JPWO2017179342A1 - Signal processing apparatus, radar apparatus, and signal processing method - Google Patents

Abstract

A signal processing device, a radar device, and a signal processing method having a configuration for more reliably evaluating whether or not wave information is reliable. A signal processing device (20) acquires wave number data (D1) including a relationship between a wave number and a frequency based on observation data obtained by observing waves in a predetermined area around the ship. A frequency analysis unit (13), a wave information acquisition unit (14) for detecting wave data (D2) included in the wave number data (D1) by applying a predetermined filter process to the wave number data (D1), A reliability evaluation unit (9) that evaluates the reliability of the wave information specified by the wave data (D2) for a predetermined analysis region that is a part of the region;

Description

  The present invention relates to a signal processing apparatus that processes echoes from waves to calculate wave information such as wave direction, a radar apparatus including the signal processing apparatus, and a signal processing method.

  Conventionally, a wave observation radar (that is, a radar device) disclosed in Patent Document 1 is known as a device for obtaining wave information as information about waves. In this radar apparatus, referring to FIG. 2 of Patent Document 1, an echo signal obtained from an echo from a predetermined range at sea is subjected to a two-dimensional FFT process, thereby referring to FIG. 3 of Patent Document 1. A two-dimensional Fourier transform signal Sf is derived. In this radar apparatus, wave information (wave direction, wavelength, etc.) is calculated based on the two-dimensional Fourier transform signal Sf.

JP-A-3-262990

  By the way, it may be difficult for the user to determine whether or not the wave information indicated to the user from the wave observation radar accurately indicates the actual wave state. That is, it may be difficult for a user or the like to determine the reliability of wave information.

  The present invention has been made in view of the above problems, and one of its purposes is a signal processing device, a radar device, and a signal having a configuration for more reliably evaluating whether or not wave information can be trusted. It is to provide a processing method.

  In order to solve the above-described problem, a signal processing device according to an aspect of the present invention is based on observation data obtained by observing waves in a predetermined observation area, and obtains wave number data including a relationship between a wave number and a frequency. About a wave number data acquisition unit to be acquired, a wave information acquisition unit that detects wave data included in the wave number data by applying a predetermined filter process to the wave number data, and a predetermined analysis region that is a part of the observation area A reliability evaluation unit that evaluates the reliability of the wave information specified by the wave data.

  In order to solve the above problem, a signal processing method according to an aspect of the present invention provides a wave number including a relationship between a wave number and a frequency based on observation data obtained by observing waves in a predetermined observation area. Data is acquired, wave data included in the wave number data is detected by applying a predetermined filter process to the wave number data, and a predetermined analysis region that is a part of the observation area is specified by the wave data Evaluate the reliability of wave information.

  ADVANTAGE OF THE INVENTION According to this invention, the structure for evaluating more reliably whether wave information can be trusted is realizable.

It is a block diagram which shows the typical structure of the signal processing apparatus of the radar apparatus which concerns on embodiment of this invention. It is a block diagram which shows the typical structure of a radar apparatus. It is a block diagram which shows the typical structure of the 1st reliability evaluation unit of a signal processing apparatus. It is a block diagram which shows the typical structure of the 2nd reliability evaluation unit of the signal processing apparatus with which a radar apparatus is equipped. It is a typical top view on the sea which shows an example of the wave around the own ship. It is a graph which shows the result of 3DFFT processing of echo data. It is a graph which shows the processing result of a frequency analysis part. It is a figure which shows an example of the omega-theta spectrum produced | generated by the omega-theta conversion part. It is a schematic diagram which shows an example of a wave spectrum. It is a conceptual diagram for demonstrating a 1st evaluation area. It is a schematic diagram which shows the state by which the 1st evaluation area in a omega-theta spectrum was substituted. It is a key map for explaining the 2nd evaluation area. It is a figure which shows an example of the display screen of a display. It is a flowchart for demonstrating an example of the flow of a process in a signal processing apparatus. It is a flowchart for demonstrating an example of the flow of a process in the reliability evaluation part of a signal processing apparatus. It is a figure which shows an example of the display screen of the indicator of the radar apparatus which concerns on a modification.

  Hereinafter, embodiments of a signal processing device according to the present invention and a radar device including the signal processing device will be described with reference to the drawings. The present invention can be widely applied to a signal processing device for processing wave information, a radar device including the signal processing device, and a signal processing method for processing wave information.

  FIG. 1 is a block diagram showing a schematic configuration of a signal processing device 20 of a radar device 1 according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a schematic configuration of the radar apparatus 1. FIG. 3 is a block diagram showing a schematic configuration of the first reliability evaluation unit 21 of the signal processing device 20. FIG. 4 is a block diagram showing a schematic configuration of the second reliability evaluation unit 22 of the signal processing device 20 provided in the radar device 1.

  With reference to FIG. 2, the radar apparatus 1 according to the present embodiment, based on echoes that are transmitted from a transmitted wave reflected on the wave, wave information (specifically, wave direction). Etc.). The radar apparatus 1 according to the present embodiment is provided in a ship such as a fishing boat. The radar apparatus 1 may be configured to detect a ship existing around the ship.

  The radar device 1 includes an antenna unit 2, a signal processing device 20, and a display 3.

  The antenna unit 2 includes an antenna 4 that functions as both a transmitter and a receiver, a receiver 5, and an A / D converter 6.

  The antenna 4 is a radar antenna capable of transmitting a pulsed radio wave as a highly directional transmission wave. The antenna 4 is configured to receive a reflected wave (that is, an echo) that is returned when the pulsed radio wave transmitted from the antenna 4 is reflected by a target (in the case of this embodiment, a wave). ing. The radar apparatus 1 measures the time from when a pulsed radio wave is transmitted until the reflected wave is received. Thereby, the radar apparatus 1 can detect the distance r to the target. The antenna 4 is configured to be able to rotate 360 ° on a horizontal plane. The antenna 4 is configured to repeatedly transmit and receive radio waves while changing the transmission direction of pulsed radio waves (for example, changing the antenna angle). With the above configuration, the radar apparatus 1 can detect a target on a plane around the ship over 360 °.

  In the following description, the operation from the transmission of a pulsed radio wave to the transmission of the next pulsed radio wave is referred to as “sweep”. The operation of rotating the antenna 360 ° while transmitting / receiving radio waves is called “scan”.

  The receiving unit 5 detects and amplifies an echo signal obtained from an echo received by the antenna 4. The receiving unit 5 outputs the amplified echo signal to the A / D conversion unit 6. The A / D converter 6 samples an analog echo signal and converts it into digital data consisting of a plurality of bits. This digital data is echo data. The echo data includes data for specifying the intensity of the echo signal obtained from the reflected wave received by the antenna 4. The A / D converter 6 outputs the echo data to the signal processing device 20.

  With reference to FIG. 1, the signal processing device 20 includes a frequency domain spectrum generation unit 8, a reliability evaluation unit 9, and a display data generation unit 10.

  The signal processing device 20 is configured by devices such as a hardware processor 7 (for example, a CPU, FPGA, etc.) and a nonvolatile memory. For example, when the CPU reads out and executes a program from the nonvolatile memory, the signal processing device 20 can function as the frequency domain spectrum generation unit 8, the reliability evaluation unit 9, and the display data generation unit 10. .

  The signal processing device 20 processes the echo received by the antenna 4.

