Observation program, observation method, observation device, and observation system

Abstract

To provide a novel technique of observing change of a water surface different from a wave.SOLUTION: The observation program causes a computer to execute processing of: acquiring data of a radar image formed by periodically observing a sea area as an observation target by a radar device using electric waves of 0.01 m-2 m lengths; calculating an average image formed by averaging the radar image shown by the acquired data at every specific average time in order of the observation times; and outputting information based on the calculated average image.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an observation program, an observation method, an observation device, and an observation system. [Background technology]

[0002] For example, at power plants such as thermal and nuclear power plants, seawater is taken in through an intake, the steam generated after turning the turbines is cooled with seawater, and the heated seawater (warm wastewater) is then returned to the ocean through an outlet. In the ocean where the warm wastewater is discharged, jets are formed by the warm wastewater, causing the temperature to rise. When siting a power plant, electric utilities are required to investigate the actual spread of warm wastewater through environmental assessments and take measures to address the issue. For example, in consideration of the impact of warm wastewater on fishery resources and aquatic life, the location of the outlet must be set to limit the range of water temperature rise caused by the warm wastewater. Furthermore, because taking in seawater whose temperature has risen due to the warm wastewater reduces cooling efficiency, the intake must be set with consideration given to the recirculation of the warm wastewater.

[0003] The range where the temperature rises due to the heated wastewater is identified by observing the jet of the heated wastewater. Conventional techniques for observing the jet of heated wastewater from power plants include offshore observation by ship, observation by marine radar, observation by buoy, and observation by fixed camera. Non-Patent Document 1 also reports that the river front can be clearly identified in radar images taken with X-band radar. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Takewaka.Satoshi,“Visibility of River Plume Fronts with an X-Band Radar.”,Journal of Sensors 2016:e6594847,13 Dec 2015 Summary of the Invention [Problem to be solved by the invention]

[0005] However, ocean observations using ships are expensive because they require the use of ships, and whether or not observations can be carried out depends on oceanographic conditions. For example, observations cannot be carried out when the sea is rough or in weather conditions unsuitable for observation, such as when there is fog. Ocean radar can measure surface currents using radio waves in the VHF to HF bands, but the jets cannot be observed sufficiently because the range of diffusion of the jets is too close and the spatial resolution is low. Buoy observations can observe jets by releasing a buoy from a water outlet, but this depends on oceanographic conditions. Fixed camera observations cannot be carried out during dark hours.

[0006] Furthermore, Non-Patent Document 1 is intended to observe the river front where freshwater from the river mouth mixes with saltwater from the sea, and is unable to observe jets.

[0007] In the ocean area where the jet flows, the jet generates water surface fluctuations that are different from those of ocean waves. Therefore, by observing water surface fluctuations that are different from those of ocean waves, it is possible to observe, for example, the jet. Also, by observing water surface fluctuations that are different from those of ocean waves, it is possible to observe, for example, gas leaks on the seabed.

[0008] The present invention has been made in view of the above, and aims to provide a new technique for observing water surface fluctuations other than waves. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the objectives, the observation program of the present invention causes a computer to acquire radar image data obtained by periodically observing the target sea area using a radar device that uses radio waves with a wavelength of 0.01 m to 2 m, calculate an average image by averaging the radar images shown by the acquired data for each specified averaging time in the order of the observation time, and output information based on the calculated average image. [Effects of the Invention]

[0010] The present invention has an effect of providing a new technique for observing water surface fluctuations other than ocean waves. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an observation system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a functional configuration of an observation device according to an embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a radar image according to the embodiment. [Figure 4A] FIG. 4A is a diagram illustrating observation by a radar according to an embodiment. [Figure 4B] FIG. 4B is a diagram illustrating the effect of time-averaging the observation results by the radar according to the embodiment. [Figure 5A] FIG. 5A is a diagram illustrating an example of an average image according to the embodiment. [Figure 5B] FIG. 5B is a diagram illustrating an example of an average image according to the embodiment. [Figure 5C] FIG. 5C is a diagram illustrating an example of an average image according to the embodiment. [Figure 5D] FIG. 5D is a diagram illustrating an example of an average image according to the embodiment. [Figure 5E] FIG. 5E is a diagram illustrating an example of an average image according to the embodiment. [Figure 5F] FIG. 5F is a diagram illustrating an example of an average image according to the embodiment. [Figure 5G] FIG. 5G is a diagram illustrating an example of an average image according to the embodiment. [Figure 6] FIG. 6 is a flowchart illustrating an example of a procedure of the observation process according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating a computer that executes an observation program. DETAILED DESCRIPTION OF THE INVENTION

