Visual display and maintenance method and system for ship navigation warning

Abstract

The invention relates to the technical field of front-end visualization, in particular to a ship navigation warning visual display and maintenance method and system. The method comprises the following steps: collecting, sorting and maintaining navigation warning data, drawing the obtained navigation warning data on a map by adopting different graphs for visual display, monitoring scaling and magnifying events of a map proportion level, and performing aggregation and aggregation separation display on center point marks according to the monitored events. The system comprises a data collection module, a data maintenance module, a data display module and a data monitoring module. The navigation warning data are drawn on a map by adopting different graphs to be visually displayed, so that a user can visually and quickly check all the navigation warning data, and the problem that at present, after receiving the navigation warning, a ship party needs to search on the map one by one according to the position and the area of the navigation warning; and a large amount of time needs to be consumed.

Description

Technical Field

[0001] The present invention relates to the field of front-end visualization technology, and in particular to a method and system for visualizing and displaying and maintaining ship navigation warnings. Background Art

[0002] Navigation warning is a kind of announcement issued by maritime agencies according to national regulations by radio. It notifies all ships promptly and accurately by radio of any environmental changes that may affect the safety of navigation and operation in the relevant sea areas and waters, so that they can take appropriate measures or remain alert to ensure the safety of navigation and operation. It is a supplement to navigation notices. Navigation warnings can be divided into regional warnings, coastal warnings and local warnings according to the distribution range and function; in regional warnings, the relevant countries and regions of each navigation warning area jointly negotiate to determine a regional coordinator, who is responsible for collecting, checking, collating and editing, and then broadcasting the navigation warnings for the entire jurisdiction, and the language used is generally the official language of the United Nations; in coastal warnings, each coastal country in each region determines an agency as a national coordinator, who is responsible for collecting, checking, collating and broadcasting navigation warnings for its own country and neighboring coastal waters, and quickly transmits relevant information to the coordinator of the region; local warnings are navigation warnings issued by the port authorities that do not exceed the scope of the waters under their jurisdiction.

[0003] Navigation warnings are broadcast by the port supervisor through the port radio station. Ship radio stations should listen to the call signs, frequencies and broadcast times of the coastal radio stations distributed in the navigation area. The port supervisor should inform the ship of the important contents of recent navigation warnings such as waterways, navigation marks, buoys, sunken objects, etc. according to the ship's requirements to ensure navigation safety. However, in actual navigation, the ship will receive a large number of navigation warnings, and the ship needs to parse and process the navigation warnings one by one. The existing navigation warnings mainly represent the problems in a certain location or area in the form of data. The ship needs to search one by one on the map according to the location and area of ​​the navigation warning, which is not intuitive and takes a lot of time. Summary of the invention

[0004] The present invention solves the problem that after receiving a navigation warning, the ship needs to search one by one on the map according to the location and area of ​​the navigation warning, which is not intuitive and takes a lot of time. A method and system for visual display and maintenance of ship navigation warnings are provided, which collects, organizes and maintains navigation warnings issued by maritime agencies around the world and displays them on maps, making it convenient for users to intuitively and quickly view and process navigation warnings.

[0005] The technical solution claimed in the present invention is as follows:

[0006] A method for visualizing and maintaining ship navigation warnings, comprising the following steps:

[0007] S1: Data collection and organization: Collect navigation warning data released by maritime administrations around the world, and classify, summarize, and organize it according to data characteristics; the navigation warning data is real-time navigation warnings released by maritime administrations around the world.

[0008] S2: Data maintenance: Automatically parse the data obtained in S1 and display it in the form of a navigation warning list, and support manual editing, deletion, and addition operations for each piece of navigation warning data displayed.

[0009] S3: Data display: The navigation warning data obtained in S2 is visualized by being plotted on a map in different graphical forms; the map simultaneously plots two map copies on the left and right; each of the different graphics corresponds to a center point marker, and the center point marker is also plotted on the map.