  FIG. 5 is a schematic plan view on the sea showing an example of waves around the ship 100. FIG. 5 shows a state in which there are two types of waves 101 and 102 toward the ship 100 around the ship 100. In FIG. 5, for example, the wave 101 in front of the starboard side of the ship 100 is the strongest wave around the ship 100. FIG. 5 shows a state where the wave 102 behind the starboard side of the ship 100 is the next strongest wave after the wave 101. In FIG. 5, a clear wavy line w is displayed for the waves 101 and 102. In addition to the waves 101 and 102, there are waves having a relatively low wave height around the ship 100, but the illustration of these waves is omitted.

  Referring to FIGS. 1 and 5, the frequency domain spectrum generation unit 8 is obtained from the waves included in the predetermined analysis region Z <b> 10 in the ship surrounding region Z <b> 1 as the predetermined observation area around the ship 100. Frequency analysis of echo. The own ship surrounding area Z <b> 1 is an area that can be detected by the radar device 1. The frequency domain spectrum generation unit 8 generates a directional frequency spectrum (frequency domain spectrum) in the analysis region Z10. In the present embodiment, as shown in FIG. 5, the analysis region Z10 is set in front of the starboard of the ship.

  The frequency domain spectrum generation unit 8 includes a data storage unit 12, a frequency analysis unit 13, a wave information acquisition unit 14, a dispersion relation calculation unit 15, an MTF processing unit 16, a ωθ conversion unit 17, and a two-dimensional spectrum conversion. Part 18.

  The data accumulating unit 12 accumulates echo data included in the ship surrounding area Z1. The data storage unit 12 extracts the echo data included in the echo image in the analysis area Z10 in the ship surrounding area Z1 obtained by one scan for each scan. As a result, the data storage unit 12 stores echo data for a plurality of scans (for example, 32 sheets) for the analysis region Z10.

  The frequency analysis unit 13 is an example of the “wave number data acquisition unit” in the present invention. The frequency analysis unit 13 acquires wave number data D1 including the relationship between the wave number and the frequency at the wave number based on the observation data (that is, echo data) obtained by observing the waves in the analysis region Z10.

  In the present embodiment, the frequency analysis unit 13 performs frequency analysis on the analysis region Z10 using echo data for a plurality of scans. Specifically, the frequency analysis unit 13 performs three-dimensional fast Fourier transform (3DFFT) processing on the analysis region Z10 using echo data for a plurality of scans. As a result, as shown in FIG. 6, wave number data D1, which is three-dimensional data in which the x-axis and y-axis units are rad / m and the z-axis unit is rad / sec, is generated for the analysis region Z10.

  FIG. 6 is a graph showing the result of 3DFFT processing of echo data. In the graph showing the processing result of the three-dimensional wave number data D1, the x axis is, for example, the wave number kx in the east-west direction, the y axis is the wave number ky in the north-south direction, and the z axis is the angular frequency ω. In the wave number data D1 for specifying the three-dimensional graph, the result indicating the same echo appears symmetrically in the positive direction and the negative direction of the frequency.

  With reference to FIG. 1, the frequency analysis unit 13 outputs the obtained three-dimensional wave number data D1 to the wave information acquisition unit 14 and the reliability evaluation unit 9. The wave information acquisition unit 14 is an example of the “wave information acquisition unit” in the present invention. The wave information acquisition unit 14 acquires the wave data D2 by extracting the wave component that is a component caused by the wave from the three-dimensional wave number data D1 obtained by the frequency analysis unit 13. Specifically, the wave information acquisition unit 14 performs a filtering process using the wave dispersion relation calculated by the dispersion relation calculation unit 15 on the three-dimensional wave number data D1. Thereby, the wave information acquisition part 14 detects a wave component, ie, the wave component data contained in the wave number data D1. The dispersion relation calculation unit 15 is provided as a part for calculating the dispersion relation regarding the wave component. For example, the dispersion relation calculation unit 15 calculates a dispersion relation expression represented by the following expression (1).

ω ² = gk (1)

  Where ω is an angular frequency, k is a wave number, and g is a gravitational acceleration. The calculation result of the dispersion relational expression is a content indicating a gravitational wave.

  The wave information acquisition unit 14 extracts a wave component by performing a filter process of extracting spectrum data close to the above equation (1) from the three-dimensional data obtained by the frequency analysis unit 13. Thereby, the frequency analysis part 13 produces | generates the wave data which are the two-dimensional spectrum data shown in FIG. FIG. 7 is a graph showing the processing result of the frequency analysis unit 13. The x-axis and y-axis in this two-dimensional data are the same as the dimensions of the three-dimensional data in FIG.

  The kxky spectrum shown as an example in FIG. 7 has the spectrum intensity of the sample points constituting each point of the coordinates as information. In each of the drawings from FIG. 7 to FIG. 12, which will be described later, the spectrum intensity of each sample point is shown corresponding to the hatching density. In other words, the echo intensity of the sample points that constitute the dark hatched portion is higher than the echo intensity of the sample points that constitute the thin hatched portion. The wave information acquisition unit 14 outputs the wave data D2 specifying the wave component to the reliability evaluation unit 9 and the MTF processing unit 16.

  The MTF processing unit 16 generates wave data D3 by multiplying a predetermined coefficient corresponding to the wave number k by a value specified by the wave data D2.

  The ωθ conversion unit 17 generates a ωθ spectrum by converting the spectrum specified by the wave data D3 extracted by the wave information acquisition unit 14 and multiplied by the coefficient by the MTF processing unit 16 into polar coordinates (ωθ coordinates). . In this ωθ coordinate, the horizontal axis corresponds to the wave direction θ (azimuth direction) with respect to the ship 100 and the vertical axis corresponds to the angular frequency ω. The ωθ spectrum is a two-dimensional spectrum in the azimuth direction θ and the frequency direction ω in the polar coordinates of the spectrum specified by the wave data D3. This ωθ spectrum includes an azimuth spectrum as a spectral component in the azimuth direction θ and a frequency spectrum as a spectral component in the frequency direction ω. Note that the ωθ spectrum may be subjected to a smoothing process.

  FIG. 8 is a diagram illustrating an example of the ωθ spectrum generated by the ωθ conversion unit 17. With reference to FIG. 1, FIG. 5, and FIG. 8, the ωθ spectrum shown as an example has spectral intensities of sample points constituting each point of polar coordinates as information. In FIG. 8, as an example, a first peak region 31 corresponding to the wave 101 included in the analysis region Z10 and a second peak region 32 corresponding to the wave 102 included in the analysis region Z10 are shown. In the present embodiment, the peak value P1 of the spectrum in the first peak region 31 is larger than the peak value P2 of the spectrum in the second peak region 32.

  The ωθ conversion unit 17 outputs ωθ spectrum data D4 as data specifying the ωθ spectrum to the two-dimensional spectrum conversion unit 18 and the reliability evaluation unit 9.

  The two-dimensional spectrum conversion unit 18 generates wave spectrum data D5 as data specifying the wave spectrum shown in FIG. 9 by converting the ωθ spectrum into xy orthogonal coordinates. FIG. 9 is a schematic diagram illustrating an example of a wave spectrum. In this orthogonal coordinate, the x axis indicates, for example, the east-west direction, and the y axis indicates, for example, the north-south direction.

