CN101561816A - Method for releasing geospatial data incremental information - Google Patents

Abstract

The invention discloses a method for releasing geospatial data incremental information, which comprises the following steps: determining the semantic definition, classification, measurement and storage of the incremental information by organizing and modeling geographic incremental information; establishing an XML-based geographic incremental information storage medium which facilitates the release of the geographic incremental information and the update of a client; and storing the acquired incremental information in an XML format and releasing the XML incremental information. The method provides a database operation-oriented data description of the incremental information according to the change type and operation type of factors as well as the classic definition and classification of the incremental information, provides incremental information data expression in XML on the basis of geographic information data file expression and SGML expression, provides XML-based geographic incremental information storage, and has the advantages of self-description, flexibility, independence, expandability, high structural property and good cross-platform property.

Description

Method for Publishing Incremental Information of Geospatial Data

technical field

The invention relates to a method for releasing geographic data incremental information, and belongs to the technical field of geographic information.

Background technique

With the expansion of the field of spatial data services and the continuous deepening of applications, users have put forward higher requirements for the accuracy, integrity and currentity of spatial data. Therefore, it has become a top priority for spatial data producers to continuously update geospatial databases, improve the current status of geospatial data, and distribute updated information to data users.

According to the data content provided to its users, existing update services can be divided into batch update and incremental update. Batch update provides users with all the content of the new version of data. This update method has many problems such as low transmission efficiency and difficulty in user-side update, while incremental update only provides customers with changed information. This update method is more scientific. It is a more effective update information release strategy. At present, the research on updating incremental information is still in its infancy, and there are many problems that need to be further studied in both theory and method.

Contents of the invention

The purpose of the present invention is to provide a method for publishing incremental information, which saves the incremental information of geographical data in XML format and releases it. In this way, a more efficient data update method than the previous batch update is realized.

Technical scheme of the present invention comprises the following steps:

Step 1: Formulate incremental information classification standards and determine incremental information classification metrics. Different types of spatial data are classified based on different spatial attributes, and different types of changes are based on different degrees of change.

Step 2: Model the incremental information according to the incremental information classification standard, store the obtained geographical incremental information in the XML document, and obtain the XML incremental information.

Step 3 publishes the XML incremental information.

The above-mentioned incremental information classification standards and metrics of geospatial data are the premise and basis for incremental information extraction. Geographic incremental information is related to snapshots, events, and snapshot differences. Snapshots refer to the data expression of elements in the objective world at a certain moment. Events are the cause of snapshot differences. Snapshot differences reflect the degree of difference in geographic information caused by events. Increment Information is a composite of snapshot differences and events.

Basic geographic information includes three aspects: geographic semantics, geometric shape and features, and thematic attributes. At the same time, geographic elements are classified according to point, line, and surface geometric features. Events are used to describe the changes of geographical elements in the real world. According to the changes in the semantics, geometry and attributes of geographic information, the change events of the target can be described as follows: the displacement of point elements, the change of semantics and thematic attributes; the extension and shortening of line elements , deformation, displacement, semantic and thematic attribute changes; expansion, contraction, deformation, displacement, semantic and thematic attribute changes of surface elements. According to the geographic coding, geometric description, and thematic features of specific geographic information (such as basic geographic information), specific parameter descriptions and measurements can be made on the above classification standards to provide a basis for subsequent incremental information extraction.

The invention describes the incremental information of geographic data through XML documents, stores them on the server side, and according to the user's request and customization, the Web server complexly parses and inquires the XML documents, and returns relevant information to the user side for users to browse and use. Realize the release of incremental information of geospatial data. The Web server accepts the service request from the client, and according to the client's request, sends the incremental data XML analysis and query instructions to the data server, completes the extraction of incremental information from the database, generates an XML-based incremental information description file for transmission, and then Design the style sheet file XSL for the incremental information file, and finally send the XML file and the corresponding XSL style sheet file to the client.

The data server completes the warehousing and updating of version data, and provides data sources for users' query and display.

According to the change type and operation type of elements, and the typical semantics and classification of incremental information, the invention proposes the data description of incremental information oriented to database operation; on the basis of geographic information data text expression and SGML expression, it proposes to use XML to express incremental information. Incremental information data; also proposed a service framework based on XML incremental information release. XML-based geographic incremental information storage has the advantages of self-description, flexibility, independence, scalability, strong structure, and good cross-platform.

Description of drawings

Figure 1 is a comparison diagram of event types and operations in the database.

Figure 2 is a flow chart of incremental information release.

