Waveform information calculation device, waveform information calculation method, and program

Abstract

To reduce a probability to underestimate a size of a wave by being captured by local information in a waveform when calculating a value related to a waveform such as a wave height or a wave length.SOLUTION: A waveform information calculation device includes: data acquisition means for acquiring measurement data of a waveform; pole detection means for detecting poles in the measurement data; pole exclusion means for excluding the poles which satisfy a predetermined condition based on position relation of the poles; and waveform information calculation means for calculating at least one of a wave height and a wave length in the waveform based on the poles which are not excluded.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a waveform information calculation device, a waveform information calculation method, and a program. [Background technology]

[0002] Several techniques have been proposed for processing waveforms. For example, Patent Document 1 describes how, when a laser beam is irradiated obliquely onto the water surface, it is determined whether the laser beam has reached the trough of the wave, and if it is determined that the beam has not reached the trough, the wave height is calculated using a specified formula. Furthermore, Patent Document 2 describes a method for reducing communication traffic by detecting extreme value data based on the gradient of data sampled from a sensor and transmitting only the detected extreme value data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-133902 A [Patent Document 2] JP 2017-016187 A Summary of the Invention [Problem to be solved by the invention]

[0004] When calculating values ​​related to waveforms, such as wave height or wavelength, there may be cases where one wishes to avoid underestimating the size of the waves by being limited by local information in the waveform.

[0005] An example of an object of the present invention is to provide a waveform information calculation device, a waveform information calculation method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] According to a first aspect of the present invention, a waveform information calculation device includes: a data acquisition means for acquiring measurement data of a waveform; and an extreme point detection means for detecting an extreme point in the measurement data. If the ratio of the magnitude of the difference between the extreme values ​​of the two inner extreme points among the four consecutive extreme points to the magnitude of the difference between the extreme values ​​of the two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points, the two inner extreme points are excluded. The apparatus includes an extreme point excluding means, and a waveform information calculating means for calculating at least one of a wave height and a wavelength of the waveform based on the extreme points that have not been excluded.

[0007] According to a second aspect of the present invention, a waveform information calculation method includes acquiring measurement data of a waveform, detecting a peak in the measurement data, If the ratio of the magnitude of the difference between the extreme values ​​of the two inner extreme points among the four consecutive extreme points to the magnitude of the difference between the extreme values ​​of the two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points, the two inner extreme points are excluded. and calculating at least one of a wave height and a wavelength of the waveform based on the extreme points that have not been excluded.

[0008] According to a third aspect of the present invention, a program causes a computer to acquire measurement data of a waveform; and detect a pole in the measurement data. If the ratio of the magnitude of the difference between the extreme values ​​of the two inner extreme points among the four consecutive extreme points to the magnitude of the difference between the extreme values ​​of the two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points, the two inner extreme points are excluded. and calculating at least one of a wave height and a wavelength of the waveform based on the extreme points that have not been excluded. Effect of the Invention

[0009] According to the present invention, when calculating values ​​relating to the waveform, such as the wave height or wavelength, it is possible to reduce the possibility of underestimating the size of the waves due to being limited by local information in the waveform. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic block diagram illustrating an example of a functional configuration of a waveform information calculation device according to an embodiment. [Diagram 2] FIG. 13 is a diagram showing an example of a waveform. [Diagram 3] FIG. 13 is a diagram showing an example of a waveform when a low-pass filter is applied to the waveform. [Figure 4] FIG. 13 is a diagram showing a first example of four consecutive extreme points in measurement data. [Diagram 5]FIG. 13 is a diagram showing a second example of four consecutive extreme points in the measurement data. [Figure 6] FIG. 13 is a diagram showing a third example of four consecutive extreme points in the measurement data. [Figure 7] FIG. 13 is a diagram showing a fourth example of four consecutive extreme points in the measurement data. [Figure 8] FIG. 13 is a diagram showing a fifth example of four consecutive extreme points in the measurement data. [Figure 9] FIG. 13 is a diagram showing a sixth example of four consecutive extreme points in the measurement data. [Figure 10] FIG. 13 is a diagram showing a seventh example of four consecutive extreme points in the measurement data. [Figure 11] FIG. 13 is a diagram showing an eighth example of four consecutive extreme points in the measurement data. [Figure 12] FIG. 13 is a diagram showing a ninth example of four consecutive extreme points in the measurement data. [Figure 13] FIG. 10 is a diagram showing a tenth example of four consecutive extreme points in the measurement data. [Figure 14] FIG. 13 is a diagram showing an example of five consecutive extreme points in measurement data. [Figure 15] 4 is a flowchart showing a first example of a processing procedure for calculating waveform information by the waveform information calculation device according to the embodiment. [Figure 16] 11 is a flowchart showing a second example of the processing procedure for calculating waveform information by the waveform information calculation device according to the embodiment. [Figure 17] FIG. 2 is a schematic block diagram illustrating an example of the configuration of a control unit according to the embodiment. [Figure 18] 11A and 11B are diagrams illustrating examples of extreme values ​​excluded by an extreme point exclusion unit according to the embodiment. [Figure 19] 1 is a diagram illustrating an example of the configuration of a waveform information calculation device according to an embodiment. [Figure 20] 1 is a flowchart showing an example of a processing procedure in a waveform information calculation method according to the embodiment. [Figure 21] FIG. 1 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The following describes embodiments of the present invention, but the following embodiments do not limit the scope of the invention. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Fig. 1 is a schematic block diagram showing an example of the functional configuration of a waveform information calculation device according to an embodiment. In the configuration shown in Fig. 1, a waveform information calculation device 100 includes a communication unit 110, a display unit 120, an operation input unit 130, a storage unit 180, and a control unit 190. The control unit 190 includes a data acquisition unit 191, an extreme point detection unit 192, an extreme point removal unit 193, and a waveform information calculation unit 194.

[0012] Waveform information calculation device 100 acquires measurement data of a waveform and calculates at least one of a wave height and a wavelength. Waveform information calculation device 100 may be configured using a computer such as a personal computer (PC). In the following, an example will be described in which the waveform information calculation device 100 targets waves on the ocean surface, although the waves that the waveform information calculation device 100 targets are not limited to specific ones. Information indicating values ​​related to a waveform, such as wave height or wavelength, is referred to as “waveform information.” Calculating values ​​related to a waveform is referred to as calculating waveform information.