  In the ωx−ωy orthogonal coordinates, the direction from the origin indicates the wave direction. Moreover, the distance of the wave spectrum from the origin indicates the wave period. In addition, the spectrum intensity of each sample point is shown in correspondence with the hatching density. This wave spectrum shows a state in which the largest wave 101 exists in the analysis region Z10 and the second largest wave 102 exists in the analysis region Z10. The two-dimensional spectrum conversion unit 18 outputs the wave spectrum data D5 to the display data generation unit 10.

  Next, the configuration of the reliability evaluation unit 9 will be described more specifically. 1, 3, and 4, the reliability evaluation unit 9 determines whether or not the wave information specified by the wave spectrum indicates the actual wave state (in other words, the wave information). It is provided to evaluate the reliability of information.

  The reliability evaluation unit 9 includes a first reliability evaluation unit 21 and a second reliability evaluation unit 22.

  The first reliability evaluation unit 21 includes a pre-filter power calculation unit 23, a post-filter power calculation unit 24, a power ratio calculation unit 25, and an index determination unit 26.

  The pre-filter power calculation unit 23 calculates the power of each of the three-dimensional components specified by the three-dimensional data (that is, wave number data D1) generated by the frequency analysis unit 13 as pre-filter power PW1. Specifically, the sum of all elements in the array (three-dimensional array) at the three-dimensional coordinates specified by the three-dimensional data is calculated as the pre-filter power PW1. The “element” of all elements in the three-dimensional array means echo intensity at each wave number and frequency. The pre-filter power calculation unit 23 outputs the calculated value of the pre-filter power PW1 to the power ratio calculation unit 25.

  The filtered power calculation unit 24 calculates the power of each two-dimensional component specified by the wave data D2 as the filtered power PW2. Specifically, all of the wave component data (two-dimensional array), which is two-dimensional data after the dispersion relation filtering (in other words, the component on the gravitational wave curved surface is extracted) in the wave information acquisition unit 14. A value obtained by doubling the sum of the elements is calculated as filtered power PW2. The “element” of all elements in the two-dimensional array means echo intensity at each wave number.

  The reason for doubling the sum of all elements in the wave component data (two-dimensional array) is that the dispersion relationship only looks at the positive direction of the positive and negative frequencies. This is because it needs to be doubled. The post-filter power calculation unit 24 outputs the calculated post-filter power PW2 value to the power ratio calculation unit 25.

  The power ratio calculation unit 25 calculates a ratio PW2 / PW1 between the post-filter power PW2 and the pre-filter power PW1, and outputs the calculated power ratio PW2 / PW1 to the power ratio index determination unit 26.

  The power ratio index determination unit 26 determines whether or not the power ratio PW2 / PW1 is equal to or greater than a predetermined threshold value Pwth. The threshold value Pwth is set to a predetermined value. The power ratio PW2 / PW1 increases as the number of wave components included in the echo data increases. On the other hand, if the component other than the wave component (for example, the component due to the echo from the land) is large in the echo data, the power ratio PW2 / PW1 is small.

  That is, the larger the power ratio PW2 / PW1, the more wave components are included in the echo data, and the echo data can be said to be data that more accurately indicates actual waves. If the power ratio PW2 / PW1 is equal to or greater than the threshold value Pwth, the power ratio index determination unit 26 determines that the reliability of the echo data is high. On the other hand, if the power ratio PW2 / PW1 is less than the threshold value Pwth, the power ratio index determination unit 26 determines that the reliability of the echo data is low. The power ratio index determination unit 26 outputs power ratio determination result data D6 as data indicating the determination result to the two-dimensional spectrum conversion unit 18.

  Next, the configuration of the second reliability evaluation unit 22 will be described more specifically.

  With reference to FIG. 1, FIG. 4, FIG. 5 and FIG. 8, the reliability evaluation unit 9 sets the wave information specified by the wave data D3 for the first evaluation area AR10 and the second evaluation area AR20 described later. Evaluate reliability.

  The reliability evaluation unit 9 includes a first evaluation spectrum calculation unit 41, a second evaluation spectrum calculation unit 42, a first spectrum evaluation unit 43, a second spectrum evaluation unit 44, a peak ratio calculation unit 45, And a peak ratio evaluation unit 46.

  The first evaluation spectrum calculation unit 41 relates to the first evaluation area AR10 as a region including the region having the maximum peak value in the ωθ spectrum, based on the wave data D2, and is a first evaluation spectrum that is a wave-related spectrum. The calculation process of SP10 is performed.

  The first evaluation spectrum calculation unit 41 includes a first peak detection unit 47, a first evaluation area setting unit 48, and a first evaluation spectrum extraction unit 49.

  The first peak detector 47 detects a first peak point PT1 as a point having the highest peak value (echo intensity) in the ωθ spectrum obtained from the echo image included in the analysis region Z10. The ωθ spectrum is calculated based on the echo obtained from the waves included in the analysis region Z10, and the wave echoes at each position of the ωθ coordinate specified by the wave angular frequency and the wave arrival direction. It can be said that it is a ωθ spectrum in which the intensity is displayed. In the present embodiment, for example, the first peak detector 47 detects the darkest point in FIG. 8, that is, the first peak point P1 as the point having the peak value P1.

  FIG. 10 is a conceptual diagram for describing the first evaluation area AR10. Referring to FIGS. 4 and 10, first evaluation area setting unit 48 sets a first evaluation area AR10. The first evaluation area setting unit 48 sets a predetermined first evaluation area AR10 including the first peak point PT1. The first evaluation area AR10 is set over a predetermined range in each of the azimuth direction θ and the frequency direction ω with the first peak point PT1 as the center. In the present specification, the first evaluation area AR10 and the second evaluation area AR20 are exaggerated in the azimuth direction θ and the frequency direction ω.

  When the first peak point PT1 exists near θ = 0 deg or near 360 deg, the first evaluation area setting unit 48 has a portion of θ = 0 deg and a portion of θ = 360 deg of the ωθ spectrum continuous. By treating as being, it is possible to suppress the generation of the unnatural first evaluation area AR10 in which the peak value changes discontinuously. Similarly, in the frequency direction ω, when the first peak point PT1 is present at the lower limit (for example, 0 rad / s) or near the upper limit, the first evaluation area setting unit 48 includes, in the frequency direction ω, of the ωθ spectrum. For the region outside the ωθ spectrum, a spectrum having the same intensity as the minimum signal intensity in the ωθ spectrum is complemented. Thereby, generation | occurrence | production of the unnatural 1st area AR10 for evaluation in which a peak value changes discontinuously can be suppressed.

  The first evaluation spectrum extraction unit 49 extracts the first evaluation spectrum SP10. The first evaluation spectrum SP10 is a spectrum used for evaluating reliability as to whether or not the wave information specified by the spectrum in the first evaluation area AR10 accurately indicates the actual wave state. . The first evaluation spectrum SP10 is a spectrum having the largest peak value P1 in the first evaluation area AR10.

  The components of the first evaluation spectrum SP10 extracted by the first evaluation spectrum extraction unit 49 include a first azimuth spectrum SP11 and a first frequency spectrum SP12. The first azimuth spectrum SP11 indicates a spectrum of intensity along the azimuth direction θ in the first evaluation area AR10. There are two types of methods for extracting the first orientation spectrum SP11. More specifically, (1) the integration method and (2) the center extraction method can be exemplified.

  In the integration method of (1) above, an integral value obtained by integrating the intensity of the spectrum having the same coordinate in the azimuth direction θ in the frequency direction ω at any one point in the azimuth direction θ is the first azimuth spectrum SP1 at the one point. It becomes strength. And the 1st azimuth | direction spectrum SP11 can be extracted by performing the process which plots this integrated value along the azimuth | direction direction (theta). In addition, in FIG. 10, 1st azimuth | direction spectrum SP11 extracted by this integration method is shown as an example.