Detailed ways

及ΔGeo为快照差项，其中ID_old，ID_new分别为地理目标在旧、新版本中的标识，

表示地理目标专题属性变化的集合，ΔGeo表示地理目标的几何变化，Operate则是隐含现实世界事件的数据库更新操作。In order to facilitate the update of the client database, the present invention proposes a database operation-oriented incremental information definition based on event and snapshot difference types, which implies various events in the objective world. The incremental information based on operation and snapshot difference is recorded as ΔObject, ΔObject=[Diff, Operate], snapshot difference $\mathrm{Diff}=\{\mathrm{ID}\_\mathrm{old},\mathrm{ID}\_\mathrm{new},\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\∪}}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo}\}.$ ID_old, ID_new,

and ΔGeo are snapshot difference items, where ID_old and ID_new are the identifiers of geographic objects in the old and new versions respectively,

Indicates the collection of thematic attribute changes of geographic objects, ΔGeo represents the geometric changes of geographic objects, and Operate is the database update operation that implies real-world events.

According to the corresponding relationship between the event type and the operation in the database, as shown in Figure 1.

When the events of "Appearance", "Disappearance", and "Geometry or attribute change" occur on a single object, the three basic operations corresponding to the database are: add, delete, and modify. When the events of "merge", "split" and "many-to-many" occur on multiple geographic objects, the complex operations can be decomposed into the above three basic operations, that is, the deletion of the original geographic object and the addition of a new geographic object. Among them, the event "geometric or attribute change" has different meanings for different geographic feature classes. The geometric or attribute changes corresponding to different feature types are shown in the following table:

Element type Cases where geometry or attributes change point element Displacement, attribute change line feature Extension, shortening, deformation, displacement, attribute change Surface elements Expansion, contraction, deformation, displacement, property change

The incremental information caused by various events can be expressed as:

When a single geographic object appears, $\mathrm{\Δ\; Object}\left(\mathrm{insert}\right)=[\mathrm{ID}\_\mathrm{new},\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\∪}}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},\mathrm{insert}].$

When a single geographic object dies, $\mathrm{\Δ\; Object}\left(\mathrm{Delete}\right)=[\mathrm{ID}\_\mathrm{old},\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\∪}}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},\mathrm{Delete}].$

When a single geographic object geometry or attribute changes, $\mathrm{\Δ\; Object}\left(\mathrm{Modify}\right)=[\mathrm{ID}\_\mathrm{old},\mathrm{ID}\_\mathrm{new},\underset{i=1}{\overset{\mathrm{no}}{\∪}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},\mathrm{Modify}].$

When multiple geographic targets are combined, $\mathrm{\Δ\; Object}\left(\mathrm{Merge}\right)=[\mathrm{ID}\_\mathrm{ol}{d}_1,\mathrm{ID}\_\mathrm{ol}{d}_2,\&Center\; Dot;\&Center\; Dot;\&Center\; Dot;,\mathrm{ID}\_\mathrm{ol}{d}_m,$ $\mathrm{ID}\_\mathrm{new},\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\∪}}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},\mathrm{Merge}]=$ $\mathrm{\Δ\; Object}{\left(\mathrm{Delete}\right)}_1+\mathrm{\Δ\; object}{\left(\mathrm{Delete}\right)}_2+\·\·\·+\mathrm{\Δ\; Object}{\left(\mathrm{Delete}\right)}_m+\mathrm{\Δ\; Object}\left(\mathrm{insert}\right).$

When geographic targets are split, $\mathrm{\Δ\; Object}\left(\mathrm{split}\right)=[\mathrm{ID}\_\mathrm{old},\mathrm{ID}\_{\mathrm{new}}_1,\mathrm{ID}\_{\mathrm{new}}_2,\·\·\&Center\; Dot;,$ ${\mathrm{ID}\_\mathrm{new}}_N,\underset{i=1}{\overset{\mathrm{no}}{\∪}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},\mathrm{split}]=$ $\mathrm{\Δ\; Object}\left(\mathrm{Delete}\right)+\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_1+\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_2+\&Center\; Dot;\&Center\; Dot;\&Center\; Dot;\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_N.$

When a geo target changes many-to-many, $\mathrm{\Δ\; Object}\left(\mathrm{Mvs}\right)=[\mathrm{ID}\_\mathrm{ol}{d}_1,$ ${\mathrm{ID}\_\mathrm{old}}_2,\·\·\·,{\mathrm{ID}\_\mathrm{old}}_m,\mathrm{ID}\_{\mathrm{new}}_1,\mathrm{ID}\_{\mathrm{new}}_2,\&Center\; Dot;\·\·,{\mathrm{ID}\_\mathrm{new}}_N,\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\∪}}}\mathrm{\ΔAttribute},\mathrm{\ΔGeo},$ $\mathrm{Mvs}]=$ $\mathrm{\Δ\; Object}{\left(\mathrm{Delete}\right)}_1+\mathrm{\Δ\; Object}{\left(\mathrm{Delete}\right)}_2+\·\·\&Center\; Dot;+\mathrm{\Δ\; Object}{\left(\mathrm{Delete}\right)}_m+\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_1$ $+\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_2+\&Center\; Dot;\·\·\mathrm{\Δ\; Object}{\left(\mathrm{insert}\right)}_N.$

The present invention adopts visual and standardized XML-related tools to design an intuitive graphic structure and then generate a physical XML Schema.

