Signal direction display processing device, signal processing system, signal direction display processing method, and program for signal direction display processing method

Abstract

To obtain a signal azimuth indication processing device, etc., with which it is possible to more clearly indicate an arriving horizontal azimuth and an elevation angle of a target and the number of targets.SOLUTION: There is provided a signal azimuth indication processing device 300 that performs a process of indicating a horizontal azimuth and an elevation angle in which a target signal arrives, said device comprising: an ELAZ interpolation processing unit 320 that performs the process of converting a conical coordinate system into two-dimensional conversion data on the basis of a result of horizontal phasing processing of the target signal; a target detection processing unit 330 that generates data pertaining to target signal arrival azimuth information in the conical coordinate system including a signal level at which the target signal is maximized; a coordinate conversion processing unit 340 that converts the target signal arrival azimuth information; and an indication processing unit 350 that generates indication data for plotting the signal level to the corresponding horizontal azimuth and elevation angle positions, on the basis of the arrival azimuth information by a horizontal azimuth-elevation angle coordinate system.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This technology relates to a signal direction display processing device, a signal processing system, a signal direction display processing method, and a program for the signal direction display processing method. In particular, it relates to a process for displaying the direction of arrival of a signal emitted by a target object received by a receiver. [Background technology]

[0002] For example, there are signal processing devices (sonar devices) that perform phase correction based on received signals such as sound received by a receiver array, such as a sonar with multiple receivers, to identify a target object and estimate the target's direction. Based on the data obtained from the signal processing device, the horizontal direction of arrival and elevation angle of the signal emitted by the target, as well as the direction of movement and the amount of change in direction of the target in the horizontal direction, are displayed on a display device.

[0003] One method for displaying the approaching horizontal bearing on a display device is the ELAZ (Elevation-Azimuth) display method, which shows the signal level in varying shades for each horizontal bearing and elevation angle. Another method is to display the BTR (Bearing-Time-Recorder) display, which shows the signal intensity for each horizontal bearing in varying shades over time, according to a specified elevation angle (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-091300 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Here, we will explain the ELAZ display and the BTR display corresponding to the specified elevation angle. The signal processing device performs horizontal phase shaping on the signal received by the receiver array for multiple different elevation angles, and generates horizontal phase shaping result BL (Bearing-Level) data for each elevation angle. The horizontal phase shaping result BL for each elevation angle generated by the signal processing device is arranged in order of elevation angle to form a 2D data of elevation angle × horizontal direction. Furthermore, the signal intensity is converted to grayscale, and an ELAZ display is performed with horizontal direction on the horizontal axis and elevation angle on the vertical axis. On the other hand, the horizontal phase shaping result BL at the specified elevation angle is arranged in time series to form 2D data, and the signal intensity is converted to grayscale, and a BTR display is performed with horizontal direction on the horizontal axis and time series on the vertical axis. Therefore, the operator can understand the direction of arrival of the signal emitted from the target by checking the ELAZ display displayed on the display device. In addition, the operator can understand the direction of movement and the amount of change in direction of the target in the horizontal direction from the BTR display.

[0006] Figure 1 shows an example of an ELAZ display. The receiver array is a planar array in which multiple receivers are arranged in a rectangular shape over a horizontal array length of 40m and an elevation array length of 3m. The horizontal broadside of the planar array is 90 degrees, and the elevation broadside is 0 degrees, with beam spacing of 1 degree in both the horizontal and elevation directions. The display in Figure 1 is an ELAZ display of a signal received by the planar array with an arrival horizontal azimuth of 60 degrees and an elevation angle of 40 degrees, and a signal emitted from a target with an arrival horizontal azimuth of 30 degrees and an elevation angle of 20 degrees.

[0007] FIG. 2 is a diagram showing the horizontal phasing processing results BL for every 10 degrees of elevation angle in the ELAZ display according to FIG. 1. Among the level peaks shown in FIG. 2, the peak at the horizontal azimuth of 60 degrees in the BL data for an elevation angle of 40 degrees and the peak at the horizontal azimuth of 30 degrees in the BL data for an elevation angle of 20 degrees are peaks of the signal level resulting from the true target. On the other hand, it can be seen that with respect to the horizontal azimuth of the peak from the true target, peaks are also displayed at different horizontal azimuths for each elevation angle BL. These peaks are peaks from false targets generated by the spread of the main lobes of the target signals at the 40-degree elevation angle and the 20-degree elevation angle. For this reason, when the horizontal phasing processing results BL are arranged in time series and BTR display is performed for each elevation angle, the displayed incoming horizontal azimuth of the target differs depending on the designated elevation angle.

[0008] As described above, when display is provided such that peaks from the target appear at different horizontal azimuths depending on elevation angle due to the spread of the main lobe in the target signal, there is a possibility that an operator may misrecognize the incoming horizontal azimuth of the target, the elevation angle, the number of targets, and the like.

[0009] Accordingly, there has been a demand for realizing a signal azimuth display processing apparatus, a signal processing system, a signal azimuth display processing method, and a program for the signal azimuth display processing method that can perform processing for more clearly displaying the incoming horizontal azimuth and elevation angle of a target, and the number of targets. [Means for Solving the Problem]

[0010] A signal azimuth display processing apparatus according to the present disclosure is a signal azimuth display processing apparatus that performs processing for displaying a horizontal azimuth and an elevation angle at which a target signal emitted from a target arrives, the signal azimuth display processing apparatus comprising: an interpolation processing unit that performs conversion processing into two-dimensional conversion data in a conical coordinate system based on a horizontal phasing processing result of a target signal represented by coordinates in a horizontal azimuth-elevation coordinate system formed by a horizontal azimuth and an elevation angle, the two-dimensional conversion data against , The system performs a scan in a direction perpendicular to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal reaches its maximum. where the target signal becomes maximal One or morea target detection processing unit that generates data pertaining to arrival direction information of a target signal in a conical coordinate system including a signal level; a coordinate conversion processing unit that converts arrival direction information of the target signal obtained by the conical coordinate system into arrival direction information of the target signal obtained by a horizontal direction-elevation coordinate system; based on arrival direction information obtained by the horizontal direction-elevation coordinate system, One or more and a display processing unit that generates display data for causing a display device to plot the signal level at positions of corresponding horizontal direction and elevation and display the plotted signal level on the display device.