  In the center extraction method of (2) above, in the ωθ spectrum, a spectrum (that is, a one-dimensional array) showing the relationship between the azimuth θ and the intensity on the reference line L1 passing through the first peak point PT1 and extending in the azimuth direction θ. Spectrum) is extracted as the first orientation spectrum SP11.

  The first frequency spectrum SP12 indicates a spectrum of intensity along the frequency direction ω in the first evaluation area AR10. As the extraction method of the first frequency spectrum SP12, the above two types can be exemplified.

  In the integration method of (1) above, the integral value obtained by integrating the intensity of the spectrum having the same coordinate in the frequency direction ω in the azimuth direction θ at any one point in the frequency direction ω is the first frequency spectrum SP12 at the one point. It becomes strength. And the 1st frequency spectrum SP12 can be extracted by performing the process which plots this integrated value along the frequency direction (omega). In addition, in FIG. 10, 1st frequency spectrum SP12 extracted by this integration method is shown as an example.

  In the center extraction method of (2) above, in the ωθ spectrum, a spectrum indicating the relationship between the frequency ω and the intensity on the reference line L2 passing through the first peak point PT1 and extending in the frequency direction ω (that is, a one-dimensional array). Spectrum) is extracted as the first frequency spectrum SP12.

  Referring to FIGS. 4 and 8, the second evaluation spectrum calculation unit 42 determines the areas other than the first evaluation area AR10 in the evaluation target area AR1 that is an area included in the ωθ coordinates shown in FIG. With respect to the second evaluation area AR20 as a region including the region having the largest peak value (echo intensity) in the ωθ spectrum, the calculation processing of the second evaluation spectrum SP20 that is a spectrum related to waves is performed based on the wave data D2.

  The second evaluation spectrum calculation unit 42 includes a first evaluation area replacement unit 56, a second peak detection unit 57, a second evaluation area setting unit 58, and a second evaluation spectrum extraction unit 59. doing.

  The first evaluation area replacement unit 56 performs a process of reducing the strength of the first evaluation spectrum SP10 in each coordinate of the first evaluation area AR10 in the ωθ spectrum (that is, a replacement process). Specifically, the first evaluation area replacement unit 56 replaces the signal intensity at each coordinate of the first evaluation area AR10 in the ωθ spectrum with the minimum intensity or zero in the ωθ spectrum. As a result, as shown in FIG. 11, the signal intensity of the first evaluation area AR10 including the first peak point PT1 becomes a small value about noise. FIG. 11 is a schematic diagram showing a state in which the first evaluation area AR10 in the ωθ spectrum has been subjected to replacement processing.

  Referring to FIGS. 4 and 8 again, the second peak detector 57 has the highest peak value (echo intensity) in the ωθ spectrum in the area excluding the first evaluation area AR10 in the evaluation target area AR1. A second peak point PT2 as a high point is extracted. In the present embodiment, the second peak detector 57 detects, for example, the darkest point in the ωθ spectrum in FIG.

  FIG. 12 is a conceptual diagram for explaining the second evaluation area AR20. Referring to FIGS. 4 and 12, second evaluation area setting unit 58 sets a predetermined second evaluation area AR20 including second peak point PT2 in the ωθ spectrum shown in FIG. The setting method of the second evaluation area AR20 by the second evaluation area setting unit 58 is the same as the setting method of the first evaluation area AR10 by the first evaluation area setting unit 48.

  Specifically, the second evaluation area AR20 is centered on the second peak point PT2 where the strongest echo intensity is observed in the area excluding the first evaluation area AR10 in the evaluation target area AR1, and the azimuth direction θ And the frequency range ω are set over a predetermined range.

  As described above, the ωθ spectrum used for setting the second evaluation area AR20 is the ωθ spectrum before the first evaluation area AR10 is replaced, and is the ωθ spectrum shown in FIG. When the second evaluation area AR20 is set based on the ωθ spectrum (ωθ spectrum shown in FIG. 11) after the first evaluation area AR10 is replaced, the first evaluation area AR10 and the second evaluation area AR10 It is conceivable that an unnatural edge occurs in the overlapping portion with the evaluation area. Therefore, the ωθ spectrum used for setting the second evaluation area AR20 is the ωθ spectrum (ωθ spectrum shown in FIG. 8) before the first evaluation area AR10 is replaced. Edge can be suppressed.

  In addition, when the second peak point PT2 is in the vicinity of θ = 0 deg or at θ = 360 deg, the second evaluation area setting unit 58 has the θ = 0 deg portion and the θ = 360 deg portion of the ωθ spectrum continuous. By handling that the peak value is discontinuously changed, it is possible to suppress the generation of the unnatural second evaluation area AR20. Similarly, in the frequency direction ω, when the second peak point PT2 is present at the lower limit (for example, 0 rad / s) or near the upper limit, the second evaluation area setting unit 58 includes, in the frequency direction ω, of the ωθ spectrum. For the region outside the ωθ spectrum, a spectrum having the same intensity as the minimum signal intensity in the ωθ spectrum is complemented. Thereby, generation | occurrence | production of the unnatural 2nd area AR20 for evaluation in which a peak value changes discontinuously can be suppressed.

  The second evaluation spectrum extraction unit 59 extracts the second evaluation spectrum SP20. The second evaluation spectrum SP20 is a spectrum used for evaluating reliability as to whether or not the wave information specified by the spectrum in the second evaluation area AR20 accurately indicates the actual wave state. . The second evaluation spectrum SP20 is a spectrum having the largest peak value P2 in the center of the second evaluation area AR20.

  The components of the second evaluation spectrum SP20 extracted by the second evaluation spectrum extraction unit 59 include a second azimuth spectrum SP21 and a second frequency spectrum SP22. The second azimuth spectrum SP21 indicates a spectrum of intensity along the azimuth direction θ in the second evaluation area AR20. There are two types of methods for extracting the second orientation spectrum SP21. More specifically, the above-described (1) integration method and (2) center extraction method can be exemplified.

  Therefore, detailed description of the integration method and the center extraction method for the second evaluation spectrum SP20 will be omitted. In addition, in FIG. 12, 2nd direction spectrum SP21 extracted by the integration method is shown as an example.

  The second frequency spectrum SP22 indicates a spectrum of intensity along the frequency direction ω in the second evaluation area AR20. As the extraction method of the second frequency spectrum SP22, the above two types can be exemplified. In addition, in FIG. 12, 2nd frequency spectrum SP22 extracted by the integration method is shown as an example.

  Referring to FIGS. 4 and 10, first spectrum evaluation unit 43 determines whether or not the wave information specified in first evaluation area AR10 in the ωθ spectrum generated by the frequency analysis indicates an actual wave state. The reliability is determined using the first evaluation spectrum SP10.

  Specifically, the first spectrum evaluation unit 43 calculates average intensity values PA11 and PA12 for each of the first orientation spectrum SP11 and the first frequency spectrum SP12. Then, the first spectrum evaluation unit 43 calculates a value P11 / PA11 obtained by dividing the central peak value P11 as the reference value of the first orientation spectrum SP11 by the average value PA11 as the reliability determination index B11. Similarly, the first spectrum evaluation unit 43 calculates a value P12 / PA12 obtained by dividing the central peak value P12 of the first frequency spectrum SP12 by the average value PA12 as the reliability determination index B12. The center peak value refers to the signal intensity at the center position in the corresponding azimuth direction θ or frequency direction ω.

