A method and medium for determining the window period for ship entry and exit under real-time tidal utility

Abstract

The present invention relates to a method and medium for determining a ship's port entry and exit window period under real-time tidal utility. The method comprises the following steps: based on tidal table data published by tidal observation points at the port, obtaining tidal current vectors at each tidal observation point in the time dimension through preprocessing, obtaining tidal current prediction data in the time and space dimensions through interpolation, wherein the tidal current prediction data includes information on tide height, tidal current magnitude, and tidal current direction at different times and spatial locations; obtaining port entry and exit window period information for ships based on the tidal current prediction data; and obtaining a visualization signal based on the port entry and exit window period information. Compared with the prior art, the present invention has the advantages of high tidal current data accuracy, comprehensive data, strong guidance for navigation practice, and the ability to effectively improve navigation efficiency.

Description

Technical Field

[0001] The present invention relates to the field of tide prediction, and in particular to a method and medium for determining a window period for ship entry and exit under real-time tidal utility. Background Art

[0002] Ships' port entry and exit are influenced by numerous factors, particularly environmental information. The optimal port entry and exit window depends on accurate, real-time, and comprehensive environmental data. Natural conditions such as weather and sea conditions place significant demands on information, including wind, current, waves, visibility, and tides. Tidal information displayed on ship-mounted tide tables is based on annual tidal forecasts derived from harmonic analysis or fitting of long-term field data from permanent coastal tidal observatories. Clearly, these tables fail to reflect non-periodic, time-varying factors, leading to significant forecast errors, particularly when hydrometeorological factors fluctuate dramatically. To mitigate the limitations of low tidal prediction accuracy based on these methods or models, navigational practice often uses correlation between tidal data from the projected ship's position and tidal observation points to extrapolate tidal data, thereby obtaining channel depth information that accounts for tidal height. This empirical approach, based on harmonic analysis, also suffers from a relatively high degree of inaccuracy because it fails to account for the influence of hydrometeorological and other factors on tides. Some ships, based on operational needs, temporarily observe tidal data at a target location, along with tidal and hydrometeorological data from other nearby locations, and then perform tidal fitting at the target location. However, for tidal ports with long waterways, a single vessel cannot achieve real-time tidal data fitting using multi-source data acquisition equipment.

[0003] The core technology underlying these methods is ocean current models, which offer high accuracy but also come at a high cost. Using tidal data periodically released by ocean authorities for tidal prediction and decision-making support is a relatively cost-effective and convenient method, using visualization techniques and methods such as GIS, MSchart controls, Matlab tools, and inverse square spatial interpolation. However, because tidal data from tidal observatories are spatially discrete, current tidal data at different moments is often derived from the temporal continuity of the tide, with less attention paid to the spatial continuity of tidal direction and magnitude. Given the busy waterway traffic, utilizing a single tidal window for ship entry and exit operations is increasingly difficult to meet the growing trend of port automation and larger ships. The long waterway and the seabed topography nearby vary widely, and tidal and tidal information is complex, necessitating the precise definition of entry and exit restrictions based on minimum tidal height limits and maximum tidal current limits. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a method and medium for determining the window period for ship entry and exit under real-time tidal effect, so as to realize the determination of the window period for ship entry and exit based on observation data of limited tidal observation points.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention provides a method for determining a ship entry and exit window period under real-time tidal utility, comprising the following steps:

[0007] Based on the tide table data of the port's tide observation points, the tidal vector of each tidal observation point in the time dimension is obtained through preprocessing, and the tidal forecast data in the time dimension and space dimension are obtained through interpolation, wherein the tidal forecast data includes the tidal height, tidal magnitude and tidal direction information at different times and different spatial locations;

[0008] Based on the tide prediction data, obtaining the ship's port entry and exit window information;

[0009] Based on the entry and exit window information, a visualization signal is obtained.

[0010] As a preferred technical solution, the acquisition of the tidal vector of each tidal observation point in the time dimension includes the following steps:

[0011] The time-discrete tidal flow data of each tidal observation point are obtained, and the time-continuous tidal flow vector of each tidal observation point is obtained through interpolation and approximate differentiation.

