーナー表示において、左右スプリットビームでの位相反転による虚像を抑制しながら、所望の精度（分解能）で画像表示することができる。 As shown in FIG. 5A, the azimuth calculated from the full beam and the azimuth detection beam has low accuracy (resolution) of the output azimuth, but the angle of the true target azimuth range is large, and no virtual image is generated. As shown in FIG. 5B, the azimuth θ calculated from the left split beam and the right split beam has high accuracy (resolution) of the output azimuth, but a virtual image is generated. In FIG. 5(B), the true target azimuth range is α±π with respect to the inter-beam phase difference Δφ=α between the left split beam and the right split beam, but the phase difference outside the true target azimuth range is α± n×2π is also erroneously detected as the true target orientation. Here, the true target orientation 401 is a location where the two types of output orientations have the same value. In other words, the value of equation (6) regarding the inter-beam phase difference (horizontal axis) corresponding to the direction detected in FIG. 5(A) and the inter-beam phase difference (horizontal axis) corresponding to the direction detected in FIG. 5(B) When the values of equation (8) regarding the horizontal axis (horizontal axis) match (inter-beam phase difference Δφ=α′ in FIG. 5(A), inter-beam phase difference Δφ=α in FIG. 5(B)),

...(9)
The azimuth is set as the true target azimuth 401 (= may be ≈ in equation (9)). According to this embodiment, in FIG. 5(B), for example, a signal with a phase difference Δφ=α±2π outside the true target azimuth range is phase-inverted so that the azimuth corresponding to the phase difference Δφ=α (true target azimuth range Even if the orientation is erroneously detected as an azimuth within the azimuth range, the azimuth that is erroneously detected in FIG. 5(B) is not displayed because no azimuth is detected at the phase difference Δφ=α′ in FIG. 5(A). Therefore, in sonar display, images can be displayed with desired accuracy (resolution) while suppressing virtual images due to phase inversion between the left and right split beams.

FIG. 6 is a diagram showing a two-dimensional brightness plot for sonar information display generated by the brightness generation processing unit 210. The horizontal axis is the direction (target direction), and the vertical axis is the distance d. The distance is calculated from the transmission-reception time difference between the transmitted signal and the received signal. The azimuth resolution on the display is determined by the interval at which receiving beams are generated, and target information is plotted at the azimuth only when the azimuth is determined to be the true azimuth by the azimuth detection processing of the two methods. The brightness value is an output value from the level calculation processing unit 207 using a full beam. In the two-dimensional brightness plot of FIG. 6, each grid determined by the target direction and distance is shown filled in (gradation) with a gradation that is the brightness of the screen actually displayed on the display unit 15. That is, the higher the luminance (brighter), the darker it is in the diagram. A white (empty) grid corresponds to no target being detected at that orientation and distance.

According to one embodiment, by generating receive beams at intervals narrower than the beam width (the angular width of the range (half width) in which the sound pressure decreases by 1/√2 around the principal axis), a high It is possible to display sonar information with resolution. Furthermore, by performing a plurality of orientation detection processes, it is possible to suppress the generation of virtual images.

According to one embodiment, by calculating multiple azimuth information by simultaneously processing a sub-array (acoustic sub-array) with a wide beam center spacing and a sub-array with a narrow beam center spacing, virtual images generated in split beam processing are suppressed. Direction detection becomes possible.

Further, according to one embodiment, by overlapping the channels of the beams used in the subarray for direction detection, the direction can be detected with a beam having a high directivity gain. Therefore, the direction of a long-distance target can also be detected.

In the embodiment described above, a two-dimensional planar array was illustrated as the acoustic array 11, but it goes without saying that the configuration is not limited to this. 7A to 7D show the generation of a full beam, a direction detection beam, a left split beam (split beam L), and a right split beam (split beam R) when a cylindrical array is used as the acoustic array 11. An example of channel division is shown in a top view (a semicircle that is part of the circumference) of the cylindrical array. In the example of FIG. 7A, a full beam is formed from a predetermined area (nine consecutive hatched channels, excluding two at both left and right ends) of a part (semicircle) of the cylindrical array. In the example of FIG. 7(B), out of the nine acoustic elements used to form the full beam of FIG. 7(A), the direction detection beam is is generated. In the examples shown in FIGS. 7(C) and (D), the left split beam is generated from four consecutive acoustic elements on the left and right sides of the nine consecutive channels used to form the full beam in FIG. 7(A). , a right split beam is generated.