[0013] One problem with calculating waveform information is that it can be easy to underestimate the magnitude of a wave by relying on local information in the waveform. FIG. 2 is a diagram showing an example of a waveform. The horizontal axis (x-axis) of the graph in FIG. 2 is a coordinate axis showing position in the horizontal direction (wavelength direction). Alternatively, when observing changes in waves at the same point, the horizontal axis of the graph in FIG. 2 may be a time axis. The vertical axis (y-axis) of the graph in FIG. 2 is a coordinate axis showing position in the vertical direction (wave height direction).

[0014] Consider the case where it is desired to calculate the wave height h13 for the waveform in FIG. 2, with point P11 being the wave trough and point P14 being the wave crest. In contrast, if point P12 is treated as the crest of the wave, it is possible to calculate a wave height of h11. This can be said to be because the local maximum point P12 of the wave is treated as the crest of the wave, and the wave height is calculated as h11, which is smaller than h13. In addition, if point P13 is treated as the bottom of the wave valley, it is possible to calculate a wave height of h12. This can be said to be because the local minimum point P13 of the wave is treated as the bottom of the wave valley, and the wave height is calculated as h12, which is smaller than h13.

[0015] Local poles such as points P12 and P13 may not only actually occur in the waves to be measured, but may also occur depending on the measurement conditions of the waveform. For example, when a device for measuring waveforms is mounted on a moving object such as an airship, local poles may occur in the waveform of the measured results due to the motion of the moving object. In addition, local poles may occur in the waveform of the measured results due to the fluctuation of the reflection points on the sea surface.

[0016] One method for calculating global values ​​while ignoring local changes in the waveform is to use a low pass filter to remove information about local changes in the waveform (to smooth the waveform). However, the application of a low pass filter may change the waveform, which may cause errors in waveform information such as wave height.

[0017] 3 is a diagram showing an example of a waveform when a low-pass filter is applied to the waveform. The horizontal axis (x-axis) and vertical axis (y-axis) of the graph in FIG. 3 are the same as those in FIG. Figure 3 shows an example of applying a low-pass filter to the waveform in Figure 2. Line L11 shows the waveform in Figure 2, which corresponds to the waveform before the low-pass filter is applied. Line L12 shows the waveform after the low-pass filter is applied.

[0018] While the waveform of line L11 has four poles from points P11 to P14, the waveform of line L12 has two poles, points P21 and P22. Thus, the waveform of line L12 does not have poles corresponding to points P12 and P13. This makes it possible to avoid calculating local wave heights, so to speak, corresponding to wave heights h11 and h12 in FIG. 2.

[0019] On the other hand, the waveform after application of the low-pass filter (line L12) is changed from the waveform before application of the low-pass filter (line L11), so that the wave height h23 of line L12 is smaller than the wave height h13 of line L13. When calculating wave height based on data after applying a low-pass filter, errors occur due to changes in the waveform caused by applying the low-pass filter, such as the difference between wave height h13 and wave height h23.

[0020] Therefore, waveform information calculation device 100 excludes, from among the extreme points in the waveform, those that satisfy a predetermined condition from the extreme points used in calculating waveform information. This is expected to enable waveform information calculation device 100 to reduce the possibility of underestimating the magnitude of a wave due to being limited by local information in the waveform, and to avoid or reduce errors due to changes (distortion) in the waveform and calculate waveform information. In this respect, waveform information calculation device 100 can calculate waveform information with high accuracy. A wave based on an excluded pole, such as a wave having a crest at point P12 in FIG. 2, is also called an unwanted wave.

[0021] The communication unit 110 communicates with other devices. For example, the communication unit 110 communicates with a sensor for measuring a waveform under the control of the data acquisition unit 191, and receives a sensor signal indicating the measurement value of the waveform. Display unit 120 has a display screen, such as a liquid crystal panel or an LED (Light Emitting Diode) panel, and displays various images. Display unit 120 may display a waveform based on measurement data of the waveform and waveform information calculated by waveform information calculation device 100. The operation input unit 130 includes an input device such as a touch sensor that is provided on the display screen of the display unit 120 and configures a touch panel, and receives a user operation. For example, the operation input unit 130 may receive a user operation that instructs calculation of waveform information.

[0022] The storage unit 180 stores various types of information. For example, the storage unit 180 stores measurement data of a waveform. The storage unit 180 is configured using a storage device included in the waveform information calculation apparatus 100. The control unit 190 performs various processes by controlling each unit of the waveform information calculation device 100. The functions of the control unit 190 are performed, for example, by a CPU (Central Processing Unit) included in the waveform information calculation device 100 reading and executing a program from the storage unit 180.

[0023] The data acquiring unit 191 acquires measurement data of the waveform. For example, the data acquiring unit 191 reads out the measurement data of the waveform from a sensor signal received by the communication unit 110. The data acquisition unit 191 corresponds to an example of a data acquisition means. The data acquiring section 191 may be provided outside the control section 190. For example, the waveform information calculation device 100 may include a sensor for measuring the waveform, and the sensor may constitute the data acquiring section 191.

[0024] The waveform measurement data acquired by the data acquisition unit 191 may be data indicating the coordinate value in the horizontal direction (wavelength direction) and the coordinate value in the vertical direction (wave height direction) for each sampling point of the waveform. Alternatively, when a waveform measurement sensor measures changes in waves at the same point, the waveform measurement data acquired by the data acquisition unit 191 may be data indicating the measurement time and the coordinate value in the vertical direction (wave height direction) for each sampling point of the waveform. In the following, the horizontal coordinate or time coordinate is referred to as the x coordinate, and the vertical coordinate is referred to as the y coordinate. The measurement data of the waveform is also simply referred to as the measurement data. The sampling points of the waveform are also simply referred to as the sampling points.

[0025] The extreme point detector 192 detects extreme points in the measurement data acquired by the data acquirer 191 . The extreme point detector 192 is an example of an extreme point detection means. The pole detection unit 192 may refer to the y coordinate values ​​of the sampling points in ascending order of x coordinate values, and detect the inflection points of the y coordinate values ​​as pole points. The inflection points here are points where the y coordinate values ​​switch between increasing and decreasing. The pole detection unit 192 may detect the points where the y coordinate values ​​change from increasing to decreasing as local maximum points, and the points where the y coordinate values ​​change from decreasing to increasing as local minimum points.

