A dynamic modeling method of an electronic chart product

Abstract

The application relates to a dynamic modeling method of an electronic chart product, and belongs to the technical field of marine surveying and mapping. The method realizes unified management of the semantic structure of diversified electronic chart products by constructing an extensible concept dictionary and an element catalog; XSD files are generated based on the element catalog, and a relational database structure suitable for a general geographic information platform is automatically created; and visual rendering conforming to the electronic chart standard is realized through graphic expression catalog. The application realizes compatible adaptation of the electronic chart data model and the basic geographic information platform, solves the problems of loss of hierarchical structure, non-standard symbolization, high manual configuration cost and the like in the application of the electronic chart data in the traditional geographic information system, has the advantages of flexible modeling, high automation degree and strong expansibility, and can effectively improve the fusion and sharing of various marine space information.

Description

Technical Field

[0001] This invention belongs to the field of marine surveying and mapping technology, and in particular to a dynamic modeling method for electronic nautical chart products. Background Technology

[0002] Nautical charts are models of marine spatial information and important tools for humankind to understand and transform the ocean world. Due to varying needs and uses across different fields, different groups have different understandings of the marine spatial world, leading to a diversity of nautical chart types, such as nautical charts, hydrographic charts, and meteorological charts. In the information age, various marine-related departments, according to their respective responsibilities, have carried out digitalization and standardization work on the design, production, distribution, and application of relevant nautical chart types, resulting in different nautical chart products. However, due to the complexity of marine disciplines and the existence of industry fragmentation, current nautical chart products lack overall coordination in terms of semantic concepts, data structures, and graphic representation, making deep integration and fusion difficult. This, in turn, affects people's comprehensive understanding and utilization of the marine world.

[0003] For a long time, mainstream geographic information platforms have had very limited support for diverse nautical chart products. They primarily rely on application developers to create corresponding data loading and display modules for specific chart products. Once a new chart product emerges, it often cannot be directly supported, requiring the development of new software modules, which greatly limits the improvement of application capabilities. Even for common nautical chart products like electronic nautical charts, the significant structural differences between their data models and traditional geographic information system (GIS) platforms lead to the following problems: (1) Loss of hierarchical structure. For traditional GIS platforms, if common formats such as Shapefile (.shp) or geographic database (.gdb) are used to save nautical chart data, only basic geometric information and a small number of attribute fields can usually be retained. However, the complex semantic structures such as information types, associations, and nested structures required for electronic nautical chart expression are often difficult to retain.

[0004] (2) Non-standard symbolization. The symbol library system built into the traditional GIS platform cannot cover the complex requirements of electronic nautical charts, so key nautical elements such as lighthouses, buoys, and contour lines cannot accurately express their shape, color, flashing frequency and other characteristics when displayed, which affects the judgment of navigation safety.

[0005] (3) High cost of manual configuration. In order to make the traditional GIS platform as close as possible to the display style of electronic nautical charts, technicians often need to manually rebuild the field structure, set foreign key relationships, and configure the rendering style one by one. The whole process is time-consuming, laborious and prone to errors. Especially when facing the integrated application of different types of electronic nautical charts, it is difficult to form a workflow that can be quickly replicated.

[0006] The aforementioned issues have created a technological gap between electronic nautical charts and general GIS, severely restricting the sharing and application of electronic nautical chart data in a wider range of business scenarios. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and propose a dynamic modeling method for electronic nautical chart products. This method solves the problem of insufficient support for diverse nautical chart products by existing basic geographic information platforms, improves the coordination and consistency and information sharing capabilities among nautical chart products, and realizes the standardized design and application of nautical chart products.