[0012] Below, embodiments of the observation program, observation method, observation device, and observation system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. Furthermore, each embodiment can be appropriately combined within the scope of not causing any contradiction in the processing content. [Example]

[0013] In the embodiments, a case where water surface fluctuations other than waves are observed to observe water surface fluctuations caused by jets is mainly described. Also, in the embodiments, a case where water surface fluctuations other than waves caused by jets of heated wastewater discharged into the sea from a discharge outlet at a power plant such as a thermal power plant or a nuclear power plant is mainly described.

[0014] [Typical configuration of observation system] A typical configuration of an observation system according to this embodiment will be described. Fig. 1 is a diagram showing an example of the configuration of an observation system according to this embodiment. The observation system 10 includes a radar device 11 and an observation device 12.

[0015] The radar device 11 detects targets by emitting radio waves with wavelengths of 0.01 m to 2 m and capturing the reflected waves. In this embodiment, a marine radar device is used as the radar device 11. The radar device 11 detects targets using X-band or S-band radio waves. The radar device 11 has a directional antenna, and by rotating the antenna horizontally, it is possible to detect targets all around the horizontal direction. The radar device 11 alternates between transmitting and receiving radio waves using the antenna. The radar device 11 measures the distance to the target from the time between transmitting radio waves and receiving reflected waves using the antenna, and measures the direction of the target from the orientation of the antenna. The radar device 11 generates radar image data that maps the detected targets. During observation, the radar device 11 periodically observes radar image data and stores it as observation data, correlating it with the observation time. After the observation is completed, the radar device 11 outputs the observation data to the observation device 12. The radar device 11 may output the generated radar image data to the observation device 12 as needed, in association with the observation time.

[0016] The observation device 12 is a device used to observe the jet. The observation device 12 is, for example, a computer such as a personal computer or a server computer. The observation device 12 may be implemented as a single computer, or may be implemented as a computer system consisting of multiple computers. In this embodiment, the case where the observation device 12 is a single computer will be described as an example.

[0017] The observation device 12 analyzes the radar image data input from the radar device 11 and observes water surface fluctuations other than ocean waves.

[0018] The observation system 10 according to the embodiment periodically observes the target sea area using a radar device 11, and analyzes the observed radar image data using an observation device 12 to observe the jet.

[0019] [Configuration of observation equipment 12] Next, we will explain the configuration of the observation device 12. Figure 2 is a diagram showing an example of the functional configuration of the observation device 12 according to the embodiment. The observation device 12 has an external interface unit 20, an operation unit 21, a display unit 22, a storage unit 23, and a control unit 24.

[0020] The external interface unit 20 is an interface that transmits and receives various types of information to and from other devices. The external interface unit 20 is connected to a network or a communication bus and transmits and receives various types of information. For example, the external interface unit 20 receives radar image data from the radar device 11 via the network.

[0021] The operation unit 21 is an input device that accepts input of various operations. Examples of the operation unit 21 include input devices that accept operation input, such as a mouse and a keyboard. The operation unit 21 accepts input of various information. The operation unit 21 accepts operation input from a user and inputs operation information indicating the content of the accepted operation to the control unit 24.

[0022] The display unit 22 is a display device that displays various types of information. Examples of the display unit 22 include display devices such as an LCD (Liquid Crystal Display) and a CRT (Cathode Ray Tube). The display unit 22 displays various types of information. For example, the display unit 22 displays various screens such as an operation screen. The observation device 12 may receive access from an external terminal device used by an administrator or the like, display various screens such as an operation screen on the terminal device, and receive operation input from the various screens.