[0012] As a preferred technical solution, obtaining the power flow prediction data in the time dimension and the space dimension by interpolation specifically includes the following steps:

[0013] The coordinate information of the tidal observation point and several unknown points in the port is obtained. Based on the coordinate information and the tidal vector of each tidal observation point in the time dimension, the tidal data at different spatial positions at the same time are obtained through primary interpolation for estimation, and the tidal estimation data at different spatial positions at different times are obtained through secondary interpolation.

[0014] As a preferred technical solution, the unknown point is on the route of the port.

[0015] As a preferred technical solution, the primary interpolation is Kriging interpolation.

[0016] As a preferred technical solution, the primary interpolation is implemented using the following formula:

[0017]

[0018] Where, is the estimated value at point (x0, y0), n represents the number of tidal observation points, w i represents the weight coefficient of the i-th tidal observation point, z i represents the observation value of the i-th tidal observation point, and satisfies E() means expected value, min() means minimum value, and Var() means variance.

[0019] As a preferred technical solution, the acquisition of the entry and exit window period information includes the following steps:

[0020] Based on the tide prediction data, the entry and exit period status indicators of different spatial positions in the port are determined, and the corresponding navigation window period is determined based on the exit period status indicators to obtain the entry and exit window period information.

[0021] As a preferred technical solution, periodic visualization is achieved through contour line and time series processing within a preset time step.

[0022] As a preferred technical solution, the entry and exit status indicators are initial rise, rapid rise, initial fall, rapid fall and final fall.

[0023] As a preferred technical solution, the process of obtaining a visual signal includes the following steps:

[0024] The length of the arrow is used to represent the magnitude of the tidal velocity, the direction of the arrow is used to represent the tidal flow direction, different colors are used to represent different tidal heights, and the visualization signal is output.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) The tidal data is highly accurate and comprehensive, and has strong guidance for navigation practice, which can effectively improve navigation efficiency: The present invention first obtains tidal information from a limited number of tidal observation stations, and interpolates the original sparse data area into high-resolution grid data through the interpolation method, and obtains tidal prediction data that is approximately continuous in time and space, thereby improving the resolution and accuracy of the data. At the same time, it can reduce the error in the original spatial data to a certain extent, thereby improving the reliability and accuracy of the data, and realizing the effective conversion of tidal table data into multidimensional data. Based on the tidal prediction data, the port departure window period is determined and visualized, which is convenient for front-line captains and pilots to accurately judge the tide height and tidal information during navigation, and then decide on the port entry tidal window, providing technical support for ship navigation risk prevention and traffic organization guarantee, and improving port production efficiency.

[0027] (2) Optimized the real-time sensing of tides in different spaces: For tidal current data, tidal current data at fixed points can only be obtained from certain observation stations. In order to solve the problem of missing data on continuous planes under a certain water area, the Kriging spatial interpolation algorithm is used to repair the missing data. The tidal algorithm is further combined with visualization mathematical tools to enable the simultaneous presentation of multi-dimensional tidal current data at different geographical locations in the entire space. The Kriging interpolation method, which can take into account both spatial position and correlation, is used to reduce spatial data errors on the basis of repairing the missing spatial data. The tidal algorithm and visualization technology are integrated to simultaneously present multi-dimensional tidal current data at different geographical locations in the entire space, realize the visualization of tidal currents in different spaces under time series, and further realize the dynamic and differentiated perception of real-time tidal information. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of the method for determining the window period for ship entry and exit under the real-time tidal utility in Example 1;

[0029] Figure 2 A scenario description and model application diagram for ships entering and leaving the tidal port window period;

[0030] Figure 3 This is the Shanghai Port tide rising and falling time-sharing chart;

[0031] Figure 4 This is a time-sharing chart of the Shanghai Port tide rising first and then falling;

[0032] Figure 5 Schematic diagram of tide height and tidal flow direction at tide measuring points. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0034] Example 1

[0035] In response to the increasing demands for real-time and comprehensive port entry and exit operations, the present invention provides a method for determining the port entry and exit window period using real-time tidal data. This method aims to provide more comprehensive and real-time tidal data, such as tide heights and currents, for ships entering and leaving the port in both temporal and spatial dimensions. This facilitates frontline captains and pilots to accurately assess tide heights and currents during navigation, enabling them to determine the appropriate tidal window for port entry. This method provides technical support for shipowners to mitigate navigation risks and ensure traffic organization, thereby improving port production efficiency.