[0008] The technical problem solved by this invention is achieved through the following technical solution: A dynamic modeling method for electronic nautical chart products includes the following steps: Step 1: Perform domain analysis on the current electronic chart product, identify relevant terms, and search for corresponding concepts in the pre-set concept dictionary; if they exist, proceed to Step 2; if they do not exist, register the new concept and its semantic definition in the concept dictionary, and then proceed to Step 2. Step 2: Based on the concept dictionary, extract elements, attributes, information types and relationship names, configure the attribute set, allowed spatial geometry types, semantic relationships between elements and the association between information and objects for each element, and save the configuration results as an XML format element catalog file; Step 3: Construct a graphic representation catalog based on the feature catalog described in Step 2. The graphic representation catalog includes: point symbols described in SVG files, line types and polygon fill patterns described in XML files, and graphic representation rules written in a scripting language. The graphic representation rules determine the symbol mapping relationship based on feature attribute values, geometric types, and context parameters. Step 4: Embed the feature catalog and graphic representation catalog into the basic geographic information platform, parse the feature catalog to generate the corresponding XSD structure file, and dynamically create a relational database table structure based on the XSD; Step 5: Based on the created database structure, realize the creation or batch import of electronic nautical chart data; Step 6: The platform loads the parsed nautical chart data, calls the graphic representation rules to return symbol definitions and parameters, and completes the visualization rendering that conforms to the electronic nautical chart standard.

[0009] Furthermore, the concept dictionary in step 1 includes: a list of nautical chart products, a list of element types, a list of simple attributes, a list of complex attributes, a list of attribute value ranges, a list of information types, and a list of association rules, which supports user-defined expansion and can be used for rapid modeling of new nautical chart products.

[0010] Furthermore, the graphical representation of linear and planar features in step 3 adopts a composite symbol method, including line type, line color / planar fill color, and auxiliary symbols inserted along the line, and their combination rules are defined through an XML file.

[0011] Furthermore, the database structure created in step 4 includes: a nautical chart meta-information table, a topology table, various element tables, an information type table, an element-topology relationship table, an element-element relationship table, an element-information type relationship table, and a topology-information type relationship table.

[0012] Furthermore, the data import process in step 5 includes: parsing the original nautical chart data to construct a memory cache structure, sequentially writing metadata, geometric objects, feature instances and relationships into the corresponding database tables, and establishing reference relationships between features and geometry.

[0013] Furthermore, the graphic representation rules in step 4 are implemented using the LUA scripting language, which supports conditional judgment, loop control and function calls, and dynamically selects symbol style, color, display level and drawing priority based on attribute values ​​or context parameters.

[0014] Furthermore, the relationship types in the feature catalog in step 4 include: additional information association, spatial quality association, and aggregation relationship, which are used to bind features with non-spatial information, quality descriptions, and logical groupings.

[0015] The advantages and positive effects of this invention are: This invention enables lossless conversion and semantic consistency maintenance from diverse nautical chart product data models to a general geographic information platform. It achieves global semantic coordination and unification through a concept dictionary, standardizes the description of various elements and their relationships through an element catalog, and enables dynamic creation and loading display of the nautical chart product database through an element catalog XSD structure file. It features flexibility, speed, and strong adaptability. Attached Figure Description