  The first spectrum evaluation unit 43 determines whether each reliability determination index B11, B12 is equal to or greater than a predetermined threshold value B1th. This is because, in each of the first azimuth spectrum SP11 and the first frequency spectrum SP12, if the corresponding reliability determination index B11, B12 is large, the peak shape of the spectrum is sharp, and the reliability is improved because the wave component is clear. This is because it can be determined to be high.

  The first spectrum evaluation unit 43 determines that the reliability of the wave information specified by the first evaluation spectrum SP10 is high when each of the reliability determination indexes B11 and B12 is equal to or greater than the threshold value B1th. On the other hand, the first spectrum evaluation unit 43 determines that the reliability of the wave information specified by the first evaluation spectrum SP10 is low when at least one of the reliability determination indexes B11 and B12 is less than the threshold value B1th. To do.

  4 and 12, the second spectrum evaluation unit 44 determines whether or not the wave information specified in the second evaluation area AR20 in the ωθ spectrum generated by the frequency analysis indicates an actual wave state. The reliability is determined using the second evaluation spectrum SP20. In the present embodiment, the process in the second spectrum evaluation unit 44 is the same as the process in the first spectrum evaluation unit 43.

  Specifically, the second spectrum evaluation unit 44 calculates average values PA21 and PA22 of the intensity for each of the second orientation spectrum SP21 and the second frequency spectrum SP22. Then, the second spectrum evaluation unit 44 calculates a value P21 / PA21 obtained by dividing the central peak value P21 as the reference value of the second orientation spectrum SP21 by the average value PA12 as the reliability determination index B21. Similarly, the second spectrum evaluation unit 44 calculates a value P22 / PA22 obtained by dividing the central peak value P22 of the second frequency spectrum SP22 by the average value PA22 as the reliability determination index B22.

  The second spectrum evaluation unit 44 determines whether or not each reliability determination index B21, B22 is equal to or greater than a predetermined threshold B2th (for example, 1.5). The second spectrum evaluation unit 44 determines that the reliability of the wave information specified by the second evaluation spectrum SP20 is high when each of the reliability determination indexes B21 and B22 is equal to or greater than the threshold value B2th. On the other hand, the second spectrum evaluation unit 44 determines that the reliability of the wave information specified by the second evaluation spectrum SP20 is low when at least one of the reliability determination indexes B21 and B22 is less than the threshold value B2th. To do.

  With reference to FIG. 4, FIG. 10, and FIG. 12, the peak ratio calculation unit 45 calculates the ratio between the first evaluation spectrum SP10 and the second evaluation spectrum SP20. Specifically, the peak ratio calculation unit 45 calculates a value P21 / P11 obtained by dividing the central peak value P21 of the second orientation spectrum SP21 by the central peak value P11 of the first orientation spectrum SP11 as the reliability determination index B3. . Similarly, the peak ratio calculation unit 45 calculates a value P22 / P12 obtained by dividing the central peak value P22 of the second frequency spectrum SP22 by the central peak value P12 of the first frequency spectrum SP12 as the reliability determination index B4.

  The peak ratio evaluation unit 46 determines whether or not each reliability determination index B3, B4 is equal to or greater than a predetermined threshold value B34th. Here, if the central peak values P21 and P22 of the second evaluation spectrum SP20 are sufficiently smaller than the corresponding peak values P11 and P12 of the first evaluation spectrum SP10, the waves specified by the second evaluation spectrum SP20 are Therefore, it can be considered that there is a noise level with respect to the waves specified by the first evaluation spectrum SP10, and the reliability is low or can be ignored.

  The peak ratio evaluation unit 46 determines that the reliability of the wave information specified by the second evaluation spectrum SP20 is high when each of the reliability determination indexes B3 and B4 is equal to or greater than the threshold value B34th. On the other hand, when at least one of the reliability determination indexes B3 and B4 is less than the threshold B34th, the peak ratio evaluation unit 46 determines that the reliability of the wave information specified by the second evaluation spectrum SP20 is low. .

  The data D7, D8, D9 indicating the evaluation results of the first spectrum evaluation unit 43, the second spectrum evaluation unit 44, and the peak ratio evaluation unit 46 of the reliability evaluation unit 9 are shown in FIG. Is output to the two-dimensional spectrum converter 18 shown. The two-dimensional spectrum conversion unit 18 converts the coordinates of the evaluation areas AR10 and AR20 from ωθ coordinates to ωx-ωy coordinates. The data processed by the two-dimensional spectrum conversion unit 18 is output to the display data generation unit 10. In the present embodiment, only a part of the wave information such as the wave period and the wave direction is output. Therefore, the two-dimensional spectrum conversion unit 18 is omitted, and the data D4 output from the ωθ conversion unit 17 and the data D6 to D9 output from the reliability evaluation unit 9 are directly output to the display data generation unit 10. May be. Thereby, the configuration of the signal processing device 20 can be further simplified.

  The display data generation unit 10 uses the two-dimensional wave spectrum data D5 output from the two-dimensional spectrum conversion unit 18 and the reliability evaluation data D6 to D9 for an image to be displayed on the display unit 3. Generate data.

  FIG. 13 is a diagram illustrating an example of a display screen of the display device 3. Referring to FIGS. 1, 5, and 13, display device 3 is, for example, a liquid crystal display device, and displays an image based on display data. FIG. 13 shows, as an example, a case where it is determined that the reliability of the detection result of the wave 101 is high and the reliability of the detection result of the wave 102 is low.

  For example, the display data generation unit 10 determines the strongest wave 101 in the ship surrounding area AR1 from the coordinates and signal intensity of the area corresponding to the first evaluation area AR10 out of the spectrum specified by the wave spectrum data D5. Detect wave information. The wave information in this case is, for example, the wave height, direction, and wavelength. Further, the display data generation unit 10 generates data indicating whether or not the detection result of the wave 101 has sufficient reliability based on the output result of the first spectrum evaluation unit 43.

  For example, when the wave information of the wave 101 has sufficient reliability, the display data generation unit 10 generates data that permits the wave information to be displayed for the wave 101. On the other hand, for example, when the wave information of the wave 101 does not have sufficient reliability, the display data generation unit 10 generates data that does not permit the wave information to be displayed for the wave 101.

  Similarly to the above, the display data generation unit 10 determines, for example, the own ship surrounding area AR1 from the coordinates and signal intensity of the area corresponding to the second evaluation area AR20 in the spectrum specified by the wave spectrum data D5. , Wave information of the second strongest wave 102 is detected. The wave information in this case is, for example, the wave height, direction, and wavelength. Furthermore, the display data generation unit 10 generates data indicating whether or not the wave information of the wave 102 has sufficient reliability based on the output result of the second spectrum evaluation unit 44.

  For example, when the wave information of the wave 102 has sufficient reliability, the display data generation unit 10 generates data that allows the wave information to be displayed for the wave 102. On the other hand, for example, when the wave information of the wave 102 does not have sufficient reliability, the display data generation unit 10 generates data that does not permit the wave information to be displayed for the wave 102.

  The display data generated by the above processing is output from the display data generation unit 10 to the display 3.

  For example, the display 3 can display the wave information specified by the display data for each of the waves 101 and 102. The display 3 has a first wave display area 61 and a second wave display area 62.