[0010] S4: Monitor the zoom-in and zoom-out events of the map scale level in S3, and perform aggregation and aggregation separation display on the center point markers according to the monitored events.

[0011] In a specific embodiment of the present invention, the data characteristics in S1 include: warning area type, center point of the warning area, longitude and latitude of the warning area, warning title, warning details, release date.

[0012] Preferably, in S2, the data obtained in S1 is automatically parsed through a web page and displayed in the form of a navigation warning list, and each navigation warning displayed in the navigation warning list includes an icon indicating whether the data has been confirmed.

[0013] Preferably, the map in S3 is a web map, and the web map is displayed in the form of the different graphics based on Leaflet map, including: points, multi-points, lines, polygons, circles, sectors; the center point marker corresponding to the point is the current point; the center point marker corresponding to the multi-points is the center point calculated from the coordinates of these points; the center point markers of the line, polygon, circle, and sector are the center points of the corresponding graphics; for the center point outside the polygon, the center point is adjusted, and the adjustment method is: use the centroid to replace the center point, the polygon is divided into multiple simple graphics, and the centroid coordinates of the polygon are G(x,y), and the calculation formulas for x and y are:

[0014]

[0015] where n is the number of simple graphics, S i is the area of the i-th simple graphic, G ix is the x coordinate of the centroid of the i-th graphic, G iy is the y coordinate of the centroid of the i-th graphic; x and y are obtained through the above formulas, and G(x,y) is the centroid coordinates of the graphic.

[0016] Preferably, the map in S3 supports pop-up windows. When the mouse moves to the center point marker, a pop-up window that displays the current navigation warning content will automatically pop up. When the mouse moves away from the center point marker, the pop-up window will automatically disappear.

[0017] S3 includes the processing of the pop-up window. The specific steps include:

[0018] Step 1: Set a custom className when creating the center point marker corresponding to the navigation warning data.

[0019] Step 2: Rotate all pop-up window directions by 180 degrees in the style file so that they default to downward.

[0020] Step 3: When drawing the center point marker corresponding to each navigation warning data, judge its latitude. When the latitude is less than -35 degrees, obtain the current dom element through marker._popup.getElement(), and set the transform property of the style of this dom element to rotate(0deg) so that the window pop-up direction is upward.

[0021] The map in S3 sorts out the aviation warning data across 180 degrees. The sorting method is to adjust the longitude of the warning area in the aviation warning data. The adjustment formula is as follows:

[0022]

[0023] Where: The source data of longitude and latitude is an array, x i is the i-th longitude in the longitude and latitude array; c is the offset, starting from c = 0; y i is the longitude calculated by f(x i ); x i+1 represents the (i + 1)-th longitude in the longitude and latitude array; y i+1 is the longitude calculated by f(x i+1 ); c * y i is the converted longitude; f(x i , c) means starting from the i-th longitude in the longitude and latitude array and traversing for calculation, with the offset c starting from zero; f(x i ) means pushing to the y i value during the conditional traversal process, |x i - x i+1 | > 180, that is, when the absolute value of the difference between the (i + 1)-th longitude and the i-th longitude is greater than 180 degrees, return y i , or until the last data is traversed and there is no data that meets this condition, then assign x i to y i ; f(c, y i) indicates internal continuous traversal starting from zero. According to f(x i ) the obtained y i value, y i+1 is the value obtained from f(x i+1 ). When y i ≤ 0 ∪ y i+1 ≥ 0, the offset c is incremented by 1. When y i ≥ 0 ∪ y i+1 ≤ 0, the offset c is decremented by 1. When the traversal of the entire longitude and latitude array is completed, the final offset c and y i are derived and calculated. Their product is the finally obtained correct longitude.

[0024] The aggregation described in S4 means that when the map scale level is reduced and the center point markers corresponding to the navigation warning data are less than or equal to 20 pixels apart from each other on the map, these center point markers corresponding to the navigation warning data are aggregated into one point. The aggregation separation means that when the map scale level is enlarged and the center point markers corresponding to the navigation warning data are more than 20 pixels apart from each other on the map, the aggregated center point markers will be separated and displayed individually.