In addition, there are multiple channels such as line arrays in which acoustic elements are arranged in a straight line, annular arrays in which acoustic elements are arranged along a circular ring, and conformal arrays in which acoustic elements are arranged along a curved surface. It is applicable to sonar devices that have

Further, in one embodiment, an active sonar device has been described as an example, but the present invention is also applicable to a passive sonar device.

FIG. 8 is a diagram illustrating a configuration of a reception processing section in an embodiment of passive processing. A passive sonar device receives sound waves emitted from a sound source in a remote location such as a ship, and analyzes the signals to determine the presence and direction of the sound source. An acoustic array (receiver array) is placed, the reception directionality is given in a specific direction by phasing processing, the characteristic frequency is extracted by frequency analysis for the reception signal, and the phase difference or reception The signal arrival direction is calculated from the signal energy distribution. In the example of FIG. 8, an FFT (Fast Fourier Transform) processing section 502 is provided in place of the replica correlation processing section 202 of FIG. N FFT processing units 502 provided corresponding to N channels each cut out received data (digital received data) from the corresponding channel in a predetermined time window, and receive received data for each cut out time section. Derive the frequency spectrum by fast Fourier transform. The directivity synthesis processing units 503 to 506 perform phase adjustment (delay compensation and azimuth setting) for each frequency component (frequency bin) of the frequency spectrum from the FFT processing unit 502 of each channel. Generates a full beam, orientation detection beam, left split beam, and right split beam in the area. Level calculation processing section 507, direction detection processing sections 508 and 509, and brightness generation processing section 510 perform level calculation, direction detection, and brightness generation based on the outputs (frequency spectrum information) from directivity synthesis processing sections 503 to 506, respectively. Processing may also be performed.

In the embodiment described above, two-dimensional information was obtained, but it is also applicable to three-dimensional information. FIG. 9 shows an example of channel division when obtaining three-dimensional information. In addition to the full beam, direction detection beam, left split beam (split beam L), and right split beam (split beam R) shown in Figure 3, the direction detection beam (vertical), up split beam (split beam U), and down split beam (split beam Beam D) is added, and two horizontal orientations and two vertical orientations can be obtained for the beam shifted in one orientation. 9(A), (E), (F), and (G) are the same as FIG. 3(A), (B), (C), and (D). In FIG. 9B, the acoustic elements in the bottom row are not selected, and the subarray is composed of a 3×8 acoustic element subarray. FIG. 9(C) shows a subarray of 2×8 acoustic elements in the upper half, and FIG. 9(D) shows a subarray of 4×8 acoustic elements in the lower half. In addition to the directivity synthesis processing units 203 to 206 shown in FIG. 2, the reception processing unit 13 uses the direction detection beam (vertical) shown in FIG. 9(B), the split beam U shown in FIG. 9(C), and the direction detection beam (vertical) shown in FIG. It includes three directional synthesis processing units (not shown) that respectively generate the split beams D shown in FIG. 9(D). In addition to the azimuth detection processing units 208 and 209 shown in FIG. It is equipped with an orientation detection section that detects the orientation in the vertical direction. The subarray in FIG. 9(E) overlaps with a part of FIG. 9(A), the subarray in FIG. 9(F) has some channels overlapped with the subarray in FIG. 9(E), and the subarray in FIG. 9(G) overlaps with the subarray in FIG. The subarray overlaps a portion of the subarray in FIG. 9(E).

In the example shown in FIG. 3, the beam center position of the subarray is changed by changing the channels used in the acoustic array 11, but the beam center position is changed by using all channels and weighting the shading values. You can do it like this.

Figure 5 shows an example of beamforming as delay-sum beamforming, but it is a type of linear filter that uses MVDR (Minimum Variance Distortionless Response), which can emphasize the target audio direction without distortion. Adaptive beamforming including beamformers can also be applied.