[0011] Furthermore, the disclosed signal processing system comprises: a receiver array having a plurality of receivers and outputting received signals pertaining to reception; a signal processing device that performs phasing processing on a target signal emitted from a target based on the received signals; the above signal direction display processing device; and a display device that performs display based on a display signal including display data generated through processing performed by the signal direction display processing device.

[0012] Furthermore, the disclosed signal direction display processing method is a signal direction display processing method for performing processing of displaying a horizontal direction and an elevation at which a target signal emitted from a target arrives, the method comprising: an interpolation processing step of performing conversion processing into two-dimensional conversion data of the conical coordinate system based on a horizontal phasing processing result of the target signal represented by coordinates of the horizontal direction-elevation coordinate system formed by a horizontal direction and an elevation; the two-dimensional conversion data against , The system performs a scan in a direction perpendicular to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal reaches its maximum. where the target signal reaches a maximum One or more a target detection processing step of generating data pertaining to arrival direction information of the target signal in a conical coordinate system including a signal level; a coordinate conversion processing step of converting arrival direction information of the target signal obtained by the conical coordinate system into arrival direction information of the target signal obtained by the horizontal direction-elevation coordinate system; based on arrival direction information obtained by the horizontal direction-elevation coordinate system, One or more and a display processing step of generating display data for causing a display device to plot the signal level at positions of corresponding horizontal direction and elevation and display the plotted signal level on the display device.

[0013] Furthermore, the program for the signal direction display processing method disclosed is a program for the signal direction display processing method that performs processing to display the horizontal direction and elevation angle from which a target signal emitted by a target arrives, and comprises an interpolation processing step that performs conversion processing to 2D converted data in a conical coordinate system based on the horizontal phase alignment processing result of the target signal expressed in coordinates of a horizontal direction-elevation coordinate system based on the horizontal direction and elevation angle, and 2D converted data against , The system performs a scan in a direction perpendicular to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal reaches its maximum. A target detection processing step generates data relating to the direction of arrival information of the target signal in a conical coordinate system that includes the signal level at which the target signal is maximum; a coordinate transformation processing step converts the direction of arrival information of the target signal in the conical coordinate system into the direction of arrival information of the target signal in a horizontal azimuth-elevation coordinate system; and based on the direction of arrival information in the horizontal azimuth-elevation coordinate system, One or more This involves having a computer perform a display processing step that generates display data, plotting the signal level at the corresponding horizontal azimuth and elevation angle positions and displaying it on a display device. [Effects of the Invention]

[0014] According to the disclosed signal direction display processing device, based on the horizontal phase alignment processing result obtained by aligning the target signal, the maximum signal level, horizontal direction, and elevation angle in the target signal can be detected, and display data can be generated and displayed on a display device. Therefore, the direction of the target will not be displayed as the spread of the main pole of the target signal. Thus, the operator can prevent misidentification of the target's approaching horizontal direction and approaching elevation angle, as well as misidentification of the number of targets. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows an example of ELAZ display. [Figure 2] This figure shows the horizontal phase adjustment results BL for every 10 degrees of elevation angle in the ELAZ display shown in Figure 1. [Figure 3] This diagram illustrates the spread of the principal pole in the target signal. [Figure 4] This diagram illustrates the shape of the principal pole in the target signal after coordinate transformation. [Figure 5] This diagram shows the positional relationship between the target and the receiver array in various coordinate systems. [Figure 6] This figure shows the configuration of a signal processing system centered on the signal direction display processing device 300 according to Embodiment 1. [Figure 7] This figure shows an example of a display shown by the display device 400 according to Embodiment 1. [Figure 8] This diagram illustrates the processing flow of the signal direction display processing device 300 according to Embodiment 1. [Figure 9] This figure shows an example of processing in the display processing unit 350 of Embodiment 1. [Figure 10] This figure illustrates the configuration of the receiver array 100 in the signal processing system according to Embodiment 2. [Figure 11] This figure shows an example of horizontal phase shaping output for each elevation angle using a planar array curved in the y-axis direction in the signal processing system according to Embodiment 2. [Figure 12] This figure illustrates the θ-φ coordinate transformation table 371 according to Embodiment 2. [Figure 13] This diagram illustrates the process for creating the θ-φ coordinate transformation table 371 according to Embodiment 2. [Figure 14] This figure shows an example of the beam response displayed by ELAZ at the target direction (θT(m),0). [Figure 15] This diagram shows the configuration of the signal processing system according to Embodiment 2. [Figure 16] This diagram illustrates the signal level creation process in the beam response processing unit 380 of Embodiment 2. [Modes for carrying out the invention]

[0016] The following description will explain the signal direction display processing device and other components according to the embodiments, with reference to the drawings. In the following drawings, components with the same reference numerals are the same or equivalent and are common throughout the entire text of the embodiments described below. Also, the size relationships of the components in the drawings may differ from those of the actual components. Furthermore, the forms of the components shown throughout the specification are merely examples and are not limited to the forms described in the specification. It is not necessary to include all the equipment described in the specification. In particular, the combinations of components are not limited to the combinations in each embodiment, and components described in other embodiments can be applied to other embodiments. Also, if there is no need to distinguish or specify multiple similar devices that are distinguished by subscripts, the reference numerals and subscripts may be omitted.

[0017] Embodiment 1. In the signal processing system of Embodiment 1, which processes signals obtained from sound waves or other signals emitted by a target (hereinafter referred to as the target signal) and displays the direction of arrival, an overview of the display processing performed by the signal direction display processing device 300, which will be described later, will be explained.

[0018] Figure 3 illustrates the spread of the main pole in the target signal. For a signal processing system to display the direction of arrival of the target signal, it is necessary to obtain the values ​​for the horizontal direction and elevation angle corresponding to the peak of the signal level in the target signal. As shown in Figure 3, the relationship between the horizontal direction θ [rad] and the elevation angle φ [rad] of the phase-corrected target signal is displayed graphically based on a polar coordinate system where the horizontal axis is the horizontal direction θ [rad] and the vertical axis is the elevation angle φ [rad]. In this case, the target signal is displayed in the graph with the main pole curving and spreading in the elevation direction. Therefore, when the signal processing system detects the peak of the signal level in the target signal, it must scan along the spread of the target signal. Here, the polar coordinate system with horizontal direction θ and elevation angle φ is referred to as the horizontal direction-elevation coordinate system.