[0025] The present invention also provides a ship navigation warning visualization display and maintenance system, including a data collection module connected in sequence for collecting real-time data of navigation warnings issued by maritime administrations around the world and classifying, summarizing, and organizing them according to data characteristics, a data maintenance module for displaying the real-time data of navigation warnings collected by the data collection module and supporting manual editing, deletion, and addition operations on the displayed data, a data display module for drawing the data operated by the data maintenance module onto a web map in different graphical ways for front-end page display, and a data monitoring module for listening to the zoom-in and zoom-out events of the web map drawn by the data display module. Each of the different graphics corresponds to a center point marker, and the center point marker is drawn on the map. The data feedback obtained by the data monitoring module is sent back to the data display module to perform aggregation and aggregation separation display on the center point markers on the map.

[0026] In the above system, the web map simultaneously draws two map copies on the left and right. The web map supports pop-up windows. When the mouse moves over the center point marker, a pop-up window automatically pops up to display the current navigation warning content. When the mouse moves away from the center point marker, the pop-up window automatically disappears.

[0027] Beneficial effects:

[0028] The present invention provides a method and system for visual display and maintenance of ship navigation warnings. The method includes collecting navigation warning data issued by maritime administrations around the world, classifying, summarizing, and organizing the data according to data characteristics, automatically parsing the collected navigation warning data and displaying it in the form of a navigation warning list, and supporting manual editing, deletion, and addition operations for each piece of displayed navigation warning data to ensure that the data displayed on the front-end page for users to view later is accurate, improving the accuracy of navigation warning data; the above-mentioned manually operated navigation warning data is visually displayed on the map using different graphics, facilitating users to intuitively and quickly view all navigation warning data, solving the problem that currently, after receiving a navigation warning, the ship party needs to search one by one on the map according to the location and area of the navigation warning, which is not intuitive and consumes a lot of time; the map simultaneously draws two map copies on the left and right to achieve the effect of continuous dragging and circular display of the map, just like the effect of tiling a circular map, further facilitating users to intuitively view navigation warnings.

[0029] Each piece of warning data displayed in the navigation warning list contains an icon indicating whether the data has been confirmed, facilitating the operator to view whether the navigation warning data has been processed, accelerating the processing of aviation warning data, and improving the efficiency of the operator to confirm navigation warning data.

[0030] For those with the center point outside the polygon, the center point is adjusted, and the centroid of the polygon is used as the center point to facilitate user viewing.

[0031] The map supports pop-up windows. When the mouse moves to the center point marker, a pop-up window automatically pops up to display the current navigation warning content. When the mouse moves away from the center point marker, the pop-up window automatically disappears, further improving the efficiency of users to view navigation warning data.

[0032] When the navigation warning data crosses 180 degrees, there will be problems with the display of the data on the map. The present invention processes the navigation warning data that crosses 180 degrees and solves the problem of incorrect display. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of the ship navigation warning visual display and maintenance solution in an embodiment of the present invention.

[0034] Figure 2 It is a schematic diagram of the display of different graphics on the map in an embodiment of the present invention.

[0035] Figure 3 It is a schematic diagram showing that the center point of an irregular polygon is outside the graphic in an embodiment of the present invention.

[0036] Figure 4 It is a schematic diagram of the corrected center point of an irregular polygon in an embodiment of the present invention.

[0037] Figure 5 The visualization display and maintenance system diagram of ship navigation warnings in the embodiments of the present invention. Specific embodiments

[0038] The present invention will be further described below with reference to the accompanying drawings:

[0039] A method for visualizing and maintaining ship navigation warnings, as Figure 1 shown, includes the following steps:

[0040] S1: Data collection and collation: Collect navigation warning data issued by maritime administrations around the world, and classify, summarize and collate them according to data characteristics; the navigation warning data are real-time navigation warnings issued by maritime administrations around the world.