FIG. 10 is a diagram illustrating an example in which at least the reception processing section 13 of FIG. 1 is implemented in a computer device 600. Referring to FIG. 10, the computer device 600 includes a processor 601, a semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), etc. (or an HDD (Hard Drive)). A display device 603, and an interface 604 (network interface, bus interface) connected to the transmitter 14 and receiver 12 in FIG. 1 are provided. The processor 601 may be a DSP (Digital Signal Processor). By reading and executing the program 605 stored in the memory 602, the processor 601 executes the processing of the reception processing unit 13 in FIG. Note that the processor 601 may execute part of the processing of the transmitter 14 in FIG. 1. The display device 603 corresponds to the display section (display device) 15 in FIG.

In the above embodiment, an application example was explained for underwater acoustics, but the same sensor device and signal processing method can also be applied to cases where acoustics are used in the air, or cases where electromagnetic waves such as radar are used instead of sound waves. Applicable.

In addition, each disclosure of the above-mentioned Patent Documents 1, 2, and 3 is incorporated into this document by reference. Within the scope of the entire disclosure of the present invention (including the claims), changes and adjustments to the embodiments and examples are possible based on the basic technical idea thereof. Further, various combinations and selections of various disclosed elements (including each element of each claim, each element of each embodiment, each element of each drawing, etc.) are possible within the scope of the claims of the present invention. . That is, it goes without saying that the present invention includes the entire disclosure including the claims and various modifications and modifications that a person skilled in the art would be able to make in accordance with the technical idea.

10 Sonar device 11 Acoustic array 12 Receiving unit (receiving device)
13 Reception processing unit (reception processing device)
14 Transmission unit (transmission device)
15 Display section (display device)
201, 501 Received data 202 Replica correlation processing section 203-206, 503-506 Directivity synthesis processing section 207, 507 Level calculation processing section 208, 508 Direction detection processing section (direction detection beam)
209, 509 Direction detection processing unit (split beam)
210, 510 Brightness generation processing section 301 Full beam 302 Direction detection beam 303 Left split beam 304 Right split beam 401 True target direction 502 FFT processing section 600 Computer device 601 Processor 602 Memory 603 Display device 604 Interface 605 Program

Claims (8)