[0023] The storage unit 23 is a storage device that stores various types of data. For example, the storage unit 23 is a storage device such as a hard disk, a solid state drive (SSD), an optical disk, etc. The storage unit 23 may also be a semiconductor memory in which data can be rewritten, such as a random access memory (RAM), a flash memory, or a non-volatile static random access memory (NVSRAM).

[0024] The storage unit 23 stores an OS (Operating System) and various programs executed by the control unit 24. For example, the storage unit 23 stores various programs including an observation program that executes the observation process described below. Furthermore, the storage unit 23 stores various data used by the programs executed by the control unit 24. For example, the storage unit 23 stores observation data 30.

[0025] The observation data 30 is data observed by the radar device 11. For example, the observation data 30 stores radar image data in association with observation time.

[0026] The control unit 24 is a device that controls the observation device 12. The control unit 24 can be an electronic circuit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 24 has an internal memory for storing programs that define various processing procedures and control data, and executes various processes using these. The control unit 24 functions as various processing units when various programs are run. For example, the control unit 24 has an acquisition unit 40, a calculation unit 41, and an output unit 42.

[0027] The acquisition unit 40 acquires radar image data obtained by periodically observing the sea area to be observed by the radar device 11. For example, when the radar device 11 generates observation data including radar image data obtained by periodically observing the sea area to be observed, the acquisition unit 40 acquires the observation data from the radar device 11 or an external device that stores the observation data, and stores the acquired observation data in the storage unit 23 as observation data 30. When the radar device 11 transmits radar image data as needed, the acquisition unit 40 acquires radar image data received from the radar device 11 via the external interface unit 20. The acquisition unit 40 associates the acquired radar image data with observation time and stores it in the storage unit 23 as observation data 30. The observation time may be transmitted by the radar device 11 to the observation device 12 in association with the radar image data. The observation time may also be the time when the radar device 11 receives the radar image data.

[0028] The calculation unit 41 calculates an average image by averaging radar images represented by the data acquired by the acquisition unit 40 for each predetermined averaging time in the order of the observation times. For example, the calculation unit 41 reads radar images from the observation data 30 stored in the storage unit 23 in the order of observation time, and calculates an average image by averaging each radar image whose observation time falls within each averaging time. For each radar image that falls within the averaging time, the calculation unit 41 calculates an average value of pixel values ​​of pixels at the same position for each pixel position in the radar image, and calculates an average image with the average value as the pixel value for each pixel position in the radar image.

[0029] Here, waves propagate in the sea. Also, in the sea area where the heated wastewater is released from the outlet, a jet of the released heated wastewater is formed. As a result, in the sea area where the heated wastewater is released, the jet causes water surface fluctuations that are different from waves.

[0030] The radar device 11 detects targets by emitting radio waves and capturing the reflected waves. As a result, images of waves and jets appear in radar images observed by the radar device 11. For example, the radar device 11 is a radar device for ships that uses radio waves in the X-band or S-band. The X-band has a wavelength of 3 cm (0.03 m), and the S-band has a wavelength of 10 cm (0.1 m), and these are strongly reflected (Bragg scattering) by waves and disturbances (structures) of approximately 1.5 cm and 5 cm, respectively. The radar device 11 can detect the shape of the water surface (waves) based on the strength of scattering.

[0031] FIG. 3 is a diagram showing an example of a radar image according to the embodiment. FIG. 3 is a radar image obtained by observing, using a radar device 11, an ocean area where a power plant is discharging heated wastewater from a water outlet. FIG. 3 shows a radar image including an image of a detected target in a semicircular shape centered on the position of the radar device 11. FIG. 3 also shows the direction and distance of the radar image. The radar image shows two breakwaters BW1 and BW2 existing in the ocean area. In FIG. 3, a water outlet is installed at the base of breakwater BW1, and heated wastewater is being discharged from the outlet. FIG. 3 also shows an image of waves. In addition, an image of water surface fluctuations caused by the jet of heated wastewater discharged from the outlet is shown, extending linearly from near the base of breakwater BW1.