[0036] Tidal currents and tidal data are inextricably linked. Therefore, visualization technology can be used to present historical information such as tide times, tide heights, and tidal currents contained in tide tables, enabling forecasts of offshore tidal currents. This forecasting method provides accurate data and information, helping people better understand the changing trends of offshore tidal currents and make better decisions.

[0037] This embodiment establishes a rasterized visualization platform for static data of tides and tidal currents and adopts a three-dimensional interpolation algorithm to achieve continuous dynamic presentation of the actual conditions and trends of tide heights and tidal currents in both time and space dimensions. It deeply associates the navigation process of ships with the tide and tidal current conditions of the scene, integrates the characteristics of ships with the water depth information of nautical charts, and optimizes the analysis of the navigation window period for ships entering and leaving the port under the dual constraints of tide heights and tidal currents.

[0038] This method first collects tidal height, current, and ship route coordinate data for the studied waters. Tidal height and current data for different spatial and temporal locations in the studied waters are obtained from tidal tables at port tidal observatories. This data is then preprocessed to remove missing data and outliers. A three-dimensional Kriging interpolation algorithm is then used to visualize the port waters' currents and routes in both time and space. This allows for real-time analysis of the currents affecting ships entering and leaving the port, optimizing the ship's operating window.

[0039] like Figure 1 The flowchart of the method includes the following steps:

[0040] Step S1: Acquisition of original data of tides and routes. Obtain original data related to tide height and flow velocity from the tide observation table. At the same time, extract the coordinate data of the main channel of the studied waters based on Matlab software, and complete the visualization of the channel and the studied waters.

[0041] Step S2: Assuming that the tide in the studied waters is a reciprocating flow, the tide direction measured from the tide observation station is only two: rising tide and falling tide. Obtain the tide height data in different time dimensions from the tide table of the port tide observation station, such as Figure 4 As shown in Figure 2. Combining the two-dimensional interpolation algorithm and the approximate differential algorithm, the tidal current data in the corresponding time dimension can be calculated based on the tidal height data in different time dimensions obtained from different tide measuring stations. That is, the tidal current vector data in different time dimensions of each tide measuring station can be calculated using formulas (1)-(4).

[0042]

[0043] v y =v·sinα (2)

[0044] v x =v·cosα (3)

[0045]

[0046] Where: Δt- is the time interval; v- is the instantaneous speed of the tidal current; v x - is the horizontal component of the instantaneous velocity of the tidal current; v y - is the vertical component of the instantaneous velocity of the tidal current, that is, the change in tidal height within Δt.

[0047] Step 3: According to the core idea of ​​the Kriging interpolation algorithm, the difference in the attribute values ​​of two points is positively correlated with the distance between them within a certain distance range, and can be derived from the positions and attribute values ​​of a certain number of surrounding points. Therefore, the tide height data obtained from a limited number of known observation points and the calculated flow direction and velocity data can be used to realize the tidal conditions of the entire area of ​​the studied waters, namely the values ​​of tide height data, flow direction, and flow velocity data. For a number of known discrete points (x i ,y i ) is the observed value z of an attribute i =z(x i ,y i ) under the condition of estimating the attribute value of any point (x,y) in space. Its expression is:

[0048]

[0049] Where, is the estimated value at point (x0,y0), that is w i Represents the weight coefficient, using the weighted sum of all known points to estimate the unknown point; z i Represents a known point (x i ,y i ) observations.