  When the reliability of the wave information related to the wave 101 is high, as shown in FIG. 13, the wave information related to the wave 101 (in this embodiment, wave height, direction, and wavelength) is displayed in the first wave display area 61. The On the other hand, when the reliability of the wave information related to the wave 101 is low, the wave information related to the wave 101 is not displayed in the first wave display area 61, for example, a horizontal bar is displayed.

  Similarly to the above, when the reliability of the wave information related to the wave 102 is high, the wave information related to the wave 102 (in this embodiment, wave height, direction, and wavelength) is displayed in the second wave display area 62. On the other hand, when the reliability of the wave information related to the wave 102 is low, as shown in FIG. 13, the wave information related to the wave 102 is not displayed in the second wave display area 62, for example, a horizontal bar is displayed.

  Next, an example of the flow of processing in the signal processing device 20 will be described. FIG. 14 is a flowchart for explaining an example of a processing flow in the signal processing device 20. In addition, below, when it demonstrates with reference to a flowchart, it demonstrates, referring also to figures other than a flowchart suitably.

  In the signal processing device 20, first, the data storage unit 12 stores the echo data output from the reception unit 5 for a plurality of scans (32 scans in the present embodiment) (step S11).

  Next, the frequency analysis unit 13 performs frequency analysis using echo data for a plurality of scans, thereby acquiring wave number data D1 (step S12). That is, three-dimensional wave number data including the relationship between the wave number and the frequency is acquired based on the observation data obtained by observing the waves in the analysis region Z10 in the ship surrounding area AR1 as a predetermined observation area. .

  Next, the wave information acquisition unit 14 performs a filtering process using the wave dispersion relationship calculated by the dispersion relationship calculation unit 15 on the three-dimensional wave number data D1. Thereby, the wave information acquisition part 14 detects the wave component, ie, the wave data D2 contained in the wave number data D1 (step S13).

  Next, the MTF processing unit 16 generates wave data D3 by performing a process (step S14) of multiplying the wave data D2 by a predetermined coefficient.

  Thereafter, the ωθ conversion unit 17 converts the coordinates of the wave data D3 into polar coordinates of ωθ (step S15).

  After that, the reliability evaluation unit 9 uses the wave number data D1 output from the frequency analysis unit 13, the wave data D2, and the ωθ spectrum data D4 output from the ωθ conversion unit 17, and the reliability of the wave data D3. Sex is evaluated (step S16). At this time, the reliability evaluation unit 9 uses the ωθ spectrum data D4 to identify the first evaluation area AR10 and the second evaluation area AR20, which are part of the evaluation target area AR1, using the wave data D3. Evaluate the reliability of wave information.

  The two-dimensional spectrum conversion unit 18 outputs the ωθ spectrum data D4 output from the ωθ spectrum and the reliability evaluation results of the evaluation areas AR10 and AR20 output from the reliability evaluation unit 9 (in this embodiment, evaluation data). D6 to D9) are converted into data of two-dimensional coordinates of kyky (step S17).

  Next, the display data generation unit 10 uses the ωθ spectrum data D5 output from the two-dimensional spectrum conversion unit 18 to determine the direction, wave height, and frequency of the largest wave 101 and the second largest wave 102. The data for displaying the information of the wave that passed the reliability evaluation is generated. By using this data, highly reliable wave data is displayed on the display 3.

  Next, an example of the flow of processing (step S16) in the reliability evaluation unit 9 of the signal processing device 20 will be described. FIG. 15 is a flowchart for explaining an example of the flow of processing in the reliability evaluation unit 9 of the signal processing device 20.

  In the reliability evaluation unit 9, first, the first reliability evaluation unit 21 determines power ratio reliability. The index determination unit 26 of the first reliability evaluation unit 21 determines that a sufficiently large wave component is detected in the signal processing device 20 when the power ratio PW2 / PW is equal to or greater than the threshold value Pwth. (OK in step S21), the reliability evaluation by the reliability evaluation unit 9 (steps S22 to S28) is permitted.

  On the other hand, the index determination unit 26 of the first reliability evaluation unit 21 does not detect a sufficiently large wave component in the signal processing device 20 when the power ratio PW2 / PW is less than the threshold value Pwth. (NG in step S21). In this case, the index determination unit 26 of the first reliability evaluation unit 21 outputs the data D6 indicating that the reliability of the wave information for each of the waves 101 and 102 is low to the two-dimensional spectrum conversion unit 18 (step) S23).

  When the first reliability evaluation unit 21 permits the reliability evaluation by the second reliability evaluation unit 22 (OK in step S21), the first spectrum evaluation unit 43 of the second reliability evaluation unit 22 performs the first evaluation. It is determined whether or not the service spectrum SP10 shows a reliable value (step S22).

  In at least one of the first orientation spectrum SP11 and the first frequency spectrum SP12, when the corresponding determination index B11, B12 is less than the threshold value B1th (NG in step S22), the first spectrum evaluation unit 43 performs the first evaluation. It is determined that the reliability of the wave information is low for the wave 101 in the service area AR10, that is, the strongest wave 101 in the ship surrounding area AR1 (step S23).

  In addition, when the reliability of the wave information regarding the wave 101 is low, the reliability of the wave information regarding the wave 102 is naturally considered to be low. Therefore, in this case, the first spectrum evaluation unit 43 determines that the reliability of the wave information is also low for the wave 102 specified by the second evaluation spectrum SP20 (step S23). In this case, the first spectrum evaluation unit 43 outputs data D7 indicating the determination result to the two-dimensional spectrum conversion unit 18.

  On the other hand, in any of the first azimuth spectrum SP11 and the first frequency spectrum SP12 of the first evaluation spectrum SP10, if the corresponding determination index B11, B12 is equal to or greater than the threshold value B1th (OK in step S22), the first The spectrum evaluation unit 43 determines that the reliability of the wave information is high for the wave 101 in the first evaluation area AR10, that is, the strongest wave 101 in the analysis area Z10 of the ship surrounding area AR1 (step S24). In this case, the first spectrum evaluation unit 43 outputs data D7 indicating the determination result to the two-dimensional spectrum conversion unit 18.

  Next, when it is determined that the reliability of the wave information regarding the wave 101 is high, the peak ratio evaluation unit 46 determines that the reliability determination indexes B3 and B4 for the peak ratios P21 / P11 and P22 / P12 are threshold values. It is determined whether or not B34th or more (step S25).

  When at least one of the reliability determination indexes B3 and B4 is less than the threshold value B34th (NG in step S25), the peak ratio evaluation unit 46 determines the wave information of the wave 102 specified by the second evaluation spectrum SP20. It is determined that the reliability is low (step S27). The peak ratio evaluation unit 46 outputs data D9 indicating the determination result to the two-dimensional spectrum conversion unit 18.

  On the other hand, when both of the reliability determination indexes B3 and B4 are equal to or greater than the threshold value B34th (OK in step S25), the second spectrum evaluation unit 44 evaluates the second evaluation spectrum SP20. More specifically, the second spectrum evaluation unit 44 determines whether or not the second evaluation spectrum SP20 indicates a reliable value (step S26).

  When at least one of the second azimuth spectrum SP21 and the second frequency spectrum SP22 has a corresponding determination index B21, B22 that is less than the threshold value B2th (NG in step S26), the second spectrum evaluation unit 44 uses the analysis region Z10. It is determined that the reliability of the wave information is low for the wave 102 at (step S27). Then, the second spectrum evaluation unit 44 outputs data D8 indicating the determination result to the two-dimensional spectrum conversion unit 18.