[0041] In a specific embodiment of the present invention, a crawler is used to collect and parse real-time data of navigation warnings issued by maritime administrations around the world, and after classifying, summarizing and collating according to data characteristics, it is stored in a database; the data characteristics include: warning area type, center point of the warning area, longitude and latitude of the warning area, warning title, warning details, release date.

[0042] S2: Data maintenance: Automatically parse the data obtained in S1 and display it in the form of a navigation warning list, and support manual editing, deletion and addition operations on each navigation warning data displayed.

[0043] In a specific embodiment of the present invention, it specifically includes:

[0044] (1) Through a web page, that is, the management background page, automatically parse the data collected and collated in S1, and perform manual processing operations such as visual editing, deletion, and addition on the data with problems in the parsed display on the web page; the management background page can automatically confirm the navigation warning data.

[0045] (2) Each warning data in the navigation warning list has a small vertical bar icon, and the icon has three colors: blue represents that this warning has been automatically calculated and confirmed by the computer without error; green represents that this warning has been manually confirmed; red represents that this warning has neither been automatically calculated and confirmed by the computer nor manually confirmed. Different colors can facilitate manual follow-up and confirmation of the data correctness; in the following steps, only blue and green data will be displayed to users in the foreground, and unconfirmed data cannot be seen by users, thus ensuring the correctness of the data obtained by users.

[0046] S3: Data display: The navigation warning data obtained in S2 is visually displayed by drawing different graphics on a map; two map copies, one on the left and one on the right, are simultaneously drawn on the map; each of the different graphics corresponds to a center point marker, which is also drawn on the map; the map is the interface presented to the user at the front end.

[0047] In a specific embodiment of the present invention, the map is a web map, and the web map is based on Leaflet map and is displayed in the form of the different graphics, including: points, multi-points, lines, polygons, circles, sectors, as Figure 2 shown, and each piece of data is drawn as a different graphic according to its respective data characteristics;

[0048] Each of the different graphics corresponds to a center point marker (marker). For a point, a center point marker is drawn on the web map, which is the point; for multi-points, multiple single points and a center point calculated from the coordinates of these multi-points are marked with a marker on the map; for lines, polygons, circles, and sectors, the center points are marked with markers; all these marker markers represent the current navigation warning data and are also drawn on the web map. In some cases, as Figure 3 shown, the center point of a polygon is not inside the polygon but outside it. In the present invention, the center points of these polygons are adjusted. The adjustment method is: using the centroid instead of the center. A polygon can be divided into multiple simple graphics. The centroid coordinates of the polygon are G(x,y), and the calculation formulas for x and y are:

[0049]

[0050] where n is the number of simple graphics, S i is the area of the i-th simple graphic, G ix is the x coordinate of the centroid of the i-th graphic, and G iy is the y coordinate of the i-th centroid; x and y are obtained through the above formulas, and G(x,y) is used as the centroid coordinates of the graphic as the center point. The position of the center point of the graphic after adjusting the center point is as Figure 4 shown.

[0051] The web map can simultaneously draw the corresponding navigation warning graphics on the map copies on both the left and right sides of the main map, achieving the effect of continuous dragging and circular display of the map, just like the effect of tiling a circular map.

[0052] During the actual navigation of a ship, there is a problem that the navigation warning data crosses 180 degrees. The navigation warning data is a line, with the starting point A(164.67029, 39.43366) and the ending point B(-167.08772, 40.00198) of this line. Before the data is processed, when this line is drawn on a map, it will be a line that crosses the entire continent from the leftmost to the rightmost. However, the Earth is round, and this line is obviously not the most correct result. In the present invention, the following formula is used to adjust the longitude of each point on this line:

[0053]