[0016] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a diagram showing the entity relationship of the database table structure in this invention. Figure 3 This is a schematic diagram of the registration interface for the submarine cable concept of this invention; Figure 4 This is the cable type concept registration interface for an embodiment of the present invention; Figure 5 This is a schematic diagram of the concept document for a marine obstacle thematic map according to an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the basic conceptual information of a marine obstacle thematic map according to an embodiment of the present invention; Figure 7This is a schematic diagram of the interface for constructing the submarine cable element catalog according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the product element catalog of the marine obstacle thematic map according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the dot symbol definition in WRECKS05.svg, an embodiment of the present invention. Figure 10 This is a schematic diagram of the dot symbols in the WRECKS05.svg file, representing an embodiment of the present invention. Figure 11 This is a schematic diagram of the directory where the dot symbols in WRECKS05.svg are saved, according to an embodiment of the present invention. Figure 12 This is a schematic diagram illustrating the line symbol definition in CBLSUB06.xml, an embodiment of the present invention. Figure 13 This is a schematic diagram illustrating the symbol stroke and position attribute settings in CBLSUB06.xml, an embodiment of the present invention. Figure 14 This is a schematic diagram illustrating the symbol line style settings in CBLSUB06.xml, an embodiment of the present invention. Figure 15 This is a schematic diagram of the directory where the CBLSUB06.xml symbol line is saved in an embodiment of the present invention; Figure 16 This is a schematic diagram illustrating the definition of fill symbols for a surface in an embodiment of the present invention; Figure 17 This is a schematic diagram illustrating the rule settings for submarine cable elements in an embodiment of the present invention; Figure 18 This is a schematic diagram of the LUA script illustrating the rules for illustrating submarine cable elements in an embodiment of the present invention; Figure 19 This is a schematic diagram illustrating the thematic representation of marine obstacles in embodiments of the present invention; Figure 20 This is a representation of metadata in an embodiment of the present invention; Figure 21 This is a schematic diagram of the "topology table" in an embodiment of the present invention; Figure 22 This is a schematic diagram of the curve "topology table" in an embodiment of the present invention; Figure 23 This is a schematic diagram of the "topology table" of the combined curves in an embodiment of the present invention; Figure 24 This is a schematic diagram of the surface "topology table" in an embodiment of the present invention; Figure 25 This is a schematic diagram of the "Element Table" in an embodiment of the present invention; Figure 26 This is a schematic diagram of the "element table" of multiple water depth points according to an embodiment of the present invention; Figure 27This is a schematic diagram of the "Information Type Table" in an embodiment of the present invention; Figure 28 This is a schematic diagram of the "Relationship Table between Elements and Information Types" in an embodiment of the present invention; Figure 29 This is a schematic diagram illustrating the thematic representation of marine obstacles in embodiments of the present invention; Figure 30 This is a schematic diagram of the marine obstacle thematic map engineering information according to an embodiment of the present invention; Figure 31 This is a schematic diagram of the engineering layer structure of the marine obstacle thematic map according to an embodiment of the present invention; Figure 32 This is a schematic diagram illustrating the information of product 101C100000000 yuan in an embodiment of the present invention; Figure 33 A schematic diagram of the cable zone elements with RCID of 94 in an embodiment of the present invention; Figure 34 This is a schematic diagram of the "Element Table" for a cable zone with an RCID of 94 according to an embodiment of the present invention; Figure 35 This is a schematic diagram of a surface "topology table" with RCID of 2 in an embodiment of the present invention; Figure 36 This is a schematic diagram of the "topology table" of the combined curve with RCID of 2 in an embodiment of the present invention; Figure 37 This is a schematic diagram of a curve "topology table" with an RCID of 936 in an embodiment of the present invention; Figure 38 A schematic diagram of a submarine cable with an RCID of 59 according to an embodiment of the present invention is shown; Figure 39 This is a schematic diagram of the "feature table" for a submarine cable with RCID 59 according to an embodiment of the present invention; Figure 40 This is a schematic diagram of a line "topology table" with RCID 906 in an embodiment of the present invention; Figure 41 A schematic diagram of a shipwreck with an RCID of 34 according to an embodiment of the present invention; Figure 42 This is a schematic diagram of the "element table" of a shipwreck with RCID 34 according to an embodiment of the present invention; Figure 43 This is a schematic diagram of the "topology table" of points with RCID 66 in an embodiment of the present invention; Figure 44 This is a schematic diagram of the LUA function entry point for the marine obstacle thematic map product according to an embodiment of the present invention; Figure 45 This is a schematic diagram of LUA rendering of the marine obstacle thematic map product according to an embodiment of the present invention; Figure 46This is a schematic diagram illustrating the export of a marine obstacle thematic map product as a 101C100000000.000 file according to an embodiment of the present invention. Figure 47 This is a schematic diagram of browsing 101C100000000.000 using third-party nautical chart software, as an embodiment of the present invention. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings.

[0018] A dynamic modeling method for electronic nautical chart products, such as Figure 1 As shown, it includes the following steps: Step 1: Analyze the domain issue, identify relevant concepts, and define them. Analyze the related terminology for the nautical chart product to be created. Check the concept dictionary to see if any existing concepts can be used to express the relevant terms. If so, proceed directly to the next step; otherwise, register and add the concept and its definition to the concept dictionary, and then proceed to the next step.