[0026] The extreme point removing unit 193 removes extreme points that satisfy a predetermined condition based on the positional relationship of the multiple extreme points detected by the extreme point detecting unit 192 . The extreme point removing unit 193 corresponds to an example of an extreme point removing means.

[0027] The waveform information calculation unit 194 calculates at least one of the wave height and the wavelength of the waveform based on the extreme points not excluded by the extreme point exclusion unit 193. The waveform information calculation section 194 corresponds to an example of a waveform information calculation means. The waveform information calculation unit 194 may calculate the difference in y coordinate values ​​between adjacent maximum and minimum points as the wave height. Here, the maximum and minimum points being adjacent to each other means that there is no other peak between the maximum and minimum points in the x coordinate direction (x-axis direction).

[0028] The waveform information calculation unit 194 may calculate the difference in x-coordinate value between the maximum point and the next maximum point in the x-coordinate direction as the wavelength. Here, the fact that the next maximum point in the x-coordinate direction from the first maximum point is the second maximum point means that there is only one minimum point and no other maximum point between the two maximum points in the x-coordinate direction. The waveform information calculation unit 194 may calculate the difference in x-coordinate value between a minimum point and the next minimum point in the x-coordinate direction as the wavelength. Here, the fact that the next minimum point in the x-coordinate direction from the first minimum point is the second minimum point means that there is only one maximum point and no other maximum point between the two minimum points in the x-coordinate direction.

[0029] The extreme point exclusion unit 193 may determine whether or not to exclude two inner extreme points among four consecutive extreme points, based on at least either the difference between the extreme values ​​at these two extreme points or the wavelength calculated based on at least these two extreme points. Here, "multiple consecutive poles" means that no other poles exist between the multiple poles in the x-coordinate direction. "Excluding a pole" means that the pole is excluded from the poles used when the waveform information calculation unit 194 calculates the waveform information.

[0030] For example, the extreme point exclusion unit 193 may exclude the two inner extreme points among four consecutive extreme points if the magnitude of the difference between the extreme values ​​at these two extreme points is equal to or less than a predetermined threshold value and neither of these two extreme points corresponds to the maximum value or the minimum value among the four extreme points.

[0031] In addition, the extreme point exclusion unit 193 may exclude the two inner extreme points when the ratio of the magnitude of the difference between the extreme values ​​of the inner two extreme points among four consecutive extreme points to the magnitude of the difference between the extreme values ​​of the outer two extreme points among the four extreme points is equal to or less than a predetermined threshold value and neither of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points.

[0032] Furthermore, if the wavelength calculated based on two inner extreme points among four consecutive extreme points and any one of the four outer extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to the maximum value or minimum value among the four extreme points, the extreme point exclusion unit 193 may exclude the two inner extreme points.

[0033] 4 is a diagram showing a first example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. In the following, the four consecutive extreme points are denoted as points a, b, c, and d in ascending order of x-coordinate value. In the example of Figure 4, points a and c correspond to maximum points, and points b and d correspond to minimum points.

[0034] The x coordinates of points a, b, c, and d are x a , x b , x c , x d The y coordinates of points a, b, c, and d are expressed as y a , y b , y c , y d It is written as follows. The wave height based on points a and d is wave height h ad If point a is the maximum point, then h ad =y a -y d The wave height based on points b and c is expressed as wave height h bc When point a is a maximum point, point b is a minimum point, point c is a maximum point, and h bc =y c -y b This is expressed as:

[0035] From point a to point c, it corresponds to one period of the wave, and x c -x a This wavelength is called λ ac The point from point b to point d corresponds to one period of the wave, and x d -x b This wavelength is called λ bd It is written as follows. The waveform information calculation unit 194 may calculate these wave heights and wavelengths, or the extreme point excluding unit 193 may calculate these wave heights and wavelengths. The extreme point excluding unit 193 may exclude points b and c when formula (1) holds.

[0036]

number

[0037] "∧" means "and" (logical AND). "∨" means "or" (logical OR). "h bc The "0.3" in "≦0.3" indicates 0.3 meters (m). This "0.3" is a constant that corresponds to an example of the wave height threshold. However, the wave height threshold is not limited to a specific value. "λ ac The "5" in <5" and "λ bd The "5" in "<5" indicates 5 meters. These "5"s are constants that are examples of wavelength thresholds. However, the wavelength threshold is not limited to a specific value.

[0038] "h bc "≦0.3" corresponds to an example where the magnitude of the difference between the extreme values ​​at the two extreme points is equal to or less than a predetermined threshold. In this case, points b and c correspond to examples of the two extreme points. "y a ≧y c ∧y b ≧y d " corresponds to an example in which, when point a corresponds to a maximum point, none of the two extreme points corresponds to the maximum or minimum value among the four extreme points. In this case, points b and c correspond to examples of two extreme points.

[0039] "λ ac"≦5" corresponds to an example of a wavelength calculated based on the two inner extreme points and any one of the four outer extreme points being equal to or less than a predetermined threshold value. In this case, points b and c correspond to examples of the two inner extreme points. Point a corresponds to an example of any one of the outer extreme points of the four extreme points. "λ bd "≦5" corresponds to an example of a wavelength calculated based on the two inner extreme points and any one of the four outer extreme points being equal to or less than a predetermined threshold value. In this case, points b and c correspond to examples of the two inner extreme points. Point d corresponds to an example of any one of the outer extreme points of the four extreme points. The extreme point excluding unit 193 may exclude points b and c when equation (2) holds.

[0040]

number

[0041] "h bc / h ad The "0.2" in "≦0.2" corresponds to an example of the threshold value of the proportion of wave height. However, the threshold value of the proportion of wave height is not limited to a specific value. "h bc / h ad "≦0.2" corresponds to an example where the ratio of the magnitude of the difference between the extreme values ​​at the inner two extreme points of the four extreme points to the magnitude of the difference between the extreme values ​​at the outer two extreme points of the four extreme points is equal to or less than a predetermined threshold. In this case, points b and c correspond to examples of the inner two extreme points of the four extreme points. Points a and d correspond to examples of the outer two extreme points of the four extreme points.