  On the other hand, in any of the second azimuth spectrum SP21 and the second frequency spectrum SP22 of the second evaluation spectrum SP20, if the corresponding determination index B21, B22 is equal to or greater than the threshold value B2th (OK in step S26), the second The spectrum evaluation unit 44 determines that the reliability of the wave information is high for the wave 102 in the analysis region A10 (second evaluation area AR20) (step S28). In this case, the second evaluation spectrum evaluation unit 44 outputs data D8 indicating the determination result to the two-dimensional spectrum conversion unit 18.

  Through the above processing flow, the display data generation unit 10 has the reliability whether the wave information about the wave 101 has reliability and the wave information about the wave 102 have reliability. Data on whether or not. The display data generation unit 10 generates data for displaying an image on the display 3 based on these data (that is, reliability data).

  As described above, according to the present embodiment, the reliability evaluation unit 9 evaluates the reliability of the wave information for the analysis region Z10 that is a part of the ship surrounding region Z1. According to this configuration, the reliability evaluation unit 9 can evaluate the reliability of the wave information by paying attention to data indicating that a relatively large wave is generated in the analysis region Z10 among the wave data. With such a configuration, the reliability evaluation unit 9 can more reliably determine whether or not the wave information can be trusted.

  In addition, according to the present embodiment, the reliability evaluation unit 9 is based on the evaluation spectrum calculation units 41 and 42 for calculating the waves SP10 and SP20 related to the waves based on the wave data and the spectra SP10 and SP20 for the analysis region Z10. Spectrum evaluation units 43 and 44 for evaluating reliability. According to this configuration, the reliability evaluation unit 9 can evaluate the reliability of the wave information using the spectra SP10 and SP20 related to the waves.

  Further, according to the present embodiment, the spectrum evaluation units 41 and 42 correspond to the average values PA11, PA12, and PA12 corresponding to the central peak values P11, P12, P21, and P22 as the intensity reference values of the corresponding spectra SP10 and SP20. , The reliability determination indexes B11, B12, B21, and B22 are calculated from the relationship with PA22. The determination indexes B11, B12, B21, and B22 are values obtained by dividing the central peak values P11, P12, P21, and P22 by the corresponding average values PA11, PA12, PA21, and PA22. Further, the spectrum evaluation units 43 and 44 evaluate the presence / absence of reliability based on whether or not the determination indexes B11, B12, B21, and B22 are equal to or higher than the corresponding predetermined threshold values B1th and B2th. According to this configuration, the reliability of the wave information can be more accurately evaluated based on the steepness (steepness degree) of the shape of each component spectrum SP11, SP12, SP21, SP22.

  Further, according to the present embodiment, the first spectrum extraction unit 49 of the reliability evaluation unit 9 extracts the first evaluation spectrum SP10 having the largest peak value in the first evaluation area AR10. Then, the first spectrum evaluation unit 43 determines the reliability of the wave information based on the first evaluation spectrum SP10. According to this configuration, the reliability evaluation unit 9 can evaluate the reliability of the wave information using the spectrum for which the spectrum shape relating to the wave in the analysis region Z10 is most clearly evaluated.

  In addition, according to the present embodiment, the second spectrum extraction unit 59 of the reliability evaluation unit 9 determines the location where the strongest echo intensity is observed in the area excluding the first evaluation area AR10 in the evaluation target area AR1. The second evaluation spectrum SP20 that is the second evaluation area AR20 and includes the peak value P2 is extracted. Then, the second spectrum evaluation unit 44 determines the reliability of the wave information based on the second evaluation spectrum SP20. According to this configuration, the reliability evaluation unit 9 adds the spectrum shape related to the waves in the ship surrounding area AR1 to 2 in addition to the first evaluation spectrum SP10 that most easily evaluates the spectrum shape related to the waves in the analysis area Z10. The reliability of the wave information can be evaluated using the second evaluation spectrum SP20 that is the second most easily evaluated.

  Further, according to the present embodiment, the second evaluation area setting unit 58 sets the second evaluation area AR20 in a state where the strength of the first evaluation spectrum SP10 in the first evaluation area AR10 is reduced. . According to this configuration, the second evaluation area setting unit 58 can set the second evaluation area AR20 more accurately while being inhibited from being affected by the spectrum intensity in the first evaluation area AR10.

  Further, according to the present embodiment, the peak ratio calculation unit 45 of the reliability evaluation unit 9 has the central peak values P11 and P12 of the first evaluation spectrum SP10 and the corresponding central peak values P21 and P22 of the second evaluation spectrum SP20. Based on the ratio, the reliability determination indexes B3 and B4 are calculated. Then, the peak ratio evaluation unit 46 evaluates the reliability of the wave information based on whether or not the determination indexes B3 and B4 are equal to or greater than a predetermined threshold B34th. According to this configuration, when the central peak value P2 of the second evaluation spectrum SP20 is sufficiently smaller than the central peak value P1 of the first evaluation spectrum SP10, the reliability evaluation unit 9 uses the second evaluation spectrum SP20. The specified second largest wave in the analysis region Z10 can be determined as spectrum data having a small noise level.

  The first evaluation spectrum SP10 and the second evaluation spectrum SP20 are two-dimensional spectra in the azimuth direction θ and the frequency direction ω in polar coordinates, respectively. Then, the first evaluation spectrum SP10 and the second evaluation spectrum SP20 include orientation spectra SP11 and SP21 as spectrum components in the orientation direction θ and frequency spectra SP12 and SP22 as spectrum components in the frequency direction ω, respectively. Yes. According to this structure, the reliability evaluation part 9 can perform the reliability evaluation of wave information for every component of a spectrum. Thereby, the reliability evaluation part 9 can evaluate the reliability of wave information more correctly.

  Further, according to the present embodiment, the wave information is displayed or not displayed on the display unit 3 according to the evaluation result in the reliability evaluation unit 9. Specifically, the wave information regarding the waves evaluated as having high reliability by the reliability evaluation unit 9 is displayed on the display 3. On the other hand, the wave information about the waves evaluated as having high reliability by the reliability evaluation unit 9 is not displayed on the display 3. Thereby, only highly reliable wave information can be provided to the user.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

  (1) In the above embodiment, referring to FIG. 15, when the reliability of the first spectrum is low, specifically, the corresponding determination index in at least one of the first azimuth spectrum SP11 and the first frequency spectrum SP12. When B11 and B12 are less than the threshold value B1th (NG in step S22), the reliability of the second spectrum is not determined, but the present invention is not limited to this. For example, even when the reliability of the first spectrum is low, the reliability of the second spectrum may be determined.

  (2) In the above-described embodiment, the example of determining the reliability of the wave information regarding the two waves 101 and 102 has been described. However, the present invention is not limited to this, and it relates to three or more n (n is a natural number) waves. The reliability of the wave information may be determined. Thereby, reliability can be evaluated about the wave information of many waves.