[0019] Step 2: Extract relevant concept definitions and construct a catalog of nautical chart product elements. Analyze the entity composition and relationships of the nautical chart product, extract relevant concepts from the concept dictionary as names for elements (classes), attributes, information types, and relationships, and determine the binding relationships: which attributes each element contains, their types and value ranges, which spatial geometry types each element is allowed to use, which relationships are allowed between different elements, which relationships are allowed between different attributes, and which elements an information type can be associated with. Save the above configuration file as an XML file, which is the element catalog.

[0020] Step 3: Construct a graphic representation catalog based on the feature catalog. The graphic representation catalog includes symbol definitions and graphic representation rules. The various symbol definitions are described in XML files, including point primitives, line types, and polygon patterns. The graphic representation rules are implemented using a scripting language, which defines the mapping relationship between each feature in the feature catalog and the symbol definition name and parameters under different conditions. These conditions include the attribute values, spatial geometry type, and context parameters of the feature object instance.

[0021] Step 4: Embed the feature catalog and graphic representation catalog into the basic geographic information platform. Copy the feature catalog XML and graphic representation catalog to a folder that the basic geographic information platform can recognize; use the feature catalog XML to generate the corresponding XSD structure file, such as... Figure 2 As shown, the relational database table structure is dynamically generated based on the XSD file.

[0022] This step includes the following steps: Step 4.1: Create a database based on the nautical chart sheet division and electronic nautical chart product version information, and establish an element catalog table in this dataset to store the element model structure information defined by the XSD file; at the same time, construct the nautical chart metadata table and its attribute field structure according to the metadata structure defined in the XSD to record metadata such as map sheet identification, spatial range, and coordinate system.

[0023] Step 4.2: Create a unified geometry and topology support table. Each table has fields for geometry reference identifier, feature reference identifier, and data version identifier to achieve centralized storage and management of spatial geometry and support geometry sharing and topology relationship maintenance among features.

[0024] Step 4.3: Based on the list of feature types defined in XSD, create corresponding nautical chart feature tables for each type, and generate table structures synchronously according to their attribute definitions; perform type mapping for specific semantic attributes according to preset rules to adapt to their data characteristics; for each feature table, establish corresponding feature relationship tables and feature-topology relationship tables to express semantic associations and spatial binding; for water depth features, additionally configure point geometric attributes and water depth value attributes to support thematic data modeling.

[0025] Step 4.4: Based on the information type list defined in XSD, create the corresponding information type table and establish the relationship table between information type and elements, and between information type and geometry.

[0026] Step 5: Based on the aforementioned relational database table structure, the basic geographic information platform realizes the creation or import of nautical chart product data.

[0027] Step 5.1: Parse the electronic nautical chart product data to be imported, construct a data cache structure in memory, and organize it according to the logical hierarchy of metadata, geometric objects, feature instances and relationships, where complex attributes are encapsulated in a structured data format; Step 5.2: Verify whether the version information of the electronic nautical chart product data is consistent with the version of the target database logical dataset. If they are consistent, perform the subsequent import operation; if they are inconsistent, terminate the import process. Step 5.3: Write the metadata in the cache structure into the nautical chart metadata table created in Step 4; Step 5.4: Import the various geometric objects in the cache structure into the corresponding unified topology table, including points, multi-points, curves, composite curves and surfaces, and establish a unique identifier for each geometric object for subsequent association and reference; Step 5.5: Import the feature instances in the cache structure into the corresponding feature table one by one according to their type, and write their attribute values ​​into the table synchronously. Complex attributes are stored in a structured format. For non-depth features, establish their binding relationship with geometric objects through a relationship table. For depth features, match and associate their attributes with the imported multi-point geometry. Step 5.6: Import the information type instances in the cache structure into the corresponding information type table, and establish their association with the features or geometric objects through the relationship table.

[0028] Step 6: The basic geographic information platform loads and parses the nautical chart product data from the database, calls the graphic representation rules and returns the symbol definition name and parameters corresponding to the feature object instance, and finally renders and generates the display of this type of nautical chart product.