[0032] Waves propagate across the water surface and periodically appear at various locations in the ocean. On the other hand, jets are flows of seawater released from a water outlet that diffuse into the ocean. When turbulent structures form near the water surface, minute changes in the water surface shape appear irregularly as the flow converges and diverges. These changes in the water surface shape have a shorter period (wavelength) than normal waves, and they repeatedly appear and disappear within a short period of time. Therefore, high-frequency observations using a radar device using radio waves with wavelengths of 0.01 m to 2 m, which are close to the wavelengths of the water surface shape, can capture the water surface shape caused by turbulent structures as changes in scattering intensity. In this embodiment, the radar device 11 is a marine radar device, and the radio wave wavelength is X-band or S-band, but this is not limited thereto. The wavelength of the radio waves emitted by the radar device 11 may be any radio wave with a wavelength of 0.01 m to 2 m. For example, the radar device 11 may periodically observe the ocean using radio waves of any of X-band, C-band, S-band, and L-band.

[0033] As mentioned above, waves propagate across the water surface and periodically appear at various locations in the ocean. Therefore, by averaging periodically observed radar images, the waves are averaged out in the average image, making them less noticeable.

[0034] Figure 4A is a diagram illustrating radar observations according to an embodiment. Figure 4A illustrates the conditions of jets and waves and the resulting radio wave scattering. In Figure 4A, in addition to oceanic waves, minute water surface fluctuations occur within the range of the jet's influence. Radio wave scattering occurs due to both waves and water surface fluctuations. Water surface fluctuations caused by jets are close to the wavelength at which radio waves are strongly scattered, resulting in strong scattering. Water surface fluctuations can also occur at tidal ridges (boundaries between different water qualities) due to the convergence of currents. Water surface fluctuations caused by jets repeatedly form and disappear, and they do not always form in the same place. Therefore, instantaneous observation results do not allow for separation of waves from water surface fluctuations caused by jets, making it difficult to grasp the direction and speed of the jet flow.

[0035] FIG. 4B is a diagram illustrating the effect of time-averaging radar observation results according to the embodiment. FIG. 4B illustrates the effect of averaging radar observation results obtained periodically. Because oceanic waves fluctuate periodically, averaging results in a nearly constant value. Therefore, the influence of oceanic waves can be eliminated by averaging radar images. Meanwhile, averaging the location of water surface fluctuations caused by jets clarifies the area where they occur. Furthermore, because this area moves downstream (moving together with the water mass) due to the flow of the jet, tracking its movement allows the direction and velocity of the jet to be determined. This is why vortices and other features are clearly visible. At the boundary between the jet and the seawater, a boundary corresponding to the tidal current may be visible. On the other hand, around the convergence zone (tidal current), the water surface becomes smooth due to divergence, reducing scattering, potentially making the trajectory of the jet more clearly visible on the radar image. Thus, averaging radar observation results makes it possible to identify areas with significant water surface disturbance (the area affected by the jet). In addition, since the turbulent area (water mass) is carried away by the flow of the discharged water, the direction and speed of the jet flow can be calculated by tracking the changes over time.

[0036] In order to average out waves and remove their effects, sufficient radar observations are required for the wave period (Tw). If the radar observation period is Tr and the number of observations is N, then the number of waves to be averaged will be Tr x N / Tw. In order to remove periodic fluctuations in waves, it is necessary that at least Tr x N > Tw / 2. In other words, the number of observations N must be N > 0.5 x Tw / Tr. If the radar observation period Tr is sufficiently small compared to the wave period Tw, averaging is possible even under conditions close to the minimum.

[0037] However, in reality, the wave period Tw is about 5 to 15 seconds. Furthermore, marine radar systems are rotary radar systems with rotating antennas, and the radar observation period Tr due to the rotation of the antenna is about 1 to 3 seconds. Therefore, Tw / 2 is an average of only a few observation results, and therefore cannot be used for sufficient averaging. Therefore, for example, in the case of a rotary radar system such as a marine radar system, an averaging time of about 30 seconds or more is appropriate.

[0038] On the other hand, a longer averaging time is more effective in clarifying the jet flow, but the longer the averaging time, the more the flow caused by the jet flow is averaged. Therefore, in order to confirm the jet flow phenomenon, it is necessary to set a short averaging time relative to the time change of the phenomenon.