[0019] Figure 4 illustrates the shape of the principal pole in the target signal after coordinate transformation. The principal pole of the phase-corrected target signal is transformed from the horizontal azimuthal-elevation coordinate system shown in Figure 3 to the polar coordinate system shown in Figure 5, where sinξ is the horizontal axis and ψ is the vertical axis. As shown in Figure 4, the coordinate transformation causes the principal pole of the target signal to be displayed as a straight line along the ψ direction. Therefore, the peak of the target signal can be detected by scanning along the straight line along the ψ direction. Here, the polar coordinate system with sinξ on the horizontal axis and ψ on the vertical axis is referred to as a conical coordinate system.

[0020] In a conical coordinate system, to calculate the peak point of the signal level indicating the direction of arrival of the target signal, it is necessary to convert 2D data with equal intervals of (θ,φ) to 2D data with equal intervals of (sinξ,ψ). Therefore, in Embodiment 1, the signal direction display processing device 300, described later, obtains (θ',φ') coordinates corresponding to equal intervals of (sinξ,ψ). The signal direction display processing device 300 also interpolates the 2D data with equal intervals of (θ,φ) and arranges the interpolated values ​​at equal intervals in the 2D data with equal intervals of (sinξ,ψ). Subsequently, the signal direction display processing device 300 estimates the coordinates of the peak point in the conical coordinate system (sinξ,ψ). Then, the signal direction display processing device 300 converts the coordinates of the peak point (sinξ,ψ) back to (θ,φ) coordinates to obtain the direction of arrival of the target (θ,φ).

[0021] Figure 5 shows the positional relationship between the target and the receiver array 100 in various coordinate systems. Next, the principle of coordinate transformation between the horizontal azimuth-elevation coordinate system and the conical coordinate system will be explained. As shown in Figure 5, a rectangular planar array is assumed to be placed in the xz plane (y=0) as the receiver array 100, which will be described later. The directivity when the signal received by the planar array is phased to the horizontal azimuth θ (angle from the x-axis in the xy-plane) and elevation angle φ (angle from the xy-plane) is assumed to be formed along a conical surface with an angle ξ from the x-axis. In this case, if the coordinates in the conical surface at a distance r=1 from the vertex of the cone are (sinξ,ψ) in the conical coordinate system, then the relationship between the point (θ,φ) in the horizontal azimuth-elevation coordinate system and the point (sinξ,ψ) in the conical coordinate system is expressed by the following equations (1) and (2).

[0022]

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[0023]

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[0024] In the space of a conical coordinate system, the principal pole of the target signal is orthogonal to sinξ. Conversely, the transformation from a conical coordinate system to a horizontal azimuth-elevation coordinate system is expressed by equations (3) and (4). Based on the above relationship, the signal processing system of Embodiment 1 transforms the data related to phase adjustment processing from a horizontal azimuth-elevation coordinate system to a conical coordinate system to detect the peak point of the target signal. Then, by transforming the peak point from a conical coordinate system to a horizontal azimuth-elevation coordinate system, display processing is performed to clarify the horizontal azimuth of the target, etc.

[0025]

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[0026]

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[0027] Figure 6 is a diagram showing the configuration of a signal processing system centered on a signal direction display processing device 300 according to Embodiment 1. As shown in Figure 6, the signal processing system of Embodiment 1 includes a receiver array 100, a signal processing device 200, a signal direction display processing device 300, and a display device 400.

[0028] The receiver array 100 is a device such as a sonar that has multiple receivers (not shown) that receive signals, and transmits the received signals received by the receivers to the signal processing device 200. The received signals include target signals emitted by the target. Here, the receiver array 100 in Embodiment 1 is assumed to be a planar array in which multiple receivers are arranged in a rectangular shape. As shown in Figure 5 above, the receivers are arranged on the xz plane in a Cartesian coordinate system with the center of the planar array as the origin.

[0029] The signal processing device 200 includes a phase adjustment device and performs phase adjustment on the received signals from the receiver array 100 at set elevation angles. The signal processing device 200 then processes the horizontal phase adjustment result BF n The system outputs a phase-correcting signal containing data for (m)(n=1~N, m=1~M). Here, N is the phase-correcting elevation angle, and M is the set horizontal azimuth number.

[0030] The signal orientation display processing device 300 includes an input terminal section 310, an ELAZ interpolation processing section 320, a target detection processing section 330, a coordinate transformation processing section 340, a display processing section 350, an output terminal section 360, and a storage section 370.

[0031] The input terminal 310 is a terminal that receives the phase correction signal output by the signal processing device 200. As described above, the horizontal phase correction processing result BF in the phase correction signal is received via the input terminal 310. n The data (m) is input to the ELAZ interpolation processing unit 320. In Figure 6, the input terminal unit 310 is shown to have N input terminals, but the number of input terminals is not limited.

[0032] The ELAZ interpolation processing unit 320 processes the horizontal phase shaping result BF n Based on the data (m), interpolation and transformation processing are performed to obtain the 2D transformed data EL. cone The (p,q)(p=1~P, q=1~Q) is generated. Here, P is the number of data points in the sinξ axis direction, and Q is the number of data points in the ψ axis direction. The ELAZ interpolation processing unit 320 has a sorting processing unit 321, a coordinate transformation source calculation processing unit 322, and a transformation processing unit 323. The sorting processing unit 321, the coordinate transformation source calculation processing unit 322, and the transformation processing unit 323 will be described later.

[0033] The target detection processing unit 330 processes the 2D conversion data EL cone Based on (p,q), a target detection process is performed to detect the target and generate data on the arrival direction of the target signal in a conical coordinate system (hereinafter referred to as conical coordinate system arrival direction information). Here, the conical coordinate system arrival direction information consists of sinξ information CK(t) and ψ information CP(CK(t)) related to the arriving target signal, and the signal level CD(t) (t=1~T). T is the number of signals detected (the same applies hereafter).