[0042] 5 is a diagram showing a second example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. 5 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the example of FIG. 5, points a and c correspond to maximum points, and points b and d correspond to minimum points. In the example in Figure 5, point c corresponds to the maximum value among the four extreme points, and y a <y c In this case, "ya ≧y c ∧y b ≧y d " does not hold, the extreme point exclusion unit 193 does not exclude points b and c based on either the above formula (1) or formula (2).

[0043] 6 is a diagram showing a third example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. 6 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the example of FIG. 6, points a and c correspond to maximum points, and points b and d correspond to minimum points. In the example in Figure 6, point b corresponds to the minimum value among the four extreme points, and y b <y d In this case, "y a ≧y c ∧y b ≧y d " does not hold, the extreme point exclusion unit 193 does not exclude points b and c based on either the above formula (1) or formula (2).

[0044] 7 is a diagram showing a fourth example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. In the example of FIG. 7, points a and c correspond to minimum points, and points b and d correspond to maximum points.

[0045] If point a is a minimum point, h ad =y d -y a When point a is a minimum point, point b is a maximum point, point c is a minimum point, and h bc =y b -y c This is expressed as: The extreme point excluding unit 193 may exclude points b and c when equation (3) holds.

[0046]

number

[0047] "h" in Equation (3)bc ≦0.3∨λ ac ≦5∨λ bd "≦5" is the same as in the case of formula (1). "y a ≦y c ∧y b ≦y d " corresponds to an example in which point a corresponds to a minimum point, and none of the two extreme points corresponds to the maximum or minimum value among the four extreme points. In this case, points b and c correspond to examples of two extreme points. The extreme point excluding unit 193 may exclude points b and c when equation (4) holds.

[0048]

number

[0049] "h" in Equation (4) bc / h ad "≦0.2" is the same as in the case of formula (2).

[0050] 8 is a diagram showing a fifth example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. 8 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the example of FIG. 8, points a and c correspond to minimum points, and points b and d correspond to maximum points. In the example in Figure 8, point c corresponds to the minimum value among the four extreme points, and y a >y c In this case, "y a ≦y c ∧y b ≦y d " does not hold, the extreme point excluding unit 193 does not exclude points b and c based on either the above formula (3) or formula (4).

[0051] 9 is a diagram showing a sixth example of four consecutive extreme points in the measurement data, in which the horizontal axis of the graph in FIG. In the example of FIG. 9, points a and c correspond to minimum points, and points b and d correspond to maximum points. In the example in Figure 9, point b corresponds to the maximum value among the four extreme points, and y b >y d In this case, "y a ≦y c ∧y b ≦y d " does not hold, the extreme point excluding unit 193 does not exclude points b and c based on either the above formula (3) or formula (4).

[0052] The extreme point exclusion unit 193 may exclude an outer extreme point among the extreme points in the measurement data if the magnitude of the difference in extreme value between that extreme point and an adjacent extreme point is equal to or less than a predetermined threshold value and if the outer extreme point does not correspond to either the maximum value or the minimum value of the three outermost extreme points including that extreme point.

[0053] Fig. 10 is a diagram showing a first example of an outer pole in the measurement data, in which the horizontal axis of the graph in Fig. 10 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the example of Figure 10, three extreme points are shown, starting from the top of the measurement data. These three extreme points are denoted as points a, b, and c, starting from the top. The order from the top of the data here is in ascending order of x-coordinate value.

[0054] Point a corresponds to an example of an outermost extreme point in the measurement data. Points a, b, and c correspond to examples of the three outermost extreme points in the measurement data. In the example of Figure 10, points a and c correspond to maximum points, and point b corresponds to a minimum point. As in the case of four consecutive extreme points described above, the x-coordinates of points a, b, and c are expressed as x a , x b , x c The y coordinates of points a, b, and c are expressed as y a , y b , y c It is written as follows.

[0055] The wave height based on points a and b is wave height h ab If point a is the maximum point, then h ab =ya -y b The waveform information calculation unit 194 calculates the wave height h ab Alternatively, the pole excluding unit 193 may calculate the wave height h ab may be calculated. The extreme point excluding unit 193 may exclude the point a when the formula (5) holds.

[0056]

number

[0057] "h ab The "0.3" in "≦0.3" indicates 0.3 meters. This "0.3" is a constant that corresponds to an example of the wave height threshold. As described above, the wave height threshold is not limited to a specific value. "h ab "≦0.3" corresponds to an example where the magnitude of the difference between the extreme value of the outer pole and the extreme value adjacent to that pole is equal to or less than a predetermined threshold. As described above, point a corresponds to an example of the outer pole. Also, point b corresponds to an example of the extreme value adjacent to the outer pole. "y a ≦y c " corresponds to an example where, when point a corresponds to a local maximum point, point a does not correspond to any of the maximum or minimum values ​​of the three outermost extreme points including that extreme point.

[0058] The waveform information calculation device may also perform the same processing for the trailing extreme point in the waveform data as the processing for the leading extreme point described above. Fig. 11 is a diagram showing a second example of the outer pole in the measurement data. The horizontal axis of the graph in Fig. 11 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the example of Figure 11, three extreme points are shown, starting from the end of the entire measurement data. These three extreme points are denoted as points a, b, and c, starting from the end. The order from the end of the data here is in descending order of x-coordinate value.

[0059] As described above for the processing of the first extreme point, point a corresponds to an example of the outermost extreme point among the extreme points in the measurement data. Points a, b, and c correspond to examples of the three outermost extreme points among the extreme points in the measurement data. In the example of Figure 11, points a and c correspond to maximum points, and point b corresponds to a minimum point.

[0060] As described above for the processing of the leading pole, the x coordinate values ​​of points a, b, and c are expressed as x a , x b , x c The y coordinates of points a, b, and c are expressed as y a , y b , y c The wave height based on points a and b is expressed as wave height h ab When point a is a maximum point, point c is a maximum point, point d is a minimum point, and h ab =y a -y b The waveform information calculation unit 194 calculates the wave height h cd Alternatively, the pole excluding unit 193 may calculate the wave height h cd may be calculated. The extreme point excluding unit 193 may exclude the point a when the above formula (5) is satisfied.