[0039] The optimal averaging time for observing a jet depends on the flow velocity of the jet being observed, the rate of change in flow direction, and the phenomenon being observed. The inventors calculated average images by varying the averaging time used to calculate the average images and examined each average image. Figures 5A to 5G are diagrams showing examples of average images according to an embodiment. Figure 5A is an average image obtained when the averaging time was 10 seconds. Figure 5B is an average image obtained when the averaging time was 30 seconds. Figure 5C is an average image obtained when the averaging time was 1 minute. Figure 5D is an average image obtained when the averaging time was 5 minutes. Figure 5E is an average image obtained when the averaging time was 10 minutes. Figure 5F is an average image obtained when the averaging time was 15 minutes. Figure 5G is an average image obtained when the averaging time was 30 minutes.

[0040] After varying the averaging time, we found that an averaging time of 1 to 10 minutes is preferable. For example, as shown in Figures 5A and 5B, when the averaging time was set to 10 or 30 seconds, the image of the waves remained in the average image, making it difficult to distinguish between the image of the water surface fluctuations caused by the jet of warm water discharged from the outlet and the image of the waves. Furthermore, as shown in Figures 5F and 5G, when the averaging time was set to 15 or 30 minutes, the waves were averaged and the image of the waves disappeared in the average image, but the details of the jet became unclear, making analysis of the jet's behavior difficult. On the other hand, when the averaging time was set to 1, 5, or 10 minutes, as shown in Figures 5C-5E, the flow and vortices of the jet were visible in the average image, making it possible to analyze the jet's behavior.

[0041] Returning to FIG. 2, the calculation unit 41 calculates an average image by averaging the radar images represented by the data acquired by the acquisition unit 40 in the order of the observation time, for each averaging time set between 1 minute and 10 minutes. For example, the averaging time is set to 5 minutes. The calculation unit 41 reads out the radar images from the observation data 30 stored in the memory unit 23 in the order of the observation time, and calculates an average image by averaging each radar image during the 5-minute observation period every 5 minutes. By averaging the radar images in this way, the range of influence of the jet can be identified as an image in the average image.

[0042] The output unit 42 outputs information based on the average image calculated by the calculation unit 41. For example, the output unit 42 outputs the average image calculated by the calculation unit 41 to the display unit 22. The output unit 42 may output the data of the average image to the storage unit 23 for storage. The output unit 42 may also output the data of the average image to an external device.

[0043] The calculation unit 41 may further analyze the jet flow from the average image. For example, the calculation unit 41 may further calculate one or both of the flow direction and flow velocity of the jet flow by tracking the time change of the images of the sequentially calculated average images. The calculation unit 41 may also identify the range in the ocean where the jet flow flows from the sequentially obtained average images, thereby identifying the range of water temperature rise due to heated wastewater. The output unit 42 may output one or both of the flow direction and flow velocity of the jet flow and the identified range of water temperature rise to the display unit 22 as information based on the average image.

[0044] In this way, the observation device 12 acquires radar image data obtained by periodically observing the target sea area using the radar device 11, calculates an average image by averaging the radar images shown by the acquired data at predetermined averaging times in the order of observation time, and outputs information based on the calculated average image. This allows the observation device 12 to observe water surface fluctuations other than waves. In this embodiment, jets can be observed by observing water surface fluctuations other than waves. For example, at a power plant, an observer can use the observation device 12 to observe the jets of heated wastewater discharged from the discharge outlet, thereby estimating the range of water temperature rise caused by the heated wastewater. This allows the appropriate location of the discharge outlet to be determined. Furthermore, for example, if there is a strong concern that the range of water temperature rise caused by the heated wastewater will affect surrounding fishery resources or aquatic life, this can be used to determine whether the power generation capacity of the power plant should be adjusted to avoid such impacts.

[0045] [Processing flow] The flow of observation processing performed by the observation device 12 according to the embodiment will be described. Fig. 6 is a flowchart showing an example of the procedure of the observation processing according to the embodiment. This observation processing is executed at a predetermined timing, for example, at the timing when a predetermined operation is performed on the operation unit 21 to instruct the start of the observation processing.

[0046] The acquisition unit 40 acquires radar image data of the sea area to be observed periodically by the radar device 11 (step S10). For example, the acquisition unit 40 acquires the observation data from the radar device 11 or an external device that stores the observation data, and stores the acquired observation data in the storage unit 23 as observation data 30.