[0034] The coordinate transformation processing unit 340 performs coordinate transformation processing from the conical coordinate system to the horizontal azimuth-elevation coordinate system based on the data of the arrival direction information in the conical coordinate system. The coordinate transformation processing unit 340 then performs a coordinate transformation processing step to generate data of arrival direction information in the horizontal azimuth-elevation coordinate system (hereinafter referred to as the azimuth coordinate system arrival direction information). The azimuth coordinate system arrival direction information consists of horizontal azimuth information CS(t) and elevation information CH(t) related to the arriving target signal, and the corresponding signal level CD(t) (t=1~T).

[0035] The display processing unit 350 performs display processing based on the data of the azimuth coordinate system arrival direction information. The display processing unit 350 performs a display processing step to generate display data using a BTR display that represents the time change of the arrival horizontal direction and an ETR (Elevation-Time-Recorder) display that represents the time change of the arrival elevation angle. The output terminal unit 360 then outputs a display signal containing the display data processed and generated by the display processing unit 350.

[0036] Here, the signal direction display processing device 300 typically includes a control processing unit, such as a computer centered around a CPU (Central Processing Unit), as hardware. The aforementioned ELAZ interpolation processing unit 320, target detection processing unit 330, coordinate transformation processing unit 340, and display processing unit 350 execute pre-programmed steps for the processing methods performed by each unit, as determined by the control processing unit. Here, the program is stored, for example, in the storage unit 370, which will be described later. However, the hardware configuration is not limited to this configuration, and each unit may be configured with separate, dedicated equipment.

[0037] The storage unit 370 stores data necessary for each part of the signal direction display processing device 300 to perform its processing. The storage unit 370 stores data used by the ELAZ interpolation processing unit 320, target detection processing unit 330, coordinate transformation processing unit 340, and display processing unit 350 when each part performs its processing. The storage unit 370 has a volatile storage device (not shown), such as a random access memory (RAM), which can temporarily store data, and a non-volatile auxiliary storage device (not shown), such as a flash memory, which can store data long-term. Furthermore, as described above, the storage unit 370 stores a program, and the ELAZ interpolation processing unit 320, target detection processing unit 330, coordinate transformation processing unit 340, and display processing unit 350 execute processing steps based on the program to realize the processing performed by each part.

[0038] Figure 7 shows an example of a display shown by the display device 400 according to Embodiment 1. Here, Figure 7(a) shows the BTR display, and Figure 7(b) shows the ETR display. In Figure 7, 0 [sec] on the vertical axis represents the most recent time. The display device 400 performs the display based on the display signal sent from the signal direction display processing device 300.

[0039] FIG. 8 is a diagram for explaining the processing flow of the signal direction display processing apparatus 300 according to the first embodiment. Next, the processing steps performed by the signal direction display processing apparatus 300 in the first embodiment will be described in further detail.

[0040] The ELAZ interpolation processing section 320 performs processing on the horizontal phasing result BF in the phased signal transmitted via the input terminal section 310 n data of (m). To implement the interpolation processing step, the ELAZ interpolation processing section 320 includes a rearrangement processing section 321, a coordinate conversion source calculation processing section 322, and a conversion processing section 323 as described above.

[0041] The rearrangement processing section 321 of the ELAZ interpolation processing section 320 processes the horizontal phasing result BF n data of (m) by performing rearrangement processing that rearranges the data in the elevation direction (step S1). Here, the two-dimensional data in the horizontal direction-elevation angle coordinate system rearranged by the rearrangement processing section 321 is referred to as rearranged data EL θ-φ (m,n). The rearranged data EL θ-φ (m,n) is represented by the following formula (5).

[0042] [Mathematical Expression]

[0043] On the other hand, the coordinate conversion source calculation processing section 322 performs coordinate conversion source calculation processing to obtain coordinates (θ'(p,q), φ'(p,q)) in the horizontal direction-elevation angle coordinate system, which are coordinate conversion sources for points (ξ(p), ψ(q)) in the conical coordinate system that is the conversion destination (step S2). The coordinate conversion source calculation processing section 322 can obtain the coordinates (θ'(p,q), φ'(p,q)) based on the following formulas (6) and (7) which use the principles of formulas (3) and (4) described above. Here, the coordinate conversion source calculation processing section 322 may perform the coordinate conversion source calculation processing before the rearrangement processing to obtain the coordinates (θ'(p,q), φ'(p,q)) in advance.

[0044] [Mathematical Expression]

[0045]

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[0046] The conversion processing unit 323 processes the sorted data EL θ-φ Based on (m,n), the level of the target signal at the coordinates (θ'(p,q),φ'(p,q)) obtained by the coordinate transformation source calculation processing unit 322 is determined by interpolation (step S3). Here, in Embodiment 1, the transformation processing unit 323 performs interpolation using the bilinear method. Therefore, the transformation processing unit 323 calculates the level of the target signal at the four nearest neighbors [EL] for the coordinates (θ'(p,q),φ'(p,q)). θ-φ (m,n),EL θ-φ (m+1,n),EL θ-φ (m,n+1),EL θ-φ Interpolation processing is performed based on (m+1, n+1). The transformation processing unit 323 sorts the data EL representing the level of the horizontal azimuth-elevation coordinate system. θ-φ Interpolation is performed based on (m,n) to create 2D transformed data EL representing the level of a point (sinξ(p),ψ(q)) in a conical coordinate system. cone The coordinate system can be transformed to (p,q).

[0047] 2D conversion data EL cone (p,q) is calculated by the following equation (8). Here, BIL[] represents the interpolation process using the bilinear method. The first argument is the 2D data from which the coordinate transformation was performed, and the second argument is the coordinate obtained by interpolation. In this way, the ELAZ interpolation processing unit 320 calculates the 2D transformed data EL cone Generates (p,q). 2D transformation data EL cone (p,q) is used in the processing performed by the target detection unit 330.

[0048]

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[0049] The target detection processing unit 330 processes the two-dimensional conversion data EL obtained by the conversion processing unit 323. cone For (p,q), a maximum value processing is performed to find the maximum level in the ψ direction for each sinξ(p) (step S4). The target detection processing unit 330 calculates the maximum level CL(p) and the maximum elevation angle CP(p) based on the following equation (9). Here, the maximum level CL(p) is the maximum value of the calculated level. The maximum elevation angle CP(p) is the elevation angle ψ from which the maximum level CL(p) was calculated. MAX[] represents the maximum value processing, the first argument is the data to be processed, and the second argument represents the direction of the coordinate axis on which the maximum value processing is performed.