[0061] Fig. 12 is a diagram showing a third example of the outer pole in the measurement data, in which the horizontal axis of the graph in Fig. 12 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. As in the case of Fig. 10, the example of Fig. 12 shows three extreme points in the entire measurement data, starting from the top. These three extreme points are denoted as points a, b, and c, starting from the top. In the example of FIG. 12, points a and c correspond to minimum points, and point b corresponds to a maximum point. If point a is a minimum point, h ab =y b -y a This is expressed as: The extreme point excluding unit 193 may exclude the point a when the formula (6) holds.

[0062]

number

[0063] "h" in Equation (6) ab "≦0.3" is the same as in the case of formula (5). "y a ≧y c " corresponds to an example where, when point a corresponds to a minimum point, point a does not correspond to any of the maximum or minimum values ​​of the three outermost extreme points including that extreme point.

[0064] Fig. 13 is a diagram showing a fourth example of the outer pole in the measurement data. The horizontal axis of the graph in Fig. 13 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. As in the case of Fig. 11, the example of Fig. 13 shows three extreme points in the entire measurement data, starting from the end. These three extreme points are denoted as points a, b, and c, starting from the end. In the example of FIG. 13, points a and c correspond to minimum points, and point b corresponds to a maximum point. The extreme point excluding unit 193 may exclude the point d when the above formula (6) is satisfied.

[0065] If the extreme point exclusion unit 193 is unable to calculate the wave height using a predetermined wave height calculation method for five consecutive extreme points centered on a maximum point, or is unable to calculate the wavelength using a predetermined wavelength calculation method, the combination of the five extreme points may be excluded from the waveform information calculation targets. The waveform information calculation section 194 may calculate the wave height and waveform at the central maximum point based on the five consecutive extreme points that have not been excluded.

[0066] Fig. 14 is a diagram showing an example of five consecutive extreme points in measurement data. The horizontal axis of the graph in Fig. 14 represents the above-mentioned x-axis, and the vertical axis represents the y-axis. In the following, the five consecutive poles are denoted as points a, b, c, d, and e in ascending order of x-coordinate value. a , x b , x c , x d , y a, y b , y c , and y d is the same as above for the case of four consecutive extreme points. Let the x-coordinate value of point e be x e The y coordinate value of point e is expressed as y e It is written as follows.

[0067] 14, points a, c, and e correspond to maximum points, points b and d correspond to minimum points, and point c corresponds to the central maximum point. Wave height h bc , wave height h cd , wavelength λ ac , and wavelength λ bd is similar to that described above for the case of four consecutive extreme points. From point c to point e corresponds to one period of the wave, and x e -x c corresponds to the wavelength. This wavelength is called λ ce It is written as follows.

[0068] The pole excluding unit 193 may select the maximum points in the observation data one by one in ascending order of x-coordinate value, and determine whether it is possible to select a combination of five consecutive pole points centered on the selected maximum point. If it is possible to select a combination of five consecutive pole points, the pole excluding unit 193 may further select the wave height h bc and h cd and wavelength λ ac , λ bd , and λ ce It may be determined whether or not it is possible to calculate

[0069] For example, if the maximum point selected by the pole point excluding unit 193 is one located at the end in the x-coordinate direction among the maximum points in the observation data, it may be impossible to select a combination of five consecutive pole points centered on that maximum point. Also, if the combination of five pole points selected by the pole point excluding unit 193 includes a pole point whose y-coordinate value cannot be determined due to a measurement error, it may be impossible to calculate the wave height or wavelength.

[0070] When the extreme point excluding unit 193 determines that it is possible to select a combination of five extreme points and to calculate the above-mentioned peak height and wavelength, the waveform information calculating unit 194 may calculate the peak height and wavelength at the central maximum point based on the data of the five extreme points. In the example of Fig. 14, point c corresponds to an example of the central maximum point.

[0071] For example, the waveform information calculation unit 194 hb c and h cd The larger of these may be calculated as the wave height at the central maximum point. In this case, the wave height at the central maximum point is calculated as MAX(h ac ,h cd ) “MAX” is a function that outputs the maximum value of its arguments.

[0072] In addition, the waveform information calculation unit 194 calculates the wavelength λ ac , λ bd , and λ ce The wavelength at the central maximum point may be calculated as the wavelength at the central maximum point. In this case, the wavelength at the central maximum point is calculated as MIN(λ ac ,λ bd ,λ ce ) “MIN” is a function that outputs the smallest value among its arguments.

[0073] FIG. 15 is a flowchart showing a first example of a processing procedure by the waveform information calculation device 100 to calculate waveform information. In the process of FIG. 15, the data acquisition unit 191 acquires measurement data (step S111). The extreme point detector 192 detects extreme points in the measurement data acquired by the data acquirer 191 (step S112).

[0074] The extreme point excluding unit 193 determines four consecutive points from among the extreme points detected by the extreme point detecting unit 192 (step S113). Then, the waveform information calculating unit 194 calculates the wavelength and the wave height at the four points determined by the extreme point excluding unit 193 (step S114). Alternatively, the extreme point excluding unit 193 may calculate the wavelength and the wave height. The extreme point excluding unit 193 excludes the extreme points that satisfy a predetermined condition based on the calculated wavelength and wave height (step S115). As described with reference to Fig. 4 to Fig. 9, when four consecutive extreme points satisfy formula (5) or formula (6), the extreme point excluding unit 193 may exclude the inner two extreme points of the four extreme points.

[0075] Then, the extreme point excluding unit 193 judges whether or not a termination condition for the process of excluding an extreme point is satisfied (step S116). The termination condition for the process of excluding an extreme point is not limited to a specific condition. For example, the termination condition for the process of excluding an extreme point may be, but is not limited to, that no extreme point is deleted no matter how four consecutive points are selected.