[0047] The calculation unit 41 calculates an average image by averaging the radar images indicated by the acquired data for each predetermined averaging time in the order of the observation times (step S11). For example, the calculation unit 41 reads out radar images from the observation data 30 stored in the storage unit 23 in the order of the observation times, and calculates an average image for each averaging time by averaging the radar images whose observation times fall within the averaging time.

[0048] The output unit 42 outputs information based on the calculated average image (step S12), and the process ends. For example, the output unit 42 outputs the average image calculated by the calculation unit 41 to the display unit 22.

[0049] [effect] In this way, the observation device 12 according to this embodiment acquires radar image data obtained by periodically observing the target sea area using the radar device 11. The observation device 12 calculates an average image by averaging the radar images shown by the acquired data at predetermined averaging times in the order of the observation times. The observation device 12 outputs information based on the calculated average image. This allows the observation device 12 to observe water surface fluctuations other than waves. In this embodiment, jets can be observed by observing water surface fluctuations other than waves.

[0050] The observation device 12 sets the averaging time to any time between 1 minute and 10 minutes. This allows the observation device 12 to obtain an image of water surface fluctuations that are different from waves while suppressing the influence of waves in the average image. In this embodiment, a clear image of the jet can be obtained.

[0051] The radar device 11 periodically observes the target sea area using radio waves of any of the X-band, C-band, S-band, and L-band, which allows the radar device 11 to detect the shape of the water surface caused by waves and jets, and obtain radar images that observe water surface fluctuations caused by waves and water surface fluctuations other than waves that are generated by jets.

[0052] The radar device 11 is a radar device for ships that uses radio waves in the X band or S band, which makes it possible to observe jets using a radar device for ships that is generally available.

[0053] The observation device 12 also outputs the average image. This allows the observation device 12 to observe water surface fluctuations different from ocean waves from the average image. In this embodiment, by observing water surface fluctuations different from ocean waves from the average image, it is possible to observe jets from the average image.

[0054] The observation device 12 also calculates one or both of the flow direction and flow velocity of the jet flow by tracking the time change in the area where scattering is obtained in the calculated average image. The observation device 12 outputs the calculated flow direction and flow velocity of the jet flow. This allows the observation device 12 to report the flow direction and flow velocity of the jet flow. [Example]

[0055] Although the embodiments of the disclosed device have been described above, the disclosed technology may be embodied in various different forms other than the above-described embodiments. Therefore, other embodiments included in the present invention will be described below.

[0056] For example, in the above embodiment, a case where the jet of heated wastewater discharged from the outlet of a power plant is observed by observing water surface fluctuations different from waves has been described as an example, but the disclosed device is not limited to this. The jet is not limited to heated wastewater, and wastewater of the same temperature as the sea area into which the water is discharged or of a lower temperature can be observed in the same way. Furthermore, the device is not limited to observing jets at power plants, and can be used to observe jets at various locations and facilities.

[0057] Furthermore, in the above-described embodiment, an example has been described in which a jet is observed by observing water surface fluctuations different from waves, but the disclosed device is not limited to this. For example, when volcanic gas is stored on the seabed, gas leakage can cause bubbles to form on the water surface, resulting in water surface fluctuations different from waves. The disclosed technology can also be applied to observing such water surface fluctuations. Similarly, in CCS (Carbon dioxide Capture and Storage), which stores carbon dioxide in geological layers, detecting gas leaks is also an issue. The disclosed technology can observe, for example, gas leaks on the seabed by observing water surface fluctuations different from waves.

[0058] In the above embodiment, the calculation unit 41 reads radar images from the observation data 30 in the order of observation time, and calculates an average image for each averaging time by averaging radar images whose observation times fall within the respective averaging times. However, the disclosed device is not limited to this. For example, the calculation unit 41 may calculate an average image by averaging radar images whose observation times fall within the averaging time from the start time while shifting the start time for calculating the average by a fixed amount for each radar image in the observation data 30. By setting the fixed amount of time shorter than the averaging time, the average image can be calculated by overlapping the averaging times. By consecutively displaying average images whose averaging times overlap, the changes in the jet flow can be displayed more smoothly.