[0054] Where: The longitude and latitude source data is an array, x i is the i-th longitude in the source data array; c is the offset, starting from c = 0; y i is the initial x i The calculated longitude; x i+1 is the (i + 1)-th longitude in the source data array; c * y i is the converted longitude; f(x i , c) represents traversing and calculating starting from the i-th longitude in the longitude and latitude array, with the offset c starting from zero; f(x i ) represents deriving the y i value during the conditional traversal process, and when |x i - x i+1 | > 180, that is, when the absolute value of the difference between the (i + 1)-th longitude and the i-th longitude is greater than 180 degrees, y i is returned, or until the last data is traversed and there is no data meeting this condition, x i is assigned to y i ; f(c, y i ) represents continuing to traverse starting from zero internally. Based on the y i value obtained from f(x i ), y i+1 is the value obtained from f(x i+1 ). When y i ≤0 ∪ y i+1 ≥0, the offset c is incremented by 1. When y i ≥0 ∪ y i+1 ≤0, the offset c is decremented by 1; when the entire longitude and latitude array traversal ends, the final offset c and y i are derived and calculated, and their product is the finally obtained correct longitude.

[0055] After processing all the longitudes of this warning data by the above method, the correct graph can be drawn.

[0056] The map supports pop-up windows, which facilitates users to view and copy navigation warning data. When the mouse moves over a marker, a tips pop-up window that displays the current navigation warning content will automatically pop up. When the mouse moves away from the marker, the tips pop-up window will automatically disappear. The default pop-up window of the Leaflet map library expands upward. To avoid the map shaking caused by the pop-up display of navigation warning data with a dimension higher than 70, special processing is required to make the tip pop-up window expand downward. The processing of the pop-up window specifically includes the following steps:

[0057] Step 1: Set a custom className when creating the center point marker corresponding to the navigation warning data;

[0058] Step 2: Rotate all pop-up window directions 180 degrees in the style file to make them default to downward;

[0059] Step 3: When drawing the center point marker corresponding to each navigation warning data, judge its dimension. When the dimension is less than -35 degrees, obtain the current dom element through marker._popup.getElement(), and set the transform property of the style of this dom element to rotate(0deg) to make the window pop-up direction upward.

[0060] S4: Listen for the zoom-in and zoom-out events of the map scale level described in S3, and aggregate and display the aggregation and separation of the center point markers according to the monitored events.

[0061] In a specific embodiment of the present invention, listen for the map level zoom event. When the local map level is less than level eight and the distance between navigation warning data is less than ten meters, or the center point markers corresponding to the navigation warning data are less than or equal to 20 pixels apart on the map, aggregate settings are made for the center point markers of the navigation warning data to form an aggregation cluster (points with close distances are aggregated into one point), reducing the inconvenience caused by a large amount of dense warning data and enabling users to view and operate clearly and intuitively on the map. When the navigation warning data is aggregated, clear its drawn graphics; listen for the map scale level zoom-in event. When the navigation warning data is not aggregated, call the drawing method to draw the current navigation warning graphics; when the map scale level zooms in to level eight (levels 2 - 16), and the distance between multiple navigation warning data is less than ten meters, or the center point markers corresponding to the navigation warning data are more than 20 pixels apart on the map, even in the aggregated state, their respective graphics are still drawn.

[0062] Generally, the graphic areas of aggregated navigation warning data do not need to be drawn. Only for data with a distance less than ten meters from each other and above map level eight, the graphic areas of these data need to be drawn. The following method is used for graphic drawing in the present invention:

[0063] Step 1: Avoid thread congestion and create a web worker sub-thread to execute the file warnWork;

[0064] Step 2: Write a data processing method in the warnWork file. Calculate the distance formula based on the latitudes and longitudes of two points:

[0065] D = R * arcos[cos(y1) * cos(y2) * cos(x1 - x2) + sin(y1) * sin(y2)]

[0066] Where: R is the radius of the earth, and (x1, y1) and (x2, y2) are the latitudes and longitudes of these two points on the spherical surface.

[0067] Traverse all navigation warning data, find the data with a distance of ten meters between the center points through the above formula and mark it with isNear, and finally return the processed data to the main thread.