[0076] If the extreme point excluding unit 193 determines that the end condition for the process of excluding the extreme point is not satisfied (step S116: NO), the process returns to step S113. On the other hand, when it is determined that the end condition for the process of excluding the extreme point is satisfied (step S116: YES), the extreme point excluding unit 193 excludes an outer extreme point in the entire measurement data if a predetermined condition is satisfied for that extreme point (step S117). As described with reference to Figs. 10 to 13, the extreme point excluding unit 193 may exclude the first extreme point if the first three consecutive extreme points satisfy formula (5) or formula (6). Also, the extreme point excluding unit 193 may exclude the last extreme point if the last three consecutive extreme points satisfy formula (5) or formula (6).

[0077] Next, the waveform information calculation unit 194 calculates waveform information based on the extreme points that have not been excluded (step S118). The waveform information calculation device 100 outputs the calculated waveform information (step S119). The method by which the waveform information calculation device 100 outputs the waveform information is not limited to a specific method. For example, the display unit 120 may display the waveform information under the control of the control unit 190, but is not limited to this. After step S119, the waveform information calculating device 100 ends the process of FIG.

[0078] Fig. 16 is a flowchart showing a second example of the procedure of the process of calculating waveform information by the waveform information calculation device 100. The waveform information calculation device 100 may perform the process of Fig. 16 in step S119 of Fig. 15. Alternatively, the waveform information calculation device 100 may perform the process of Fig. 16 separately from the process of Fig. 15 based on the pole detected by the pole detection section 192.

[0079] 16, the pole excluding unit 193 selects one maximum point from among the poles in the measurement data (step S211). For example, the pole excluding unit 193 may select the maximum points in the observation data one by one in ascending order of x-coordinate value, but is not limited to this. Next, the extreme point removal unit 193 determines whether or not it is possible to select five consecutive extreme points centered on the selected maximum point (step S212).

[0080] If the extreme point exclusion unit 193 determines that the five extreme points are unselectable (step S212: NO), the process returns to step S211. On the other hand, if the extreme point excluding unit 193 determines that five extreme points can be selected (step S212: YES), the waveform information calculation unit 194 attempts to calculate the wave height and wavelength exemplified in Fig. 14 (step S213). Then, the waveform information calculation unit 194 determines whether or not the calculation of the wave height and wavelength has been successful (step S214). The extreme point excluding unit 193 may perform the processes of steps S213 and S214 instead of the waveform information calculation unit 194.

[0081] If the waveform information calculation unit 194 determines that the calculation of the wave height and wavelength has failed (step S214: NO), the process returns to step S211. On the other hand, if it is determined that the calculation of the pulse height and wavelength has been successful (step S214: YES), the waveform information calculation unit 194 calculates the pulse height and wavelength at the central maximum point based on the pulse height and wavelength calculated in step S213 (step S215).

[0082] Next, the extreme point excluding unit 193 judges whether or not a termination condition for the waveform information calculation is satisfied (step S216). The termination condition for the waveform information calculation is not limited to a specific condition. For example, the extreme point excluding unit 193 may determine whether or not the process from step S211 to S215 has been performed for all maximum points in the measurement data, but is not limited thereto.

[0083] If the extreme point excluding unit 193 determines that the end condition is not satisfied (step S216: NO), the process returns to step S211. On the other hand, if the extreme point excluding unit 193 determines that the end condition is satisfied (step S216: YES), the waveform information calculating device 100 ends the processing of FIG. When the process of Fig. 16 is performed separately from the process of Fig. 15, the waveform information calculation device 100 outputs the calculated waveform information after the process of Fig. 16 is completed. The method of the waveform information calculation device 100 outputting the waveform information is not limited to a specific method. For example, the display unit 120 may display the waveform information under the control of the control unit 190, but is not limited to this.

[0084] Fig. 17 is a schematic block diagram showing an example of the configuration of the control unit 190. Fig. 17 shows an example in which the waveform information calculation device 100 is mounted on a flying boat. In the configuration shown in FIG. 17, the control unit 190 includes an acceleration correction unit 201, a pitch / roll correction unit 202, a low-pass filter 203, and a measurement result screen output unit 204, in addition to the pole detection unit 192, the pole removal unit 193, and the waveform information calculation unit 194 shown in FIG. 1. 17 shows an example in which the data acquisition unit 191 is configured externally to the control unit 190. Alternatively, the control unit 190 may further include the data acquisition unit 191 in addition to the units in FIG.

[0085] The acceleration correction unit 201 corrects the measurement data in accordance with the acceleration of the flying boat. For example, the acceleration correction unit 201 may thin out and interpolate sample points so that the intervals between sample points in the x coordinate direction are constant regardless of the acceleration or deceleration of the flying boat. The pitch / roll correction unit 202 corrects the measurement data according to the inclination of the flying boat's body. For example, the pitch / roll correction unit 202 may correct the y-coordinate value of the measurement data according to the inclination of the flying boat's body, thereby obtaining data similar to that obtained when the body is not inclined.

[0086] The low-pass filter 203 removes unnecessary high-frequency components from the measurement data. The control unit 190 may determine the cutoff frequency (Fc) of the low-pass filter 203 based on the speed of the flying boat and the minimum wavelength unnecessary for measurement. In addition, control unit 190 may set a cutoff frequency or turn off low-pass filter 203 so as to suppress distortion of the waveform caused by application of low-pass filter 203, depending on the accuracy required for measuring the waveform.

[0087] The measurement result screen output unit 204 displays the waveform measurement results on the display unit 120. For example, the measurement result screen output unit 204 may display the waveform indicated by the measurement data and the waveform information calculated by the waveform information calculation unit 194 on the display unit 120.

[0088] Fig. 18 is a diagram showing an example of extreme values ​​excluded by the extreme point exclusion section 193. The horizontal axis of the graph in Fig. 18 indicates the x coordinate, and the vertical axis indicates the y coordinate. A line L21 shows an example of a waveform before application of the low-pass filter 203. A line L22 shows an example of a waveform after application of the low-pass filter 203.

[0089] Among the poles of the waveform after application of the low-pass filter 203, the poles excluded by the pole removing section 193 are indicated by squares, and the remaining poles (poles that are not excluded) are indicated by circles. By applying the low-pass filter 203 and removing the poles by the pole removing unit 193, it is possible to reduce the possibility of underestimating the wave magnitude due to being influenced by local information in the waveform.