[0059] As described above, the optimal averaging time for calculating the average image depends on the wave conditions, radar observation conditions, and jet conditions. In addition, the strength of wave scattering also has an effect. In other words, when scattering from open ocean waves is small to begin with (when waves are not very developed), the impact on the observation of water surface fluctuations other than waves, such as water surface fluctuations caused by jets, is small, so there is no need to set the averaging time long. When wave scattering is prominent, an appropriate averaging time must be set depending on the wave period. The calculation unit 41 may change the averaging time depending on the conditions of the sea area to be observed and the meteorological conditions at the time of observation. For example, the calculation unit 41 may lengthen the averaging time when wave scattering in the sea area to be observed is significant, and shorten the averaging time when wave scattering in the sea area to be observed is small. The calculation unit 41 may also acquire wind speed as a meteorological condition at the time of observation, and lengthen the averaging time when the wind speed is high, and shorten the averaging time when the wind speed is low. The averaging time may also be manually set externally, such as via the operation unit 21.

[0060] In the above embodiment, a jet flow is observed by the observation system 10, which is configured as a system including the radar device 11 and the observation device 12. However, the disclosed device is not limited to this. For example, the radar device 11 and the observation device 12 may be integrated into an observation device. In this case, the part corresponding to the radar device 11 corresponds to the acquisition unit of the present disclosure.

[0061] Furthermore, the components of each device shown in the figure are conceptual functional units and do not necessarily need to be physically configured as shown. In other words, the specific distribution and integration of each device is not limited to those shown in the figure, and all or part of the devices can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc. For example, the processing units of the acquisition unit 40, calculation unit 41, and output unit 42 may be integrated as appropriate. Furthermore, the processing of each processing unit may be separated into multiple processing units as appropriate. Furthermore, all or any part of the processing functions performed by each processing unit may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware using wired logic.

[0062] [Observation Program] The various processes described in the above embodiments can also be realized by executing a pre-prepared program on a computer system such as a personal computer or a workstation. Therefore, an example of a computer system that executes a program having the same functions as the above embodiments will be described below. Figure 7 is a diagram showing a computer that executes an observation program.

[0063] 7, the computer 300 includes a CPU (Central Processing Unit) 310, an HDD (Hard Disk Drive) 320, and a RAM (Random Access Memory) 340. These components 300 to 340 are connected via a bus 400.

[0064] The HDD 320 stores in advance an observation program 320a that performs the same functions as the acquisition unit 40, calculation unit 41, and output unit 42. Note that the observation program 320a may be separated as appropriate.

[0065] The HDD 320 also stores various types of information, such as the observation data 30 described above.

[0066] The CPU 310 then reads out and executes the observation program 320a from the HDD 320, thereby performing the same operations as the respective processing units in the embodiment. That is, the observation program 320a performs the same operations as the acquisition unit 40, the calculation unit 41, and the output unit 42.

[0067] It should be noted that the above-described observation program 320a does not necessarily need to be stored in the HDD 320 from the beginning.

[0068] For example, the program may be stored on a "portable physical medium" such as a flexible disk (FD), CD-ROM, DVD disk, magneto-optical disk, or IC card that is inserted into computer 300. Then, computer 300 may read and execute the program from these.

[0069] Furthermore, the program may be stored in "another computer (or server)" connected to the computer 300 via a public line, the Internet, a LAN, a WAN, etc. The computer 300 may then read and execute the program from the other computer (or server). [Explanation of symbols]

[0070] 10 Observation System 11 Radar equipment 12 Observation equipment 20 External interface section 21 Control section 22 Display section 23 Memory section 24 Control Unit 30 Observation data 40 Acquisition Department 41 Calculation section 42 Output section

Claims

1. Obtain radar image data by periodically observing the target sea area using a radar device that uses radio waves with wavelengths of 0.01 m to 2 m, Calculating an average image by averaging the radar images represented by the acquired data for each averaging time set between 1 minute and 10 minutes in the order of observation time; calculating one or both of the flow direction and flow velocity of the jet by tracking the time change of the area where scattering is obtained in the calculated average image; Outputting either or both of the calculated flow direction and flow velocity of the jet An observation program that causes a computer to execute processing.