[0050]

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[0051] Furthermore, the target detection processing unit 330 performs a maximal value processing (step S5) by scanning the one-dimensional maximum level CL(p) calculated by equation (9) in the sinξ direction to find the maximum value (maximal level). The target detection processing unit 330 also calculates the signal level CD(t) and sinξ information CK(t) based on the following equation (10). Here, the signal level CD(t) is the maximum value of the level. The sinξ information CK(t) is the sinξ when the signal level CD(t) is obtained. PK[] represents the maximal value processing. The arguments of PK[] represent the data to be processed for the maximal value processing. The target detection processing unit 330 further finds ψ information CP(CK(t)) which is the maximum elevation angle CP(p) at the maximum value. Here, for example, if the receiver array 100 receives target signals from two or more target objects, two or more maximal values ​​may be found.

[0052]

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[0053] The coordinate transformation processing unit 340 performs a coordinate transformation on the sinξ information CK(t) and ψ information CP(CK(t)) to obtain a transformed horizontal azimuth θ”(t) and a transformed elevation angle φ”(t) (step S6). The transformed horizontal azimuth θ”(t) and transformed elevation angle φ”(t) are expressed by the following equations (11) and (12).

[0054]

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[0055]

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[0056] Then, the coordinate transformation processing unit 340 uses the transformed horizontal azimuth θ”(t) and transformed elevation angle φ”(t) as the target horizontal azimuth information CS(t) and elevation angle information CH(t), as shown in equations (13) and (14) below.

[0057]

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[0058]

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[0059] The display processing unit 350 performs display processing to generate display data based on the horizontal azimuth information CS(t), elevation angle information CH(t), and signal level CD(t) (step S7). First, it converts the signal level CD(t) processed by the target detection processing unit 330 into a brightness value. Then, on the BTR, the display processing unit 350 performs display processing to generate display data that plots points with brightness corresponding to the signal level CD(t) at positions corresponding to the horizontal azimuth information CS(t) obtained by the coordinate transformation processing unit 340. On the ETR, the display processing unit 350 also performs display processing that plots points with brightness corresponding to the signal level CD(t) at positions corresponding to the elevation angle information CH(t) obtained by the coordinate transformation processing unit 340. For example, if the signal level CD(t) is high, it plots points with brightness that will be displayed brighter.

[0060] Figure 9 shows an example of processing in the display processing unit 350 of Embodiment 1. In Figure 9, the operation of the display processing in the display processing unit 350 is shown using BTR as an example. On the BTR, when the display processing unit 350 plots a new luminance point corresponding to the signal level CD(t) at a position corresponding to the horizontal direction information CS(t), it erases the point (luminance value data) located at the uppermost grid (-30 [sec]) on the vertical axis shown in Figure 9. The other points are then replotted on the grid one level higher. The display processing unit 350 then plots a new point at the position corresponding to the horizontal direction information CS(t) on the lowermost grid (0 [sec]) shown in Figure 9. For ETR display, the display processing unit 350 similarly plots a new point based on the elevation angle information CH(t) instead of the horizontal direction information CS(t) in BTR display.

[0061] Each part of the signal direction display processing device 300 repeats the above processing and outputs a display signal from the output terminal section 360. The display device 400 displays BTR and ETR based on the display data in the display signal sent from the signal direction display processing device 300. The operator determines the target position and number of targets based on the screen of the display device 400.

[0062] As described above, in the signal processing system of Embodiment 1, the signal processing device 200 performs horizontal phase shaping processing on the received signals of the planar array which forms the receiver array 100 for each elevation angle, and the horizontal phase shaping processing result BF n The data for (m) is obtained. Then, the ELAZ interpolation processing unit 320 of the signal direction display processing unit 300 processes the horizontal phase adjustment result BF n For (m), EL is a 2D transformation data from the horizontal azimuth-elevation coordinate system to the conical coordinate system. cone The signal is converted to (p,q) and the spread of the main pole of the target signal is made orthogonal to the sinξ axis. The target detection processing unit 330 also performs a maximum value processing to obtain the maximum value in the ψ direction for each sinξ axis and calculates the maximum level CL(p). The target detection processing unit 330 further performs a maximum value processing to find the maximum value in the sinξ direction and calculates the signal level CD(t), sinξ information CK(t), and ψ information CP(CK(t)) as conical coordinate system arrival direction information. The coordinate transformation processing unit 340 transforms the conical coordinate system arrival direction information and generates data for azimuth coordinate system arrival direction information (horizontal direction information CS(t) and elevation angle information CH(t)). The display processing unit 350 then performs display processing and sends the obtained display signal to the display device 400, which displays it in BTR display and ETR display. Therefore, the signal direction display processing device 300 can display the arrival horizontal direction and arrival elevation angle of the target signal in a time series. Thus, the signal direction display processing device 300 can clarify the direction in which the signal level is maximum in the conical coordinate system (the direction in which the target is located), and then return it to the horizontal direction-elevation coordinate system and display it on the display device 400. Consequently, the operator can prevent misrecognition of the arrival horizontal direction and arrival elevation angle of the target, as well as misrecognition of the number of targets.

[0063] Embodiment 2. Figure 10 is a diagram illustrating the configuration of the receiver array 100 in the signal processing system according to Embodiment 2. In Embodiment 1, the receiver array 100 was described as a rectangular planar array unfolded in the xz plane. In the signal processing system of Embodiment 2, the receiver array 100 is assumed to be composed of a rectangular planar array curved in the positive or negative direction of the y-axis, as shown in Figure 10.

[0064] Figure 11 shows an example of horizontal phase shaping output for each elevation angle using a planar array curved in the y-axis direction in the signal processing system according to Embodiment 2. As shown in Figure 11, two-dimensional data on a curved surface generated by a curved planar array cannot be transformed from a horizontal azimuth-elevation coordinate system, represented by horizontal azimuth θ and elevation angle φ based on equations (1) to (4), to a conical coordinate system represented by sinξ and ψ.

[0065] Therefore, in the signal processing system of Embodiment 2, instead of performing the coordinate transformation processing that the ELAZ interpolation processing unit 320 performed in Embodiment 1, beam response processing is performed using the numerical calculation results of the beam response of the planar array. Specifically, the horizontal azimuth θ at each point of the spread of the target signal is determined in advance and converted into table-format data, which is stored in the storage unit 370 as the θ-φ coordinate transformation table 371, described later. Then, a signal level generation process is performed to determine the signal level at each position by referring to the θ-φ coordinate transformation table 371.