[0029] Based on the above method, the following detailed description of the implementation examples of the present invention, combined with the creation process and accompanying drawings of the "Marine Obstacles Thematic Map" thematic product, will further illustrate the effects of the present invention.

[0030] Step 1: Analyze the issues in the field of marine obstacles, identify relevant concepts, and provide definitions.

[0031] A systematic analysis of the application requirements for the "Marine Obstacles Thematic Map" reveals its core application scenarios as maritime navigation safety assessment, marine engineering planning, and emergency response decision support. Against this backdrop, several key geographic element concepts are identified and defined as the foundation for subsequent data modeling and product development. Analysis indicates that this thematic product focuses on the following five core entities: (1) An offshore platform is defined as a man-made fixed or floating structure located in nearshore or offshore areas for oil and gas extraction, wind power generation, scientific research and observation or other industrial purposes. In electronic nautical chart products, it is modeled as a point feature to identify its geographical location and carry attribute information related to its safe navigation.

[0032] (2) Submarine pipelines are defined as: linear artificial facilities laid on the seabed for transporting oil, natural gas or other fluid media, and are expressed as key navigational obstacles in electronic charts to ensure the safety of ship navigation, prevent anchor damage accidents, and support marine resource development and emergency response.

[0033] (3) Submarine cables are defined as artificial linear facilities laid on the seabed for transmitting power or communication signals, including various types such as power cables, communication optical cables, mooring cables, and ferry traction cables.

[0034] (4) Shipwreck is defined as: a ship or its wreckage that has sunk in the water and is represented as a key navigational obstacle element in electronic charts to ensure the safety of ship navigation, prevent collisions or anchor damage accidents, and support marine engineering planning, underwater archaeology and emergency response.

[0035] (5) Reefs are defined as: rocks, coral reefs or other hard geological structures located underwater or near the water surface, with shallow water at their tops, posing a risk of collision or grounding to ships. They are expressed as point or area elements on electronic charts and are key warning elements for navigation safety in nearshore and island / reef waters.

[0036] Further investigation of the existing concept dictionary confirmed that the above concept has not yet been registered. Therefore, the following registration operation was completed using the feature concept dictionary editing tool: (1) Offshore platforms, submarine pipelines, submarine cables, shipwrecks, and reefs are categorized as element concepts, and their formal definitions are entered separately. For example, the registration of the concept of submarine cables includes: application area, name, code, definition, etc. Submarine cable concept registration

[0037] As shown in the table above, Figure 3 The schematic diagram of the submarine cable concept registration interface of this invention sets the submarine cable element definition information, including the application field as IHO Hydro, the name as submarine cable, the code as CableSubmarine, the alias as submarine cable CBLSUB, the proposal status as final, the Chinese description defined as submarine cable, the usage type as geographical, and the remarks which can be empty and are the English description of submarine cable definition.

[0038] (2) Classify semantic items used to describe the characteristics of elements into attribute concepts, and define their data types, units, and value ranges. For example, the registration of cable type concepts includes: application area, name, code, alias, proposal status, definition, data type, remarks, value range binding, etc.

[0039] Cable type concept registration

[0040] After defining the concept of submarine cables, the attribute concepts included in submarine cables are defined, such as the concept of cable type. As shown in the table above, in Figure 4 In this embodiment of the invention, the cable type concept registration interface sets cable type definition information, wherein the application field is IHO Hydro, the name is CATCBL, the code is categoryOfCable, the alias is cable type, the proposal status is Final, the Chinese description defined as cable type definition is defined, the data type is enumeration type, and the remarks are empty.

[0041] Cable type value range concept registration

[0042] Following the above definition of submarine cables, we will continue in... Figure 4 The value range definition is completed in the table above. The conceptual value range for submarine cables is defined with five values: 1, 6, 7, 9, and 10. Figure 4 The number of value domain binding columns is 5. The name of column 1 is "Power Line", defined as the Chinese description of the power line definition, and numbered 1. Other values ​​6, 7, 9, and 10 are similar and are set in value domain 2, value domain 3, value domain 4, and value domain 5 respectively.