It has an acoustic array composed of a predetermined number of channels of 3 or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. Equipped with a reception processing unit that calculates multiple pieces of azimuth information for one target from the received signals obtained from the subarray beams,
In the reception processing section,
generating a full beam as the first beam using all channels in the predetermined area of the acoustic array;
a beam center distance between the full beam and the full beam is set to a first value at which no phase inversion occurs between the beam and the full beam, and a direction detection beam by a first sub-array that utilizes some channels of the acoustic array;
generating first and second split beams by second and third subarrays having a beam center spacing larger than the first value and separating channels in the predetermined region of the acoustic array;
A sonar device characterized in that a target orientation is calculated based on phase difference information between the full beam and the orientation detection beam and phase difference information between the first and second split beams . It has an acoustic array composed of a predetermined number of channels of 3 or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. Equipped with a reception processing unit that calculates multiple pieces of azimuth information for one target from the received signals obtained from the subarray beams,
In the reception processing section,
means for forming a second beam by a first sub-array using some channels of the acoustic array;
The first beam and the second beam are set at a beam center spacing that does not cause phase reversal with respect to a predetermined direction;
means for forming third and fourth beams by second and third subarrays that separate channels in the predetermined region of the acoustic array;
a first orientation detection means for detecting a first orientation related to the predetermined orientation based on the first beam and the second beam;
a second orientation detection means for detecting a second orientation related to the predetermined orientation based on the third beam and the fourth beam;
Furthermore,
Based on the phase difference information between the first and second beams corresponding to the first direction and the phase difference information between the third and fourth beams corresponding to the second direction, A sonar device characterized by calculating a target direction with respect to a direction of. comprising means for forming a fifth beam by a fourth sub-array using some channels of the acoustic array;
The first beam and the fifth beam are set at a beam center spacing that does not cause phase reversal in a direction other than the predetermined direction,
means for forming sixth and seventh beams by fifth and sixth subarrays that separate channels in the predetermined region of the acoustic array;
a third orientation detection unit that detects a third orientation other than the predetermined orientation based on the first beam and the fifth beam;
a fourth orientation detection unit that detects a fourth orientation other than the predetermined orientation based on the sixth beam and the seventh beam;
Equipped with
Based on the phase difference information between the first and fifth beams corresponding to the third direction and the phase difference information between the sixth and seventh beams corresponding to the fourth direction, 3. The sonar device according to claim 2 , wherein the target azimuth is calculated in a azimuth different from the azimuth. The sonar device according to any one of claims 1 to 3 , further comprising a display unit that displays brightness value information regarding the target direction and distance grid. When calculating the target direction with a sonar device having an acoustic array consisting of a predetermined number of channels of 3 or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. Calculates multiple pieces of azimuth information for a single target from the received signals obtained from the subarray beams,
generating a full beam as the first beam using all channels in the predetermined area of the acoustic array;
a beam center distance between the full beam and the full beam is set to a first value at which no phase inversion occurs between the beam and the full beam, and a direction detection beam by a first sub-array that utilizes some channels of the acoustic array;
generating first and second split beams by second and third subarrays having a beam center spacing larger than the first value and separating channels in the predetermined region of the acoustic array;
A target orientation calculation method , comprising: calculating a target orientation based on phase difference information between the full beam and the orientation detection beam, and phase difference information between the first and second split beams . When calculating the target direction with a sonar device having an acoustic array consisting of a predetermined number of channels of 3 or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. Calculates multiple pieces of azimuth information for a single target from the received signals obtained from the subarray beams,
forming a second beam by a first sub-array using some channels of the acoustic array;
The first beam and the second beam are set at a beam center spacing that does not cause phase reversal with respect to a predetermined direction;
forming third and fourth beams by second and third subarrays that separate channels in the predetermined region of the acoustic array;
detecting a first orientation regarding the predetermined orientation based on the first beam and the second beam;
detecting a second orientation related to the predetermined orientation based on the third beam and the fourth beam;
Based on the phase difference information between the first and second beams corresponding to the first direction and the phase difference information between the third and fourth beams corresponding to the second direction, A method for calculating a target direction, characterized in that the target direction is calculated in relation to the direction of the target direction. A computer that configures a sonar device having an acoustic array configured with a predetermined number of channels of three or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams partially overlapping with another subarray using some channels in the predetermined area of the acoustic array. A process of calculating multiple pieces of azimuth information for one target from received signals obtained from beams of subarrays,
generating a full beam as the first beam using all channels in the predetermined area of the acoustic array;
a beam center distance between the full beam and the full beam is set to a first value at which no phase inversion occurs between the beam and the full beam, and a direction detection beam by a first sub-array that utilizes some channels of the acoustic array;
generating first and second split beams by second and third subarrays having a beam center spacing larger than the first value and separating channels in the predetermined region of the acoustic array;
A program that executes processing for calculating a target orientation based on phase difference information between the full beam and the orientation detection beam and phase difference information between the first and second split beams . A computer that configures a sonar device having an acoustic array configured with a predetermined number of channels of three or more,
a first beam formed using all the channels in the predetermined area of the acoustic array; and at least three beams that partially overlap with another subarray using some channels in the predetermined area of the acoustic array. A process of calculating multiple pieces of azimuth information for one target from received signals obtained from beams of subarrays,
forming a second beam by a first sub-array using some channels of the acoustic array;
The first beam and the second beam are set at a beam center spacing that does not cause phase reversal with respect to a predetermined direction;
forming third and fourth beams by second and third subarrays that separate channels in the predetermined region of the acoustic array;
detecting a first orientation regarding the predetermined orientation based on the first beam and the second beam;
detecting a second orientation related to the predetermined orientation based on the third beam and the fourth beam;
Based on the phase difference information between the first and second beams corresponding to the first direction and the phase difference information between the third and fourth beams corresponding to the second direction, A program that causes the computer to execute a process of calculating a target orientation regarding the orientation.

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