[0066] Figure 12 illustrates the θ-φ coordinate transformation table 371 according to Embodiment 2. Figure 13 illustrates the process for creating the θ-φ coordinate transformation table 371 according to Embodiment 2. The θ-φ coordinate transformation table 371 is obtained based on the following steps 1 to 3.

[0067] Figure 14 shows the target bearing (θ). T This figure shows an example of the beam response displayed by ELAZ at (m),0). First, the target azimuth (θ) is displayed on a planar array curved in the y-axis direction, which is the receiver array 100. TThe phase alignment direction (θ) when the target signal arrives from (m),0) B (m), φ B Calculate the beam response ELAZ for (n) (Step 1).

[0068] From the calculated beam response ELAZ, the elevation angle φ B For every (n) unit, the maximum value is processed horizontally to obtain the horizontal direction θ corresponding to the maximum value. Then, the obtained horizontal direction θ is converted to the horizontal direction θ in the θ-φ coordinate transformation table 371, as shown in Figure 12(a). C The values ​​of the (m,n) items are stored as data (Step 2). The relationship between the corresponding horizontal azimuth θ and elevation angle φ is shown in Figure 12(b).

[0069] At this time, as shown in Figure 13, if the value obtained by the maximum value processing is below a predetermined threshold, the horizontal azimuth θ C The value for the (m,n) item will be a null value. Horizontal azimuth θ C The values ​​for the (m,n) items are obtained based on the following formula (15). Here, in formula (15), NULL[] indicates that if the value of the first argument is less than the value of the second argument, a NULL value is assigned.

[0070]

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[0071] Then, for each m (m=1 to M, where M is the horizontal azimuth number), the aforementioned steps 1 and 2 are repeated to create the θ-φ coordinate transformation table 371 (step 3).

[0072] As described above, in the second embodiment, the signal direction display processing device 300 stores the θ-φ coordinate transformation table 371 as data in the storage unit 370. Then, instead of the ELAZ interpolation processing unit 320 performing coordinate transformation processing based on equation (11) in the first embodiment, the signal direction display processing device 300 performs processing based on the horizontal direction θ obtained by searching the θ-φ coordinate transformation table 371 stored in the storage unit 370.

[0073] Figure 15 shows the configuration of the signal processing system according to Embodiment 2. In Figure 15, the processing units and other components that have the same reference numerals as in Figure 6 perform the same processing as in Embodiment 1. As shown in Figure 15, the signal direction display processing device 300 in Embodiment 2 has a beam response processing unit 380 instead of the ELAZ interpolation processing unit 320. The target detection processing unit 331 performs a target detection processing step that generates data related to the direction of arrival information of the direction coordinate system. The storage unit 370 has the θ-φ coordinate transformation table 371 as data, as described above.

[0074] The beam response processing unit 380 calculates the horizontal phase shaping result BF based on the θ-φ coordinate transformation table 371 stored in the memory unit 370. n (m) horizontal azimuth θ C The 2D signal level EQθ-φ(m,n), which is 2D data relating to the signal level corresponding to (m,n), is obtained. The target detection processing unit 331 also detects the target signal emitted by the target from the 2D signal level EQθ-φ(m,n) data and performs a beam response processing step to generate horizontal azimuth information CS(t), elevation angle information CH(t), and signal level CD(t) of the arriving target signal.

[0075] Next, the processing operation of the signal orientation display processing device 300 in Embodiment 2 will be described in more detail.

[0076] Figure 16 is a diagram illustrating the signal level generation process in the beam response processing unit 380 of Embodiment 2. The beam response processing unit 380 generates the horizontal azimuth θ from the θ-φ coordinate transformation table 371 stored in the storage unit 370. CThe value at (m,n) is read out. Then, the beam response processing unit 380 processes the horizontal phase correction result BF included in the phase correction signal. n Based on the (m) data, horizontal azimuth θ C 2D signal level EQ corresponding to (m,n) θ-φ (m,n) is obtained based on the following equation (16). 2D signal level EQ θ-φ (m,n) is the horizontal azimuth θ C Horizontal phase alignment processing result BF at (m,n) n (m)

[0077]

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[0078] The target detection processing unit 331 controls the EQ of the two-dimensional signal acquired by the beam response processing unit 380. θ-φ For (m,n), a maximum value processing is performed to find the maximum level at each elevation angle for each horizontal azimuth θ, based on the following equation (17). Here, the maximum level CL(m) is the maximum level. The maximum elevation angle index CI(m) is the matrix EQ of the 2D signal level corresponding to the maximum level CL(m). θ-φ Therefore, the column number n representing the elevation angle is stored as the index. Then, MAX[] is used for maximum value processing; the first argument is the data to be processed for maximum value processing, and the second argument represents the elevation angle at which the maximum value processing is performed.

[0079]

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[0080] The target detection processing unit 331 further performs a local maximum value processing on the one-dimensional data, maximum level CL(m), to find the local maximum value with respect to the horizontal direction θ. The target detection processing unit 331 obtains the signal level CD(t) and the horizontal direction index CJ(t) based on the following equation (18). Here, the signal level CD(t) is the local maximum value of the level, as described above. The horizontal direction index CJ(t) stores the sequence number m of the one-dimensional data, maximum level CL(m), which represents the horizontal direction θ for which the signal level CD(t) was obtained, as the index. Here, t = 1 to T (where T is the number of local maximum values ​​detected = number of signals detected).

[0081]

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[0082] The target detection processing unit 331 then obtains the target's horizontal azimuth information CS(t) and elevation angle information CH(t) based on the following equations (19) and (20). The signal level CD(t), target's horizontal azimuth information CS(t), and elevation angle information CH(t) obtained in this manner are then displayed in the display processing unit 350. The display processing in the display processing unit 350 is the same as that described in Embodiment 1.