The root node of the XML Schema document of the incremental information is the incremental map (ChangeOnlyMap), which is mainly described from the metadata (MetaData) and the update collection (UpdateCollection) of the main data body.

Metadata section:

Metadata (MetaData) can be further divided into the following five aspects: related information of the old version of the map (BeforeUpdateMap), related information of the new version of the map (AfterUpdateMap), information about this data processing (AboutProcessing), and field information sets of feature classes (FieldsInfo) and ChangeStatic.

In BeforeUpdateMap and AfterUpdateMap, its child nodes record the map sheet name (MapSheetName), feature class name (MapSheetName), feature geometry type (Geometry), map producer (MapProducer), map provider (MapProvider) of the old and new maps , map publisher (Release), map release date (ReleaseDate), security level (securitylevel), geographic coordinate system (GeoSystem), elevation reference (elevationbase), projection system (ProjectSystem), map frame standard (MapSheetStandard), frame number (MapSheetNumber), the total number of sheets (MapSheetTotal Number).

In AboutProcessing, its child nodes record the version (Version), developer (Supplier), and publisher (Release) of the system. In FieldsInfo, the field information (Field) of its child node feature class records the field name (Name) and field type (Type).

Main data body part:

UpdateCollection is divided into multiple update data sets (UpdateDataSet) according to its attribute map number (PartitionID), and UpdateDataset records the basic information (BaseInformation) and simple update (SimpleUpdate) according to its attribute feature class name (FeatureClassName). , CompositeUpdate has three child nodes.

The geometric type (ShapeType) and primary key (PrimaryKey) of spatial data are recorded in BaseInformation.

In SimpleUpdate, the total number of simple updates (SimpleTotalNum) and simple update operations (SimpleOperation) are recorded. Among them, SimpleOperation is divided into adding (AddFeature), deleting (DeleteFeature), modifying (ModifyFeature).

In AddFeature, the total number of increases (AddFeatureNum) and the increased operation (AddOperation) are recorded, where AddOperation includes the increased source (Source), [D (FeatureAfterID) of the new target and the geometry and attribute information. The value of Source only includes the following four types: added in split (SplitAdd), pure added (PureAdd), added in merging (CombinationAdd), added in many-to-many (MvsNAdd),

In DeleteFeature, the total number of deletions (DeleteFeatureNum) and the operation of deletion (DeleteOperation) are recorded. DeleteOperation contains the source of deletion (Source), the ID number of the deleted target FeatureBeforeID, and the geometry and attributes of the deleted target FeatureBefore information. Here, the value of Source only includes the following four types: deleted during split (SplitDelete), purely deleted (PureDelete), deleted during merging (CombinationDelete), and deleted during many-to-many (MvsNDelete).

In ModifyFeature, the total number of modifications (ModifyFeatureNum) and the modified operation (ModifyOperation) are recorded, where ModifyOperation includes the modified source (Source), the ID number of the original target (FeatureBeforeID), the geometry and attribute information of the former target FeatureBefore and the ID number (FeatureAfterID) of the new target, the geometry and attribute information of the post-target FeatureAfter. The value of Source here includes the following five types: expansion (Expansion), contraction (Reduction), deformation (Reshape), translation (Move), attribute change (AttributeChange).

In CompositeUpdate, the total number of complex updates (CompositeTotalNum) and complex update operations (CompositeOperation) are recorded. The operation contains three sub-nodes: split (SplitFeature), merge (CombinationFeature), and many-to-many (MvsN).

The total number of target splits (SplitFeatureNum) and the split operation (SplitOperation) are recorded in SplitFeature. The operation records the number of original objects (FeatureOldNum), the ID number of the original object (FeatureOldID), the number of new objects (FeatureNewNum), and the ID number of the new object (FeatureNewID). For each splitting event, FeatureOldID only appears once, while FeatureNewID can appear infinitely.

In CombinationFeature, the total number of targets combined (CombinationFeatureNum) and the combination operation (CombinationOperation) are recorded, where the combination operation records the number of original targets (FeatureOldNum), the ID number of the original target (FeatureOldID), and the number of new targets (FeatureNewNum), the ID number (FeatureNewID) of the new object. For each merge event, FeatureOldID appears infinitely, while FeatureNewID appears only once.