[0050] w i Requires the estimated value at point (x0, y0) to be satisfied The difference with the true value z0 is the smallest

[0051]

[0052] At the same time, we hope to estimate The variance of the difference from the true value z0 is minimized

[0053]

[0054] In addition, a stable space is required, that is, the value z=z(x,y) at any point in the space is composed of the regional average C and the random deviation R(x,y), where the variance of the deviation is a constant

[0055] z(x,y)=R(x,y)+C (8)

[0056] Var[R(x,y)]=σ 2 (9)

[0057] Written in the expected form

[0058] E(z)=C (10)

[0059] Kriging interpolation allows predictions to be made based on existing spatial data without the need to collect large amounts of data across the entire region, significantly reducing the cost and time of data collection. It also allows the use of known spatial data points to infer values ​​at unknown locations, interpolating areas with sparse data into high-resolution grid data to improve data resolution and accuracy. Interpolation can also reduce errors in the original spatial data to a certain extent, thereby improving data reliability and accuracy.

[0060] Step S4, based on the principle of four-dimensional interpolation algorithm, interpolate the tide height (tidal current) data of multiple tide measuring stations in the spatial dimension to obtain the tide height (tidal current) data of continuous space at different times, use the four-dimensional interpolation algorithm to interpolate the tide height (tidal current) data in the time dimension to obtain the tide height (tidal current) data of continuous time in continuous space, and then visualize the tide height (tidal current) data.

[0061] Based on the principle of a four-dimensional interpolation algorithm, tidal height (current) data from multiple tide measuring stations are interpolated in the spatial dimension to obtain tidal height (current) data at different times in continuous space. This tidal height (current) data is then interpolated in the temporal dimension using a four-dimensional interpolation algorithm to obtain tidal height (current) data at continuous time in continuous space. This tidal height (current) data is then visualized. The magnitude of the tidal flow velocity is represented by the length of the arrow, the flow direction is represented by the direction of the arrow, and the magnitude of the tidal height data is represented by changes in color, thus achieving visualization of the tidal height and tidal flow (flow direction and velocity) in the studied waters.

[0062] Step S5 combines the ship's arrival and departure process with real-time tidal changes to analyze the dynamic changes in tide height and current at different times and locations along the route during the navigation window. For tides in different time dimensions, mathematical algorithms, contour lines, and time series are introduced, using a set period as a time step, to present a visual animation of the cyclical changes in tidal data in the target sea area.

[0063] Step S6: There are many factors that affect the navigation window for ships, among which tide and water depth are the key factors in determining the navigation window for ships. Analyzing the water depth and tidal conditions during the ship's navigation process in different time and space dimensions is of great significance for optimizing the navigation window for ships. The navigation window for ships can be divided into different types, such as initial rise, rapid rise, end of rise, initial fall, rapid fall, and end of fall. During initial rise and rapid rise, the water level is low and the navigation window is short, so ships need to pass through the channel in a short time. At the end of rise and end of fall, the water level is high and the navigation window is also short, so ships also need to seize the time to pass through the channel. During initial fall and rapid fall, the water level gradually decreases, the navigation window is longer, and ships can navigate for a longer time. Based on real-time tidal data, ships can perform real-time sensing and then determine the navigation window for ships, realizing the optimization of the window efficiency under the tidal effect of tidal ports. This can more accurately determine the navigation time and improve navigation efficiency and safety.

[0064] Figure 2 (a) shows the water conditions of the Yangtze River Estuary in Shanghai Port and the location distribution of some tide gauges. (b) shows the temporal and spatial analysis of the tidal conditions of the selected route, where the horizontal axis is continuous time and the vertical axis is the distance of the route point relative to the dock. (c) shows the tidal distribution at different port entry times, analyzing the tidal conditions experienced by ships during high and low tide operations. The horizontal axis is time and the vertical axis is the distance of the route point relative to the dock. (d) shows a three-dimensional visualization of the temporal trend of the tidal height at a certain distance from the dock, where the X-axis and Y-axis represent the distance and time relative to the dock, respectively, and the Z-axis represents the tidal height. In (c) and (f), the vertical axis is the distance of the route point relative to the dock, and the horizontal axis is the tidal time. The ship's entry process curve is drawn based on the departure time and speed of the ship entering the port.

[0065] In addition, when both high and low tides meet the water depth requirements of ships, the ships will be less affected by the current during the entire process of entering the port, and the high (low) low tide curves between adjacent high (low) low tides are used as the port entry window. According to the tidal height visualization diagram, it can be seen that two high tides and two low tides occur in one tidal cycle, so the navigation time of the ship can be determined by combining the speed, and the route status diagram of the ship during low tide and high tide can be drawn to obtain Figure 2 Visualization of the coordinates of the ship’s entry position as shown by the blue lines in (c) and (f).