[0090] As described above, data acquisition unit 191 acquires measurement data of a waveform. Pole detection unit 192 detects poles in the measurement data. Pole exclusion unit 193 excludes poles that satisfy a predetermined condition based on the positional relationship of a plurality of poles. Waveform information calculation unit 194 calculates at least one of the wave height and wavelength of the waveform based on the poles that have not been excluded. It is expected that waveform information calculation device 100 can calculate waveform information by reducing the possibility of underestimating the magnitude of a wave due to being limited by local information in the waveform, and by avoiding or reducing errors due to changes (distortion) in the waveform. In this respect, waveform information calculation device 100 can calculate waveform information with high accuracy.

[0091] By continuously performing the extreme value selection process by the extreme point excluding unit 193, it is possible to reduce the influence of the oscillation of the waveform information calculation device 100 and fluctuations in reflection points on the sea surface, and to measure wave height data quickly and without compromising the wave height. Furthermore, by the extreme point excluding unit 193 selecting extreme values ​​(excluding extreme values ​​that are not selected), it is possible to avoid or reduce distortion of the wave height data caused by application of a low-pass filter, and it is possible to calculate waveform information with high accuracy. Moreover, the process performed by the extreme point excluding unit 193 is not a process that targets all data, as in filtering, but is a process that focuses on extreme values, and the amount of data to be processed is extremely small, making it possible to perform high-speed processing.

[0092] Furthermore, for the two inner extreme points among the four consecutive extreme points, the extreme point exclusion unit 193 determines whether or not to exclude these two extreme points based on at least either the difference between the extreme values ​​at these two extreme points or the wavelength calculated based on at least these two extreme points. The extreme point exclusion unit 193 can determine whether or not to exclude a pole using a wavelength based on the difference between the extreme values ​​and the difference between the x-coordinates of the poles, and in this respect, the load on the extreme point exclusion unit 193 can be light.

[0093] In addition, the extreme point exclusion unit 193 excludes the two inner extreme points among the four extreme points if the magnitude of the difference between the extreme values ​​at these two extreme points is equal to or less than a predetermined threshold value and neither of these two extreme points corresponds to the maximum value or the minimum value among the four extreme points. The extreme point exclusion unit 193 can determine whether or not to exclude an extreme point by relatively simple processing, such as comparing the magnitude of the difference between the extreme values ​​with a threshold value and judging whether the extreme point is the maximum or minimum value among the four extreme points. In this respect, the load on the extreme point exclusion unit 193 is light.

[0094] In addition, the extreme point exclusion unit 193 excludes the two inner extreme points if the ratio of the magnitude of the difference between the extreme values ​​of the two inner extreme points among the four extreme points to the magnitude of the difference between the extreme values ​​of the two outer extreme points among the four extreme points is equal to or less than a predetermined threshold value and neither of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points. The extreme point exclusion unit 193 can determine whether or not to exclude an extreme point by relatively simple processing, such as comparing the ratio of the magnitude of the difference between the extreme values ​​with a threshold value, and judging whether the extreme point is the maximum or minimum value among the four extreme points. In this respect, the load on the extreme point exclusion unit 193 is light.

[0095] Furthermore, for two inner extreme points among the four extreme points, if the wavelength calculated based on these two extreme points and any one of the outer extreme points among the four extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either the maximum value or the minimum value among the four extreme points, the extreme point exclusion unit 193 excludes the two inner extreme points. The extreme point exclusion unit 193 can determine whether or not to exclude a pole point by relatively simple processing, such as comparing the wavelength based on the x-coordinate of the pole point with a threshold value and judging whether the pole point is the maximum or minimum value among the four pole points. In this respect, the load on the extreme point exclusion unit 193 is light.

[0096] Furthermore, for an outer extreme point among four consecutive extreme points, if the magnitude of the difference in extreme value between the outer extreme point and an extreme point adjacent to it is equal to or less than a predetermined threshold value and the outer extreme point does not correspond to either the maximum value or the minimum value among the four extreme points, the extreme point exclusion unit 193 excludes the outer extreme point. The extreme point exclusion unit 193 can determine whether or not to exclude an extreme point by relatively simple processing, such as comparing the magnitude of the difference between the extreme values ​​with a threshold value and judging whether the extreme point is the maximum or minimum value among the four extreme points. In this respect, the load on the extreme point exclusion unit 193 is light.

[0097] Furthermore, when the peak exclusion unit 193 is unable to calculate the peak height or the wavelength of five consecutive peaks centered around a maximum peak using a predetermined peak height calculation method, the unit excludes the combination of the five peaks from the waveform information calculation targets. The waveform information calculation unit 194 calculates the peak height and waveform at the central maximum peak based on the five consecutive peaks that were not excluded. According to the waveform information calculation device 100, it is possible to calculate the wave height and wavelength for each maximum point of the waveform data.

[0098] Fig. 19 is a diagram showing an example of the configuration of a waveform information calculation device according to an embodiment. A waveform information calculation device 610 shown in Fig. 19 includes a data acquisition section 611, an extreme point detection section 612, an extreme point removal section 613, and a waveform information calculation section 614. In this configuration, the data acquisition unit 611 acquires measurement data of the waveform. The pole detection unit 612 detects poles in the measurement data. The pole exclusion unit 613 excludes poles that satisfy a predetermined condition based on the positional relationship of multiple poles. The waveform information calculation unit 614 calculates at least one of the wave height and wavelength of the waveform based on the poles that were not excluded.

[0099] The data acquiring unit 611 corresponds to an example of a data acquiring means. The extreme point detecting unit 612 corresponds to an example of an extreme point detecting means. The extreme point removing unit 613 corresponds to an example of an extreme point removing means. The waveform information calculating unit 614 corresponds to an example of a waveform information calculating means. It is expected that the waveform information calculation device 610 can calculate waveform information by reducing the possibility of underestimating the magnitude of a wave due to being limited by local information in the waveform, and by avoiding or reducing errors due to changes (distortion) in the waveform. In this respect, the waveform information calculation device 610 can calculate waveform information with high accuracy.

[0100] FIG. 20 is a flowchart illustrating an example of a processing procedure in a waveform information calculation method according to the embodiment. The process shown in FIG. 20 includes acquiring data (step S611), detecting extreme points (step S612), removing the extreme points (step S613), and calculating waveform information (step S614). It includes acquiring data (step S611), detecting extreme points (step S612), removing the extreme points (step S613), and calculating waveform information (step S614).