[0043] like Figure 5 As shown, after the concept registration of the marine obstacle thematic map is completed, it is saved as an XML file named "FCD.xml". This file can be referenced in the feature catalog construction.

[0044] Step 2: Extract relevant concept definitions from the marine obstacle thematic map concept file and construct a catalog of chart product elements. The creation of the element catalog related to the marine obstacle thematic map product follows these steps: (1) Define the element catalog metadata: like Figure 6 As shown, enter the product element catalog name, scope, application field, version number, version date, security level, role information, participants, organization, contact information, etc.

[0045] (2) Constructing elements (classes): Select and set elements such as offshore platforms, submarine pipelines, submarine cables, shipwrecks, and reefs from the element catalog concept dictionary.

[0046] (3) Constructing attributes: such as Figure 7 As shown, simple and complex attributes can be constructed. For example, simple attributes for submarine cables include: cable type (enumerated type, values ​​include: 1: power line, 6: mooring cable / chain, 7: ferry cable, 9: repeater cable, 10: communication cable), burial depth (floating-point type), and condition (enumerated type). Complex attributes for submarine cables include: cable name, whose sub-attributes include language and name, forming a nested structure. When the defined attribute concepts are used in the production element catalog information, the cable type (CATCBL) attribute can be bound to the submarine cable element, and the required enumerated values ​​for the submarine cable (not all need to be bound) and the multiplicity settings of this attribute can be defined.

[0047] (4) Constructing relationships. ① Constructing relationships between elements, such as submarine cable aggregation: Set the Mooring Trot Aggregation type to aggregate submarine cables with other mooring-related elements. ② Constructing relationships between elements and topology, such as: offshore platforms, shipwrecks, and reefs can be represented by points; submarine pipelines and submarine cables can be represented by curves; submarine cable zones can be represented by surfaces. ③ Constructing relationships between information and elements, such as setting submarine cable information association relationships: Set the Additional Information type association relationship to bind submarine cable elements with Contact Details information types.

[0048] (5) such as Figure 8 As shown, the catalog of marine obstacle thematic map product elements has been completed and saved as an XML file conforming to the XSD structure, named "MarineObstructeFC.xml".

[0049] Step 3: Construct a catalog of illustrations based on the XML file containing the product element catalog of the marine obstacle thematic map. The steps for creating the catalog of illustrations for the marine obstacle thematic map are as follows: (1) Define the concept of dot symbols such as WRECKS05.svg, and draw the symbol shapes and attributes. Specifically: The SVG file uses OFSPLF01.svg for offshore platforms, WRECKS05.svg for shipwrecks, and UWTROC04.svg for reefs. The SVG file defines parameters such as the width, height, symbol, and color of the dot symbol and saves them to the Symbols directory.

[0050] For example, Figure 9 This invention provides an embodiment of the WRECKS05.svg dot symbol definition diagram, which sets the symbol definition of WRECKS05.svg. Figure 10 This invention provides a schematic diagram of drawing dot symbols in the WRECKS05.svg file, demonstrating the visual editing and settings for the symbols in the WRECKS05.svg file. Figure 11 The schematic diagram of the dot symbol storage directory in the embodiment of this invention (WRECKS05.svg) shows the storage information of this symbol file.

[0051] (2) such as Figure 12 , 13 As shown in Figures 14 and 15, the concept of line symbols in CBLSUB06.xml is defined, and the symbol shapes and attributes are drawn. Specifically: Submarine cables use CBLSUB06.xml, an XML file that defines parameters such as line type, line width, and line color, and is saved in the LineStyles directory.

[0052] (3) Define the concept of face symbols such as PIPSOL06.xml, draw the symbol shapes and attributes, and define the face edge symbols according to (2) above. Specifically: The boundary markers for submarine pipeline zones use PIPSOL06.xml, without filler symbols; The boundary markers for submarine cable zones use CBLARE51.xml, without filler symbols.