2. Obtain radar image data by periodically observing the target sea area using a radar device that uses radio waves with wavelengths of 0.01 m to 2 m, The averaging time is changed between 1 minute and 10 minutes depending on the state of the sea area to be observed and the weather conditions at the time of observation, and an average image is calculated by averaging the radar images shown by the acquired data for each averaging time in the order of observation time; Output information based on the calculated average image. An observation program that causes a computer to execute processing.

3. The radar device periodically observes the target sea area using radio waves of any one of X-band, C-band, S-band, and L-band.

3. The observation program according to claim 1 or 2.

4. The radar device is a radar device for ships that uses radio waves in the X band or S band.

3. The observation program according to claim 1 or 2.

5. The output process outputs the average image.

5. The observation program according to claim 1, wherein the observation program is a program for performing an observation on a computer.

6. Obtain radar image data by periodically observing the target sea area using a radar device that uses radio waves with wavelengths of 0.01 m to 2 m, Calculating an average image by averaging the radar images represented by the acquired data for each averaging time set between 1 minute and 10 minutes in the order of observation time; calculating one or both of the flow direction and flow velocity of the jet by tracking the time change of the area where scattering is obtained in the calculated average image; Outputting either or both of the calculated flow direction and flow velocity of the jet An observation method characterized in that processing is performed by a computer.

7. Obtain radar image data by periodically observing the target sea area using a radar device that uses radio waves with wavelengths of 0.01 m to 2 m, The averaging time is changed between 1 minute and 10 minutes depending on the state of the sea area to be observed and the weather conditions at the time of observation, and an average image is calculated by averaging the radar images shown by the acquired data for each averaging time in the order of observation time; Output information based on the calculated average image. An observation method characterized in that processing is performed by a computer.

8. an acquisition unit that acquires radar image data obtained by periodically observing a target sea area using a radar device that uses radio waves with a wavelength of 0.01 m to 2 m; a calculation unit that calculates an average image by averaging radar images represented by the data acquired by the acquisition unit for an averaging time set between 1 minute and 10 minutes in the order of observation time, and tracks the time change of an area where scattering is obtained in the calculated average image, thereby calculating one or both of the flow direction and flow velocity of the jet; an output unit that outputs one or both of the flow direction and flow velocity of the jet calculated by the calculation unit; An observation device comprising:

9. an acquisition unit that acquires radar image data obtained by periodically observing a target sea area using a radar device that uses radio waves with a wavelength of 0.01 m to 2 m; a calculation unit that changes the averaging time between 1 minute and 10 minutes depending on the state of the sea area to be observed and the weather conditions at the time of observation, and calculates an average image by averaging the radar images indicated by the data acquired by the acquisition unit for each averaging time in the order of the observation times; an output unit that outputs information based on the average image calculated by the calculation unit; An observation device comprising:

10. a radar device that periodically observes using radio waves with wavelengths of 0.01 m to 2 m and generates data of the observed radar image; an observation device having an acquisition unit that acquires radar image data obtained by periodically observing the sea area to be observed using the radar device; a calculation unit that calculates an average image by averaging the radar images shown by the data acquired by the acquisition unit for an averaging time set between 1 minute and 10 minutes in the order of observation time, and calculates one or both of the flow direction and flow velocity of the jet flow by tracking the time change of the area where scattering is obtained in the calculated average image; and an output unit that outputs one or both of the flow direction and flow velocity of the jet flow calculated by the calculation unit; An observation system comprising:

11. a radar device that periodically observes using radio waves with wavelengths of 0.01 m to 2 m and generates data of the observed radar image; an observation device having an acquisition unit that acquires radar image data obtained by periodically observing the sea area to be observed using the radar device; a calculation unit that changes the averaging time between 1 minute and 10 minutes depending on the state of the sea area to be observed and the weather conditions at the time of observation, and calculates an average image by averaging the radar images shown by the data acquired by the acquisition unit for each averaging time in the order of the observation time; and an output unit that outputs information based on the average image calculated by the calculation unit; An observation system comprising:

Images