  (3) FIG. 16 is a diagram illustrating an example of a display screen of a display device of a radar apparatus according to a modification. In the above-described embodiment, wave information with high reliability is displayed on the display device 3, while wave information with low reliability is not displayed on the display device 3, but the present invention is not limited to this. Specifically, for example, all the wave information calculated for each wave is displayed on the display regardless of the level of reliability, and at the same time, the degree of reliability for that wave is set at a position corresponding to the wave information for each wave. An indicator may be displayed. In this modification, an indicator 63 is displayed in each of the first wave display area 61 and the second wave display area 62 as an index indicating the degree of reliability of each wave. In the indicator 63 shown in FIG. 16, as the reliability increases, the length of the rectangular instruction unit 64 extends to the right and becomes longer. On the other hand, as the reliability decreases, the length of the instruction unit 64 decreases. Become.

  As described above, according to the present modification, the wave information is displayed together with the degree of reliability (in the case of the present modification, the indicator 63). Therefore, the user can view the wave information by viewing the degree of reliability. The probability of the numerical value displayed as can be grasped.

  In this modification, a bar graph-like indicator as shown in FIG. 16 is taken as an example of the indicator. However, the indicator is not limited to this, and other display methods may be used. For example, as an example, an indicator may be provided in which red is displayed when the reliability is low and orange, yellow, green, and blue gradually change in color tone as the reliability increases. In this case, the character color or the like of the wave information may be linked to the color tone of the indicator.

1 Radar device 4 Antenna (transmitter, receiver)
9 Reliability Evaluation Unit 13 Frequency Analysis Unit (Wave Number Data Acquisition Unit)
DESCRIPTION OF SYMBOLS 14 Wave information acquisition part 20 Signal processing apparatus 41 1st spectrum calculation part 42 2nd spectrum calculation part 43 1st spectrum evaluation part 44 2nd spectrum evaluation part 45 Peak ratio calculation part 46 Peak ratio evaluation part 48 First area setting for evaluation Unit 49 first spectrum extraction unit 58 second evaluation area setting unit 59 second spectrum extraction unit AR1 evaluation target area AR10, AR20 evaluation area B11, B12, B21, B22, B3, B4 reliability determination index B1th, B2th , B34th threshold value D1 Wave number data D2 Wave data P11, P12, P21, P22 Central peak value of spectrum intensity PA11, PA12, PA12, PA22 Average value of spectrum intensity SP10 First evaluation spectrum SP11, SP21 Direction Spectrum SP12, SP 2 frequency spectrum SP20 second evaluation spectrum Z1 ship surrounding area (observation area)
Z10 analysis area

Claims (16)

A wave number data acquisition unit for acquiring wave number data including the relationship between the wave number and the frequency based on the observation data obtained by observing the waves in the predetermined observation area;
A wave information acquisition unit for detecting wave data included in the wave number data by applying a predetermined filtering process to the wave number data;
For a predetermined analysis area that is a part of the observation area, a reliability evaluation unit that evaluates the reliability of the wave information specified by the wave data;
A signal processing apparatus comprising: The signal processing device according to claim 1,
The reliability evaluation unit includes a spectrum calculation unit that calculates a spectrum related to the wave based on the wave data and a spectrum evaluation unit that evaluates the reliability based on the spectrum with respect to the analysis region. A signal processing apparatus characterized by that. The signal processing apparatus according to claim 2,
The signal processing apparatus, wherein the spectrum evaluation unit evaluates the reliability based on a steepness degree of the spectrum. The signal processing device according to claim 3,
The signal processing apparatus, wherein the spectrum evaluation unit calculates the reliability determination index from a relationship between a reference value of the spectrum intensity and an average value of the spectrum intensity. The signal processing device according to claim 4,
The signal processing apparatus according to claim 1, wherein the determination index is a value obtained by dividing the reference value by the average value. The signal processing device according to claim 4 or 5, wherein
The signal processing apparatus, wherein the spectrum evaluation unit evaluates the presence or absence of the reliability based on whether or not the determination index is equal to or greater than a predetermined threshold value. The signal processing device according to any one of claims 2 to 6,
The reliability evaluation unit includes:
The wave echo intensity is displayed at each position of the ωθ coordinate specified by the angular frequency of the wave and the arrival direction of the wave, calculated based on the echo obtained from the wave included in the analysis area. a first evaluation area setting unit that sets a predetermined first evaluation area including the portion where the strongest echo intensity is observed in the ωθ spectrum as the evaluation area;
A first evaluation spectrum extraction unit for extracting a predetermined first evaluation spectrum having the largest peak value in the first evaluation area;
A first spectrum evaluation unit as the spectrum evaluation unit for determining the reliability based on the first evaluation spectrum;
A signal processing device comprising: The signal processing device according to claim 7,
The reliability evaluation unit includes:
In the area excluding the first evaluation area in the evaluation target area that is an area included in the ωθ coordinates, a predetermined second evaluation area including the place where the strongest echo intensity is observed is the evaluation area. A second evaluation area setting unit to be set as
A second evaluation spectrum extraction unit that extracts a predetermined second evaluation spectrum having a peak value in the center of the second evaluation area;
A second spectrum evaluation unit as the spectrum evaluation unit for determining the reliability based on the second evaluation spectrum;
A signal processing device comprising: The signal processing apparatus according to claim 8, comprising:
The signal processing is characterized in that the second evaluation area setting unit sets the second evaluation area in a state where the strength of the first evaluation spectrum in the first evaluation area is reduced. apparatus. The signal processing device according to claim 8 or 9, wherein
The reliability evaluation unit includes a peak ratio calculation unit,
The peak ratio calculation unit calculates the reliability determination index based on a ratio between the peak value of the first evaluation spectrum and the peak value at the center of the second evaluation spectrum. A signal processing device. The signal processing device according to claim 10,
The reliability evaluation unit includes a peak ratio evaluation unit,
The signal processing apparatus, wherein the peak ratio evaluation unit evaluates the reliability based on whether or not the determination index is equal to or greater than a predetermined threshold value. The signal processing device according to any one of claims 2 to 6,
The reliability evaluation unit includes:
The wave echo intensity is displayed at each position of the ωθ coordinate specified by the angular frequency of the wave and the arrival direction of the wave, calculated based on the echo obtained from the wave included in the analysis area. an n-th evaluation area setting unit that sets an n-th evaluation area including a portion where an n-th (n is a natural number) strong echo intensity is observed in the ωθ spectrum;
An nth evaluation spectrum extraction unit that extracts a predetermined nth evaluation spectrum having the largest peak value in the nth evaluation area;
An nth spectrum evaluation unit as the spectrum evaluation unit for determining the reliability based on the nth evaluation spectrum;
A signal processing device comprising: The signal processing device according to any one of claims 2 to 12,
The spectrum is a two-dimensional spectrum in an azimuth direction and a frequency direction in polar coordinates, and includes an azimuth spectrum as a spectrum component in the azimuth direction and a frequency spectrum as a spectrum component in the frequency direction. , Signal processing device. A transmitter for transmitting a transmission wave;
A receiver for receiving an echo returned from a reflected wave transmitted from the transmitter;
The signal processing apparatus according to any one of claims 1 to 13, which processes an echo received by the receiver.
A radar apparatus comprising: The radar apparatus according to claim 14, wherein
A display for switching the display and non-display of the wave information according to the evaluation result in the reliability evaluation unit, or displaying an index indicating the evaluation result in the reliability evaluation unit; A radar device characterized by the above. Based on the observation data obtained by observing waves in a given observation area, obtain wave number data including the relationship between wave number and frequency,
Detecting wave data included in the wave number data by applying a predetermined filtering process to the wave number data;
The signal processing method characterized by evaluating the reliability of the wave information specified by the wave data for a predetermined analysis region which is a part of the observation area.

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