[0053] like Figure 16 As shown, the XML file defines parameters such as line type, line symbol, line width, and line color for the face edges. The edge symbols are saved in the LineStyles directory, and the face fill symbols are saved in the AreaFills directory.

[0054] (4) After the symbols are defined, a mapping relationship between each element related to the marine obstacle thematic map and the symbol definition name and parameters under different conditions is established and saved as a LUA script.

[0055] For example, the rules for illustrating submarine cable elements are set as follows: Figure 17 , 18 As shown in Figure 19, first determine whether the geometry type is a line feature (PrimitiveType.Curve). If it is, proceed to the next step; otherwise, report an error and exit. Then, determine whether the cable type is 6 (mooring cable / chain). If it is, use the CBLSUB06.xml line symbol for symbol rendering; otherwise, use a simple line symbol with the color CHMGD for rendering.

[0056] (5) such as Figure 20 As shown, after the catalog of thematic representations of marine obstacles is constructed, it is stored in the form of file directories, including: point symbols, line symbols, area symbols, color tables, and LUA rules.

[0057] Step 4: Embed the feature catalog and graphic representation catalog into the basic geographic information platform. The marine obstacle thematic map will have its database table structure created on the basic geographic information platform according to the following steps: (1) such as Figure 21 As shown, create a logical dataset for the database; based on the metadata structure in XSD, create a map sheet metadata table and attribute field structure.

[0058] (2) Create a topology table, such as Figure 22 As shown, it includes: like Figure 23 As shown, a point topology table is created, and an attribute structure is created, including: Geometric Unique Identifier (RCID) and geometric fields.

[0059] like Figure 24As shown, create a curve topology table and an attribute structure, including: Geometric Unique Identifier (RCID), geometry field, and associated reference record field (endpoint reference).

[0060] like Figure 25 As shown, create a composite curve table and an attribute structure, including: Geometric Unique Identifier (RCID) and Associated Reference Record Field (Curve Reference).

[0061] like Figure 26 As shown, create a surface table and an attribute structure, including: a geometrically unique identifier (RCID) and an associated reference record field (curve reference or composite curve reference).

[0062] (3) Create a feature table, such as Figure 27 As shown, this includes: creating chart feature tables sequentially in the logical dataset based on the XSD feature list, and simultaneously creating attribute structures. If the attribute is tidal current information, it is set to character type with a length of 1000. For each feature table, corresponding feature-feature relationship tables and feature-topology relationship tables are created. If the element represents a depth point feature, point geometry attributes and depth value attributes are created simultaneously.

[0063] (4) Create an information type table, such as Figure 28 As shown, this includes: creating information type tables sequentially in the logical dataset based on the XSD information type list; and creating corresponding information type-feature relationship tables and information type-topology relationship tables for each information table.

[0064] (5) such as Figure 29 As shown, copy the catalog of marine obstacle thematic map representations to the resource catalog of the basic geographic information platform. After starting the basic geographic information platform, it will be automatically loaded and used.

[0065] Step 5: Based on the aforementioned relational database table structure, create nautical chart product data using the basic geographic information platform. The steps for creating marine obstacle thematic map products are as follows: (1) such as Figure 30 and 31 As shown, a marine obstacle thematic map project is created, and the product name is defined as 101C100000000. An electronic chart cache structure is constructed, displaying the logical structure in the form of layers. Layers include: points, curves, composite curves, surfaces, cable area features, submarine cable area features, reef / submersible reef features, shipwreck features, etc. The attribute records are in JSON structure.

[0066] (2) such as Figure 32 As shown, set the product information for 101C100000000 yuan.

[0067] (3) such as Figure 33 , 34As shown in Figures 35, 36, and 37, the features of the cable area are drawn and stored in the feature catalog as follows: cable area feature RCID 94, surface RCID 2, combined curve RCID 2, and associated curve RCID 936.

[0068] (4) such as Figure 38 , 39 As shown in Figure 40, draw a linear submarine cable and store it according to the feature catalog as follows: submarine cable feature RCID is 59, curve RCID is 906, and set the sub-attribute text of the information complex attribute to "optical cable".