[0083]

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[0084]

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[0085] As described above, in the signal processing system of Embodiment 2, the storage unit 370 stores a θ-φ coordinate transformation table 371, which uses the horizontal azimuth θ at each point in the spread of the target signal as data. Then, the beam response processing unit 380 uses the θ-φ coordinate transformation table 371 to obtain the horizontal azimuth θ from the horizontal phase correction processing result BFm(m) included in the phase correction signal from the signal correction processing unit 200. C2D signal level EQ corresponding to (m,n) θ-φ (m,n) is obtained. In addition, the target detection processing unit 331 performs a 2D signal level EQ. θ-φ The system detects the target signal emitted by the target from the (m,n) data and generates horizontal azimuth information CS(t), elevation angle information CH(t), and signal level CD(t) of the arriving target signal. The display processing unit 350 then performs display processing and sends the resulting display signal to the display device 400, which displays it on the BTR display and ETR display. As a result, the signal azimuth display processing unit 300 can display the arriving horizontal azimuth and elevation angle of the target signal in time series. Therefore, by clearly indicating the azimuth where the signal level is maximum (the azimuth where the target is located) and displaying it on the display device 400, operators can prevent misidentification of the arriving horizontal azimuth and elevation angle of the target, as well as misidentification of the number of targets. In particular, in the signal processing system of Embodiment 2, even when it is not possible to perform processing using coordinate transformation, such as with a receiver array 100 composed of a curved planar array, maximum value processing can be performed without performing coordinate transformation processing. Therefore, the azimuth of the target can be clearly displayed.

[0086] Embodiment 3. In the embodiment 1 described above, the ELAZ interpolation processing unit 320 calculates the points (θ'(p,q),φ'(p,q)) obtained by interpolation using coordinate transformation equations (6) and (7), but is not limited to this. For example, the points (θ'(p,q),φ'(p,q)) may be calculated in advance by calculation or other means and stored in the storage unit 370 as table data. The ELAZ interpolation processing unit 320 may then search for the corresponding points (θ'(p,q),φ'(p,q)) from the storage unit 370.

[0087] Furthermore, in the embodiment 1 described above, the transformation processing unit 323 performed interpolation using the bilinear method, but it may be implemented using other interpolation methods. For example, the transformation processing unit 323 may perform interpolation using the bicubic method with respect to the coordinate (θ'(p,q),φ'(p,q)) using the 16 nearest neighbors. Although the processing load increases when using the bicubic method, it is possible to calculate a more accurate level.

[0088] Furthermore, while the receiver array 100 in Embodiment 2 described above is a planar array curved in the y-axis direction, it is not limited to this. If the horizontal orientation of points spreading on the curve of the main pole of the target signal can be calculated using the beam response of the receiver array 100, it can also be applied to planar arrays whose curvature direction is other than the y-axis direction. In addition, the signal orientation display processing device 300 configured with a processing unit like that in Embodiment 2 can be used not only with receiver arrays 100 whose shape does not allow for analytical coordinate transformation, but also when receiving signals with receiver arrays 100 whose shape allows for analytical coordinate transformation, as in Embodiment 1.

[0089] Furthermore, while the receiver array 100 described in Embodiments 1 and 2 above was assumed to have multiple receivers arranged in a rectangular shape, the arrangement of the receiver array 100 is not limited to a rectangular shape. For example, a receiver array 100 in which receivers are arranged in a disc shape or an elliptical disc shape can also be applied.

[0090] Furthermore, while the target signal emitted from the target was explained using a narrowband signal as an example, it is not limited to this. For example, if the target signal is broadband, the signal processing device 200 performs phase shaping and other processing in advance in the frequency direction, and then sends the shaped signal to the signal direction display processing device 300. This allows the signal direction display processing device 300 to perform the processing described in Embodiments 1 and 2.

[0091] Furthermore, while the signal processing systems described in Embodiments 1 and 2 above consist of a signal processing device 200, a signal direction display processing device 300, and a display device 400 as separate devices, the system is not limited to this configuration. For example, the signal direction display processing device 300 and the display device 400 may be configured as an integrated device. Alternatively, the signal processing device 200, the signal direction display processing device 300, and the display device 400 may be configured as an integrated device. [Explanation of Symbols]

[0092] 100 receiver array 200 Signal Processing Equipment 300 Signal Direction Indication Processing Device 310 Input terminal section 320 ELAZ Interpolation Processing Unit 321 Sorting Processing Unit 322 Coordinate Transformation Source Calculation Processing Unit 323 Conversion Processing Unit 330,331 Target detection processing unit 340 Coordinate Transformation Processing Unit 350 Display Processing Unit 360 Output terminal section 370 Storage section 371 θ-φ Coordinate Transformation Table 380 Beam Response Processing Unit 400 display device

Claims

1. A signal direction display processing device that performs processing to display the horizontal direction and elevation angle from which a target signal emitted by a target arrives, An interpolation processing unit performs a conversion process to two-dimensional data in a conical coordinate system based on the horizontal phase-alignment processing result of the target signal, which is represented by coordinates in a horizontal azimuth-elevation coordinate system based on the horizontal azimuth and elevation angle, A target detection processing unit performs a scan on the two-dimensional transformation data in a direction orthogonal to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal is maximized, and generates data relating to the arrival direction information of the target signal in the conical coordinate system, including the one or more signal levels at which the target signal is maximized. A coordinate transformation processing unit that converts the arrival direction information of the target signal in the conical coordinate system to the arrival direction information of the target signal in the horizontal azimuth-elevation coordinate system, A display processing unit generates display data that plots one or more of the signal levels at the corresponding horizontal azimuth and elevation angles based on the arrival direction information in the aforementioned horizontal azimuth-elevation coordinate system and displays them on a display device. A signal direction display processing device equipped with the following:

2. The interpolation processing unit is A processing unit that rearranges the results of the horizontal phase adjustment process to generate rearranged data, A coordinate transformation source calculation processing unit calculates the coordinates in the horizontal azimuth-elevation coordinate system corresponding to the two-dimensional transformation data of the conical coordinate system, Based on the sorted data, a transformation processing unit performs interpolation processing to calculate the signal level at the coordinates calculated by the coordinate transformation source calculation processing unit. A signal orientation display processing device according to claim 1, having the following features.