[0066] The tidal data of 14 tide measuring stations in the waters of Shanghai Port are visualized. The tidal data of July 1, 2023 in the Tide Table are collected, and the discontinuous tidal height and tidal flow data in the time and space dimensions are obtained through simple calculations of formulas 1-4. The tidal height and tidal flow data of the 14 tide measuring stations are interpolated in the spatial dimension to obtain the tidal height and tidal flow data of the continuous space of the Shanghai Port area at different times. The Kriging interpolation algorithm is used to interpolate the tidal height and tidal flow data in the time dimension again to obtain the tidal height and tidal flow data of continuous time in different spaces, and then the visualization effect of the continuous tidal height and tidal flow in the dual dimensions of time and space is obtained. The results are as follows: Figure 3-4 Shown are the hourly tide heights and tidal conditions on the first day of the seventh lunar month. Figure 3 In the figure, (a) to (l) are schematic diagrams of the tidal conditions for each hour from 00:00 to 11:00 on the first day of July. Figure 4 (a) to (l) are schematic diagrams of the hourly tide conditions from 07:00 to 14:00 on July 1, respectively.

[0067] Combined with the spatial distribution of water depths in the Shanghai Port area chart, an analysis was conducted from the perspective of the window period under the requirements of water depth and tide. Taking the entry and exit of large containers in and out of the Waigaoqiao Terminal of Shanghai Port as an example, with the entrance and exit of the channel near the Waigaoqiao Terminal and Jigujiao as the starting point, and the Beicao waterway of the Yangtze River Estuary as the planned route, the empirical time for the entry and exit, berthing and unberthing process is 4.5 hours. The lowest water depth of the Beicao waterway chart is 12.5 meters (the tide height datum is the chart datum), and the ship is required to have a surplus water depth of 12% of the ship's draft during navigation in the port area. During the period when the ship enters the port and berths, on the premise of meeting the safe water depth, the tide is required to be as small as possible during berthing, and the ship should sail downstream as much as possible during the entry into the port to reduce energy consumption.

[0068] Based on the waterway chart, which shows a minimum depth of 12.5 meters and a port entry time of 4 hours, the maximum draft for ships entering the port on July 1st is 13.1 meters. The port entry window is from 10:20 to 14:20. During this time, the maximum downstream current is approximately 0.83 m / s, and the tidal current at the berth is open current at 0.16 m / s. If a ship's draft is 12.5 meters, which requires a waterway depth of 14 meters, the port entry window on July 1st is from 00:00 to 04:10 and 09:00 to 16:10. The maximum ebb tide velocity during 00:00 to 04:10 is 0.75 m / s, and the maximum high tide velocity during 09:00 to 16:10 is 0.99 m / s, with the maximum ebb tide velocity reaching 0.72 m / s.

[0069] Similarly, when leaving the port, ships should sail downstream whenever possible while meeting safe water depth requirements. Data analysis shows that the low tide windows on the first day of July are 00:00-08:00 and 12:00-19:00, with the lowest water depth in the North Trough at 13.6 meters. If ships are required to sail downstream throughout the entire journey, the optimal windows are 00:00-04:00 and 12:00-16:00, allowing for maximum drafts of 12.61 meters and 12.67 meters, respectively, and maximum downstream currents of 0.75 m / s and 0.72 m / s, respectively.

[0070] The present invention has the following beneficial effects:

[0071] 1. The effective conversion of tide table data into multi-dimensional data is achieved. By analyzing the tide height information of each tide measuring station, mathematical modeling and nonlinear fitting are performed, and finally the real-time tide height data, tidal flow velocity data, tidal flow direction data, etc. of the entire port water area are obtained. Through the interpolation method, the area with sparse data is interpolated into high-resolution grid data, thereby improving the resolution and accuracy of the data. At the same time, the error in the original spatial data can be reduced to a certain extent, thereby improving the reliability and accuracy of the data. With the help of visualization tools, the temporal and spatial data are continuous, and comprehensive information on tides (tidal heights and tidal currents) in the entire area and multiple time periods is obtained.