[0068] Step 3: Listen for the map zoom event. When the local layer level is eight or above, judge whether the navigation warning data has the isNear mark made in the second step above. If it has the mark, call the graphic drawing method; when the local layer level is lower than eight, call the clear layer method to clear the corresponding graphics.

[0069] The present invention also provides a visualization display and maintenance system for ship navigation warnings, as Figure 5 shown, including a data collection module connected in sequence for collecting real-time navigation warning data issued by maritime administrations around the world and classifying, summarizing, and sorting according to data characteristics, a data maintenance module for displaying the real-time navigation warning data collected by the data collection module and supporting manual editing, deletion, and addition operations on the displayed data, a data display module for drawing the data operated by the data maintenance module onto a web map in different graphic ways for front-end page display, and a data listening module for listening to the zoom-in and zoom-out events of the web map drawn by the data display module; each of the different graphics corresponds to a center point marker, and the center point marker is drawn on the web map; the data feedback by the data listening module is sent back to the data display module to perform aggregation and aggregation separation display on the center point markers on the web map.

[0070] In the above system, the web map simultaneously draws two map copies on the left and right; the web map supports pop-up windows. When the mouse moves to the center point marker, a pop-up window automatically pops up to display the current navigation warning content. When the mouse moves away from the center point marker, the pop-up window automatically disappears.

[0071] It should be noted that the specific embodiments described above can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. Therefore, although this specification has described the present invention in detail with reference to the accompanying drawings and embodiments, those skilled in the art should understand that the present invention can still be modified or equivalently replaced. In short, all technical solutions and their improvements that do not depart from the spirit and scope of the present invention should be covered by the protection scope of the patent of the present invention.

Claims

1. A method for visual display and maintenance of ship navigation warnings, characterized in that: The steps include: S1: Data collection and collation: collect navigation warning data issued by maritime authorities around the world, and classify and summarize them according to data characteristics; the navigation warning data are navigation warnings issued in real time by maritime authorities around the world; S2: Data maintenance: Automatically parse the data obtained in S1 and display it in the form of a navigation warning list, and support manual editing, deletion and addition of each displayed navigation warning data; S3: Data display: The navigation warning data obtained in S2 is drawn on a map in different graphic forms for visual display; the map simultaneously draws two left and right map copies; the different graphics each correspond to a center point mark, and the center point mark is also drawn on the map; S4: Listen to the zooming and enlarging events of the map scale level in S3, and perform aggregation and aggregation separation display on the center point marks according to the listened events.

2. The method for visual display and maintenance of ship navigation warning according to claim 1, characterized in that: The data features described in S1 include: warning area type, center point of the warning area, longitude and latitude of the warning area, warning title, warning details, and release date.

3. The method for visualizing and maintaining ship navigation warnings according to claim 1, characterized in that: In S2, the data obtained in S1 is automatically parsed through a web page and displayed in the form of a navigation warning list. Each navigation warning displayed in the navigation warning list includes an icon indicating whether the data is confirmed.

4. The method for visualizing and maintaining ship navigation warnings according to claim 1, characterized in that: The map in S3 is a web map, which is based on Leaflet map and is displayed in the form of different graphics, including: points, multiple points, lines, polygons, circles, and sectors; the center point corresponding to the point is marked as the current point; the center point mark corresponding to the multiple points is the center point calculated by the coordinates of these points; the center point mark of the line, polygon, circle and sector is the center point of the corresponding graphic.

5. The method for visualizing and maintaining ship navigation warnings according to claim 4, characterized in that: For the center point outside the polygon, the center point is adjusted. The adjustment method is: replace the center point with the center of gravity. The polygon is divided into multiple simple graphics. The coordinates of the center of gravity of the polygon are G(x,y). The calculation formula of x,y is: Where n is the number of simple graphics, S i is the area of ​​the ith simple figure, G ix is the x coordinate of the center of gravity of the ith figure, G iy is the y coordinate of the i-th centroid; x and y are obtained through the above formula, and G(x,y) is the centroid coordinate of the figure.