[0069] (5) such as Figure 41 , 42 As shown in Figure 43, point-based shipwrecks are drawn and stored according to the feature catalog as follows: shipwreck feature RCID is 34, point RCID is 66, and the shipwreck report time is set to "2009----".

[0070] (6) Perform the operation as described in (3), (4), and (5) above, such as Figure 44 , 45 Continue drawing the remaining elements such as offshore platforms, subsea pipelines, and reefs, as shown in Figures 46 and 47, to complete the drawing of all marine obstacle thematic map elements.

[0071] like Figures 34-43 In the map title, "Feature Table," "Topology Table," "Information Type Table," and "Feature and Information Type Relationship Table" should all be enclosed in quotation marks. These types of tables can be used in conjunction with... Figure 2 The content in the model corresponds to this.

[0072] Step 6: The platform calls the LUA script to dynamically select symbols based on feature attributes and exports the data as a 101C100000000.000 file, generating a marine obstacle thematic map conforming to IHO standards. This map can then be opened and viewed in third-party nautical chart software.

[0073] It should be emphasized that the embodiments described in this invention are illustrative rather than limiting. Therefore, this invention includes, but is not limited to, the embodiments described in the specific implementation. Any other implementations derived by those skilled in the art based on the technical solutions of this invention are also within the scope of protection of this invention.

Claims

1. A dynamic modeling method for electronic nautical chart products, characterized in that, Includes the following steps: Step 1: Perform domain analysis on the current electronic chart product, identify relevant terms, and search for corresponding concepts in the pre-set concept dictionary; if they exist, proceed to Step 2; if they do not exist, register the new concept and its semantic definition in the concept dictionary, and then proceed to Step 2. Step 2: Based on the concept dictionary, extract elements, attributes, information types and relationship names, configure the attribute set, allowed spatial geometry types, semantic relationships between elements and the association between information and objects for each element, and save the configuration results as an XML format element catalog file; Step 3: Construct a graphic representation catalog based on the feature catalog described in Step 2. The graphic representation catalog includes: point symbols described in SVG files, line types and polygon fill patterns described in XML files, and graphic representation rules written in a scripting language. The graphic representation rules determine the symbol mapping relationship based on feature attribute values, geometric types, and context parameters. Step 4: Embed the feature catalog and graphic representation catalog into the basic geographic information platform, parse the feature catalog to generate the corresponding XSD structure file, and dynamically create a relational database table structure based on the XSD; Step 5: Based on the created database structure, realize the creation or batch import of electronic nautical chart data; Step 6: The platform loads the parsed nautical chart data, calls the graphic representation rules to return symbol definitions and parameters, and completes the visualization rendering that conforms to the electronic nautical chart standard.

2. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, The concept dictionary in step 1 includes: a list of nautical chart products, a list of element types, a list of simple attributes, a list of complex attributes, a list of attribute value ranges, a list of information types, and a list of association rules. It supports user-defined expansion and can be used for rapid modeling of new nautical chart products.

3. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, In step 3, the graphical representation of linear and planar features adopts a composite symbol method, including line type, line color / planar fill color, and auxiliary symbols inserted along the line, and their combination rules are defined through an XML file.

4. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, The database structure created in step 4 includes: a nautical chart meta-information table, a topology table, various element tables, an information type table, an element-topology relationship table, an element-element relationship table, an element-information type relationship table, and a topology-information type relationship table.

5. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, The data import process in step 5 includes: parsing the original nautical chart data to construct a memory cache structure, sequentially writing metadata, geometric objects, feature instances and relationships into the corresponding database tables, and establishing reference relationships between features and geometry.

6. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, The graphical representation rules in step 4 are implemented using the LUA scripting language, which supports conditional judgment, loop control and function calls, and dynamically selects symbol style, color, display level and drawing priority based on attribute values ​​or context parameters.

7. The dynamic modeling method for electronic nautical chart products as described in claim 1, characterized in that, The relationship types in the feature catalog in step 4 include: additional information association, spatial quality association, and aggregation relationship, which are used to bind features with non-spatial information, quality descriptions, and logical groupings.

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