[0072] 2. Route-based real-time tidal sensing for ships entering and leaving ports. This system combines the port entry and exit process with tidal changes to dynamically present tide height and tidal current data, revealing the spatiotemporal consistency of the dynamic changes in tide height and tidal current at various time points along the route during the six tidal windows. Using a set period as a time step, mathematical algorithms, contour lines, and time series are introduced to visualize tidal data in the target sea area in a periodic manner.

[0073] 3. Optimizing the ship entry and exit window period considering tidal effects. Tidal magnitude and direction affect bow stability and ship attitude control during navigation. This study examines ship navigation processes in different temporal and spatial dimensions, presenting real-time tidal sensing during different window periods: initial surge, rapid surge, final surge, initial decline, rapid decline, and final decline. Based on the ship's entry and exit speed and duration, this study optimizes the efficiency of these window periods within the tidal effect of tidal ports, ensuring overall ship safety.

[0074] Example 2

[0075] This embodiment provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs include instructions for executing the method for determining the ship entry and exit window period under the real-time tidal utility as described in Example 1.

[0076] Example 3

[0077] This embodiment provides a computer-readable storage medium, including one or more programs for execution by one or more processors of an electronic device, wherein the one or more programs include instructions for executing the method for determining the window period for ship entry and exit under real-time tidal utility as described in Example 1.

[0078] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for determining the window period for ships entering and leaving a port under real-time tidal utility, characterized in that: The steps include: Based on the tide table data of the port's tide observation points, the tidal vector of each tidal observation point in the time dimension is obtained through preprocessing, and the tidal forecast data in the time dimension and space dimension are obtained through interpolation, wherein the tidal forecast data includes the tidal height, tidal magnitude and tidal direction information at different times and different spatial locations; Based on the tide prediction data, obtaining the ship's port entry and exit window information; Based on the entry and exit window information, a visual signal is obtained. Obtaining power flow prediction data in the time and space dimensions through interpolation specifically includes the following steps: The coordinate information of the tidal observation point and several unknown points in the port is obtained. Based on the coordinate information and the tidal vector of each tidal observation point in the time dimension, the tidal data at different spatial positions at the same time are obtained through primary interpolation for estimation, and the tidal estimation data at different spatial positions at different times are obtained through secondary interpolation.

2. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: The acquisition of the tidal vector at each tidal observation point in the time dimension includes the following steps: The time-discrete tidal flow data of each tidal observation point are obtained, and the time-continuous tidal flow vector of each tidal observation point is obtained through interpolation and approximate differentiation.

3. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: The unknown point is on the route to the port.

4. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: The primary interpolation is implemented using the following formula: Where, is the estimated value at point (x0, y0), n represents the number of tidal observation points, w i represents the weight coefficient of the i-th tidal observation point, z i represents the observation value of the i-th tidal observation point, and satisfies E() means expected value, min() means minimum value, and Var() means variance.

5. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: The acquisition of the entry and exit window period information includes the following steps: Based on the tide prediction data, the entry and exit period status indicators of different spatial positions in the port are determined, and the corresponding navigation window period is determined based on the exit period status indicators to obtain the entry and exit window period information.

6. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 5 is characterized in that: The entry and exit status indicators are initial rise, rapid rise, end of rise, initial fall, rapid fall and end of fall.

7. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: Within the preset time step, periodic visualization is achieved through contour lines and time series processing.

8. The method for determining the window period for ship entry and exit under real-time tidal effect according to claim 1 is characterized in that: The process of obtaining a visual signal includes the following steps: The length of the arrow is used to represent the magnitude of the tidal velocity, the direction of the arrow is used to represent the tidal flow direction, different colors are used to represent different tidal heights, and the visualization signal is output.

9. A computer-readable storage medium, characterized in that It includes one or more programs for execution by one or more processors of an electronic device, and the one or more programs include instructions for executing the method for determining the window period for ship entry and exit under real-time tidal utility as described in any one of claims 1-8.

Images