In MvsN, the total number (MvsNFeatureNum) and many-to-many operations (MvsNOperation) of geographical objects are recorded. Among them, the many-to-many operation records the number of original objects (FeatureOldNum), the ID number of the original object (FeatureOldID), the number of new objects (FeatureNewNum), and the ID number of the new sales department (FeatureNewID). For each many-to-many event, FeatureOldID and FeatureNewID can appear infinitely.

The following example shows the many-to-many XML representation of geographical objects, in which two old objects whose IDs are 1650 and 1652 are converted into three new objects whose IDs are 1020, 1021, and 1022 respectively.

<ChangeOnlyMap>

<UpdateCollection PartitionID="h50111101">

<UpdateDataSet FeatureName="Residence">

<CompositeUpdate>

<CompositeTotalNum>1</CompositeTotalNum>

<CompositeOperation>

<MvsN>

<MvsNFeatureNum>1</MvsNFeatureNum>

<MvsNOperation>

<FeatureOldNum>2</FeatureOldNum>

<FeatureOldID>1650</FeatureOldID>

<FeatureOldID>1652</FeatureOldID>

<FeatureNewNum>3</FeatureNewNum>

<FeatureNewID>1020</FeatureNewID>

<FeatureNewID>1021</FeatureNewID>

<FeatureNewID>1022</FeatureNewID>

</MvsNOperation>

</MvsN>

</CompositeOperation>

</CompositeUpdate>

</UpdateDataSet>

</UpdateCollection>

</ChangeOnlyMap>

The invention describes the incremental information of geographical data through the definition of the incremental information through the XML document, and stores it on the server side. According to the user's request and customization, the WEB server complexly parses and queries the XML document, and returns relevant information to the user for browsing and use. The release flow chart is shown in Figure 2. The respective functions of the client and server are as follows:

Client: The client mainly makes spatial data service requests to the WEB server, and analyzes and displays the results returned by the server. Users can customize incremental information according to their own needs. When implementing incremental update, the client only needs to download the xml file describing the incremental information and the client update program to update the client data.

Web server: The Web server is responsible for accepting the client's service request, passing it to the data server, and sending the result back to the client. According to the client's request, the incremental data XML parsing and query instructions are sent to the data server, the incremental information is extracted from the database, and the XML-based incremental information description file for transmission is generated. For the incremental information file, a style sheet file XSL is designed, and then the XML file and the corresponding XSL style sheet file are sent to the client, which is displayed by the parser that comes with the client browser. On this basis, a visual interface and various query functions for user browsing are realized, and a server-side download address is provided for users to download incremental information files.

Data server: The data server completes the warehousing and updating of version data, and provides data sources for users' query and display.

Claims (5)

1. the dissemination method of a geospatial data increment information is characterized in that may further comprise the steps:

Step 1: formulation increment information criteria for classification and definite increment information classification are measured;

Step 2: according to the increment information criteria for classification increment information is carried out modeling, the geographical increment information of gained is stored among the XML document, the XML that obtains increment information expresses;

Step 3: the XML increment information is issued.

2. according to the dissemination method of the described geospatial data increment information of claim 1, it is characterized in that: geographical increment information and snapshot, incident and snapshot difference correlation, snapshot is meant the data representation of key element in objective world sometime, incident is the reason that the snapshot difference produces, the difference degree of the geography information that snapshot difference embodiment incident causes, increment information are the compound bodies of snapshot difference and incident; Basic geography information comprises geographical semanteme, geometric shape and feature and thematic attribute, geographic element is classified key element according to the point, line, surface geometric properties simultaneously, the variation of the geographic element of real world kind is described with incident, according to the variation of semanteme, geometry and the attribute of geography information, the change events that can describe target is as follows: displacement, semanteme and the thematic attribute change of some key element; The prolongation of line feature, shortening, distortion, displacement, semanteme and thematic attribute change; The expansion of face key element, contraction, distortion, displacement, semanteme and thematic attribute change according to geocoding, geometric description and the thematic feature of concrete geography information, are carried out concrete parametric description and tolerance to above-mentioned criteria for classification.

3. according to the dissemination method of the described geospatial data increment information of claim 1, it is characterized in that: the increment information of describing geodata by XML document, be stored in server end, request and customization according to the user, Web server is resolved and is inquired about XML document, return for information about and to give user side, browse and use the issue of realization geospatial data increment information for the user.

4. according to the dissemination method of the described geospatial data increment information of claim 3, it is characterized in that: Web server is accepted the services request of client, request according to client, parsing and query statement to data server incremental data XML, finish and from database, extract increment information, the increment information description document that generation is used to transmit based on XML, design style sheet file XSL for the increment information file then, at last XML file and corresponding XSL style sheet file are sent to client together.

5. according to the dissemination method of the described geospatial data increment information of claim 4, it is characterized in that: data server is finished warehouse-in, the renewal of edition data, for user's inquiry and demonstration provides data source.

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