6. The method for visualizing and maintaining ship navigation warnings according to claim 5, characterized in that: The map in S3 supports pop-up windows. When the mouse moves to the center point mark, a pop-up window displaying the current navigation warning content will automatically pop up. When the mouse moves away from the center point mark, the pop-up window will automatically disappear.

7. The method for visualizing and maintaining ship navigation warnings according to claim 7, characterized in that: S3 includes processing the pop-up window, and the specific steps include: Step 1: Set the custom className when creating the center point mark corresponding to the navigation warning data; Step 2: Rotate all pop-up windows 180 degrees in the style file so that they are facing downward by default; Step 3: When drawing the center point mark corresponding to each navigation warning data, determine its dimension. When the dimension is less than -35 degrees, get the current DOM element through marker._popup.getElement(), and set the transform attribute of the style of this DOM element to rotate(0deg) so that the window pops up upward.

8. The method for visualizing and maintaining ship navigation warnings according to claim 2, characterized in that: The map in S3 organizes the aviation warning data spanning 180 degrees. The organization method is to adjust the longitude of the warning area in the aviation warning data. The adjustment formula is as follows: Among them: the latitude and longitude source data is a set of arrays, x i is the i-th longitude in the longitude and latitude array; c is the offset, starting from c=0; y i f(x i ) calculated longitude; x i+1 Indicates the i+1th longitude in the longitude and latitude array; y i+1 f(x i+1 ) Calculated longitude; c*y i is the converted longitude; f(x i ,c) means starting from the i-th longitude in the longitude and latitude array, and the offset c starts from zero; f(x i ) indicates that y is pushed during the conditional traversal process i value,|x i -x i+1 |>180 means that when the absolute value of the difference between the i+1th longitude and the ith longitude is greater than 180 degrees, y is returned. i , or until the last data is traversed and no data meets this condition, then x i Assign to y i ; f(c,y i ) indicates that the internal traversal continues from zero, according to f(x i )The obtained y i Value, y i+1 f(x i+1 ) when y i ≤0∪y i+1 ≥0, the offset c is increased by 1, when y i ≥0∪y i+1 ≤0, the offset c is reduced by 1; when the entire longitude and latitude array is traversed, the final offset c and y are derived and calculated i , and the multiplication is the final correct longitude.

9. The method for visualizing and maintaining ship navigation warnings according to claim 8, characterized in that: The aggregation in S4 means that when the map scale level is reduced, the center point marks corresponding to the navigation warning data are less than or equal to 20 pixels apart on the map, and the center point marks corresponding to these navigation warning data are aggregated into one point; the aggregation separation means that when the map scale level is enlarged, when the center point marks corresponding to the navigation warning data are more than 20 pixels apart on the map, the aggregated center point marks will be separated and displayed separately.

10. A ship navigation warning visualization display and maintenance system, characterized in that: The invention comprises a data collection module which is connected in sequence and is used to collect the real-time data of navigation warnings issued by maritime authorities around the world and classify, summarize and organize them according to data characteristics, a data maintenance module which is used to display the real-time data of navigation warnings collected by the data collection module and support manual editing, deletion and addition of the displayed data, a data display module which is used to draw the data operated by the data maintenance module on a web map in different graphic ways for front-end page display, and a data monitoring module which is used to monitor the zoom-in and zoom-out events of the web map drawn by the data display module; the different graphics respectively correspond to a center point mark, and the center point mark is drawn on the map; the data monitored by the data monitoring module is fed back to the data display module, and the center point mark on the map is aggregated and displayed separately.

11. The ship navigation warning visualization display and maintenance system according to claim 10, characterized in that: The web map simultaneously draws two left and right map copies; the web map supports pop-up windows. When the mouse moves to the center point mark, a pop-up window automatically pops up to display the current navigation warning content. When the mouse moves away from the center point mark, the pop-up window automatically disappears.

Images