3. A signal direction display processing device that performs processing to display the horizontal direction and elevation angle from which the target signal arrives, based on a signal received by a receiver array from a target signal emitted by the target, A storage unit stores data showing the relationship between the horizontal azimuth at which the signal level obtained for each elevation angle of the beam response calculated based on the received signal is maximum, and the signal level, as a θ-φ coordinate transformation table. A beam response processing unit that, based on the θ-φ coordinate transformation table, determines the signal level at the horizontal azimuth corresponding to the horizontal phase correction result of the target signal expressed in the horizontal azimuth-elevation coordinate system, and generates two-dimensional data representing the relationship between the horizontal azimuth and the signal level. A target detection processing unit extracts the maximum value of the signal level at each elevation angle for each horizontal direction from the two-dimensional data, scans the maximum value of the signal level at each elevation angle in the horizontal direction to calculate one or more horizontal directions in which the maximum value of the signal level is maximized, and generates data relating to the direction of arrival information of the target signal, including the signal level and the horizontal direction in which the maximum value of the signal level is maximized. A display processing unit generates display data that plots one or more of the signal levels at the corresponding horizontal azimuth and elevation angle positions and displays them on a display device, based on the aforementioned arrival direction information. A signal direction display processing device equipped with the following:

4. The signal direction display processing device according to claim 3, wherein the target detection processing unit performs a maximum value processing on the two-dimensional data to calculate the maximum level in the direction of the elevation angle for each horizontal direction and a maximum value processing to calculate a maximum level that is the maximum value of the maximum level, thereby generating data relating to the direction of arrival information and the signal level of the target signal.

5. A receiver array having multiple receivers and outputting a received signal related to wave reception, A signal processing device that performs phase adjustment processing on the target signal emitted by the target based on the received signal, A signal orientation display processing device according to claim 1 or claim 3, A display device that displays information based on a display signal that includes display data generated by the signal orientation display processing device. A signal processing system having the following features.

6. A signal bearing display processing method that performs processing to display the horizontal bearing and elevation angle from which a target signal emitted by a target arrives, An interpolation process is performed to convert the target signal, which is represented by coordinates in a horizontal azimuth-elevation coordinate system based on the horizontal azimuth and elevation angle, into two-dimensional converted data in a conical coordinate system, based on the horizontal phase adjustment result of the target signal. A target detection processing step involves scanning the two-dimensional transformed data in a direction perpendicular to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal is maximized, and generating data relating to the direction of arrival information of the target signal in the conical coordinate system, including the one or more signal levels at which the target signal is maximized. A coordinate transformation process that converts the arrival direction information of the target signal in the conical coordinate system to the arrival direction information of the target signal in the horizontal azimuth-elevation coordinate system, A display processing step that generates display data for plotting one or more of the signal levels at the corresponding horizontal azimuth and elevation angles based on the arrival direction information in the aforementioned horizontal azimuth-elevation coordinate system and displaying them on a display device. A signal direction indication processing method having the following characteristics.

7. A signal direction display processing method that performs processing to display the horizontal direction and elevation angle from which the target signal is arriving, based on a signal received by a receiver array from a target signal emitted by the target, A beam response processing step that calculates the beam response based on the received signal, determines the horizontal direction at which the signal level is maximum for each elevation angle of the beam response, determines the signal level at the horizontal direction corresponding to the horizontal phase shaping result of the target signal expressed in coordinates of the horizontal direction-elevation coordinate system based on a θ-φ coordinate transformation table that stores data showing the relationship between the horizontal direction and the signal level, and generates two-dimensional data representing the relationship between the horizontal direction and the signal level. A target detection processing step involves extracting the maximum value of the signal level at each elevation angle for each horizontal direction from the two-dimensional data, scanning the maximum value of the signal level at each elevation angle in the horizontal direction to calculate one or more horizontal directions in which the maximum value of the signal level is maximized, and generating data relating to the arrival direction information of the target signal, which includes the signal level in which the maximum value of the signal level is maximized. A display processing step that generates display data to plot one or more of the signal levels at the corresponding horizontal azimuth and elevation angle positions and display them on a display device, based on the aforementioned direction of arrival information. A signal direction indication processing method having the following characteristics.

8. A program for a signal bearing display processing method that performs processing to display the horizontal bearing and elevation angle from which a target signal emitted by a target arrives, An interpolation process is performed to convert the target signal, which is represented by coordinates in a horizontal azimuth-elevation coordinate system based on the horizontal azimuth and elevation angle, into two-dimensional converted data in a conical coordinate system, based on the horizontal phase adjustment result of the target signal. A target detection processing step involves scanning the two-dimensional transformed data in a direction perpendicular to the central axis of the conical coordinate system to calculate one or more signal levels at which the target signal is maximized, and generating data relating to the direction of arrival information of the target signal in the conical coordinate system, including the one or more signal levels at which the target signal is maximized. A coordinate transformation process that converts the arrival direction information of the target signal in the conical coordinate system to the arrival direction information of the target signal in the horizontal azimuth-elevation coordinate system, A display processing step that generates display data for plotting one or more of the signal levels at the corresponding horizontal azimuth and elevation angles based on the arrival direction information in the aforementioned horizontal azimuth-elevation coordinate system and displaying them on a display device. A program for a signal direction display processing method that is performed by a computer.

9. A program for a signal direction display processing method that performs processing to display the horizontal direction and elevation angle from which the target signal is arriving, based on a signal received by a receiver array from a target, the target signal emitted by the target, A beam response processing step that calculates the beam response based on the received signal, determines the horizontal direction at which the signal level is maximum for each elevation angle of the beam response, determines the signal level at the horizontal direction corresponding to the horizontal phase shaping result of the target signal expressed in coordinates of the horizontal direction-elevation coordinate system based on a θ-φ coordinate transformation table that stores data showing the relationship between the horizontal direction and the signal level, and generates two-dimensional data representing the relationship between the horizontal direction and the signal level. A target detection processing step involves extracting the maximum value of the signal level at each elevation angle for each horizontal direction from the two-dimensional data, scanning the maximum value of the signal level at each elevation angle in the horizontal direction to calculate one or more horizontal directions in which the maximum value of the signal level is maximized, and generating data relating to the arrival direction information of the target signal, which includes the signal level in which the maximum value of the signal level is maximized. A display processing step that generates display data to plot one or more of the signal levels at the corresponding horizontal azimuth and elevation angle positions and display them on a display device, based on the aforementioned direction of arrival information. A program for a signal direction display processing method that is performed by a computer.

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