[0101] In acquiring data (step S611), measurement data of a waveform is acquired. In detecting poles (step S612), poles in the measurement data are detected. In removing poles (step S613), poles that satisfy a predetermined condition are removed based on the positional relationship of a plurality of poles. In calculating waveform information (step S614), at least one of a wave height and a wavelength of the waveform is calculated based on the poles that were not removed. The process shown in Fig. 20 is expected to reduce the possibility of underestimating the magnitude of a wave due to being limited by local information in the waveform, and to avoid or reduce errors due to changes (distortion) in the waveform while calculating waveform information. In this respect, the process shown in Fig. 20 allows waveform information to be calculated with high accuracy.

[0102] FIG. 21 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment. In the configuration shown in FIG. 7, a computer 700 includes a CPU (Central Processing Unit) 710, a main memory device 720, an auxiliary memory device 730, and an interface 740.

[0103] Any one or more of the above-mentioned waveform information calculation device 100 and waveform information calculation device 610 may be implemented in a computer 700. In this case, the operation of each of the above-mentioned processing units is stored in the auxiliary storage device 730 in the form of a program. The CPU 710 reads the program from the auxiliary storage device 730, loads it in the main storage device 720, and executes the above-mentioned processing according to the program. The CPU 710 also secures a storage area in the main storage device 720 to be used for the above-mentioned processing according to the program.

[0104] When the waveform information calculating device 100 is implemented in a computer 700, the operations of the control unit 190 and each of its units are stored in the form of a program in an auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-mentioned processing in accordance with the program. Furthermore, the CPU 710 allocates a storage area corresponding to the storage unit 180 in the main storage device 720 in accordance with the program.

[0105] The communication by the communication unit 110 is performed by the interface 740 having a communication function and performing communication under the control of the CPU 710. Display by the display unit 120 is performed by the interface 740 having a display screen and displaying various images under the control of the CPU 710. Reception of a user operation by the operation input unit 130 is performed by the interface 740 having an input device, receiving the user operation, and outputting a signal indicating the received user operation to the CPU 710.

[0106] When the waveform information calculation device 610 is implemented in the computer 700, the operations of the data acquisition unit 611, the extreme point detection unit 612, the extreme point removal unit 613, and the waveform information calculation unit 614 are stored in the form of a program in the auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-mentioned processing in accordance with the program. Furthermore, the process of the data acquisition unit 611 acquiring the measurement data of the waveform is executed, for example, by the interface 740 having a communication function and communicating with other devices such as a sensor under the control of the CPU 710.

[0107] Note that a program for realizing all or part of the functions of the waveform information calculation device 100 and the waveform information calculation device 610 may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to process each part. The term "computer system" as used herein includes hardware such as an OS (operating system) and peripheral devices. "Computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), as well as storage devices such as hard disks built into computer systems. The above-mentioned program may be for realizing part of the above-mentioned functions, or may be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

[0108] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not deviate from the gist of the present invention are also included. [Explanation of symbols]

[0109] 100, 610 Waveform information calculation device 110 Communications Department 120 Display section 130 Operation input section 180 Storage section 190 Control section 191, 611 Data Acquisition Section 192, 612 Pole detector 193, 613 Pole exclusion section 194, 614 Waveform information calculation section 201 Acceleration correction unit 202 Pitch / Roll Compensation Unit 203 Low-pass filter 204 Measurement result screen output section

Claims

1. A data acquisition means for acquiring waveform measurement data; an extreme point detection means for detecting an extreme point in the measurement data; an extreme point excluding means for excluding the two inner extreme points when a ratio of a magnitude of a difference between extreme values ​​of the two inner extreme points among the four consecutive extreme points to a magnitude of a difference between extreme values ​​of the two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value and neither of the two inner extreme points corresponds to a maximum value or a minimum value among the four extreme points; a waveform information calculation means for calculating at least one of a wave height and a wavelength of the waveform based on the extreme points that have not been excluded; A waveform information calculation device comprising:

2. the extreme point excluding means excludes, for two inner extreme points among the four extreme points, when a wavelength calculated based on these two extreme points and any one of the outer extreme points among the four extreme points is equal to or less than a predetermined threshold value, and when neither of the two inner extreme points corresponds to a maximum value or a minimum value among the four extreme points; The waveform information calculation device according to claim 1 .

3. the extreme point excluding means excludes an outer extreme point among the extreme points in the measurement data if a magnitude of a difference between an extreme value of the outer extreme point and an extreme point adjacent to the outer extreme point is equal to or less than a predetermined threshold value and the outer extreme point does not correspond to any of the maximum value or the minimum value of the three outer extreme points including the outer extreme point; The waveform information calculation device according to claim 1 or 2.

4. the extreme point excluding means excludes a combination of five consecutive extreme points centered on a maximum point from the waveform information calculation targets when the wave height cannot be calculated by a predetermined wave height calculation method or the wavelength cannot be calculated by a predetermined wavelength calculation method; the waveform information calculation means calculates a wave height and a waveform at the central maximum point based on the five consecutive extreme points that have not been excluded. The waveform information calculation device according to claim 1 .

5. Obtaining measurement data of a waveform; Detecting extreme points in the measurement data; If a ratio of a magnitude of a difference between extreme values ​​at two inner extreme points among four consecutive extreme points to a magnitude of a difference between extreme values ​​at two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either a maximum value or a minimum value among the four extreme points, the two inner extreme points are excluded; Calculating at least one of a wave height and a wavelength of the waveform based on the non-excluded extreme points; A waveform information calculation method comprising the steps of:

6. On the computer, Obtaining measurement data of a waveform; Detecting extreme points in the measurement data; If a ratio of a magnitude of a difference between extreme values ​​at two inner extreme points among four consecutive extreme points to a magnitude of a difference between extreme values ​​at two outer extreme points among the four consecutive extreme points is equal to or less than a predetermined threshold value, and none of the two inner extreme points corresponds to either a maximum value or a minimum value among the four extreme points, the two inner extreme points are excluded; Calculating at least one of a wave height and a wavelength of the waveform based on the non-excluded extreme points; A program for executing the above.

Images