The Data on the Web Best Practice (DWBP) provide a set of recommendations that are applicable to the publication of all types of data on the Web. Those best practices cover aspects including data formats, data access, data identifiers, metadata, licensing and provenance.
The Spatial data on the Web Best Practice extends the DWBP and gives best practices related to the publication of spatial data on the Web; the use of Web technologies as they may be applied to location. The best practices presented here are intended for practitioners, including Web developers and geospatial experts, and are compiled based on evidence of real-world application. These best practices suggest a significant change of emphasis from traditional Spatial Data Infrastructures by adopting an approach based on general Web standards.
When publishing datasets, it is a good idea to publish a dataset description along with it. In the eGovernment sector, DCAT vocabulary is a standard for dataset metadata publication and harvesting implemented by data portals.
To query data using spatial operators, the OGC standard GeoSPARQL offers a query language for RDF data, including the following set of operators: equal, disjoint, touches, within, overlaps, crosses, intersects, contains.To use spatial and temporal information with OpenSearch, a collection of simple formats to share search results, the OGC standard OpenSearch Geo and Time Extensions is available.
To visualize heterogeneous 3D geospatial data on the Web in an efficient way, Indexed 3D Scene Layers (i3S) can be used. In i3S, 3D data can be partitioned into arbitrarily large containers called "Scene layers". Each layer has its own behavior and properties. i3S is based on REST, JSON and other Web standards.
|Feature||Specification / Group||Maturity||Current implementations|
|Data on the web guidelines||Data on the Web Best Practices|
Data on the Web Best Practices Working Group
|Spatial data on the web guidelines||Spatial Data on the Web Best Practices|
Spatial Data on the Web Working Group
|Dataset description||Data Catalog Vocabulary (DCAT)|
Government Linked Data Working Group
|Spatial query||GeoSPARQL - A Geographic Query Language for RDF Data|
|OpenSearch Geo and Time Extensions|
|3D tiling||Indexed 3D Scene Layers|
Specifications in progress
The Statistical Data on the Web Best Practices is a Note currently being written by the Spatial data on the Web interest group (SDWIG). Like the Spatial Data on the Web Best Practices, this Note will be a specialization of the more general Data on the Web Best Practices Recommendation, offering guidance on sharing statistical data. The aim of the work is to provide guidance on how statistical data can be made to work more effectively as part of the overall Web of Data. While not restricted to the geospatial aspects of statistical data, the relation between statistical and spatial considerations will be given particular emphasis.
A new version of the OGC standard Web Feature Service (WFS) is being developed at the Open Geospatial Consortium (OGC) for querying geospatial information on the web. It is a complete rewrite of previous versions, focusing on a simple RESTful core specified as reusable OpenAPI components with responses in JSON and HTML.
For publishing, partitioning and streaming massive heterogeneous 3-dimensional geospatial datasets, Cesium 3DTiles is available. It is currently in the process of becoming an OGC community standard.
|Feature||Specification / Group||Maturity||Current implementations|
|Statistics guidelines||Statistical Data on the Web Best Practices|
Spatial Data on the Web Interest Group
|Dataset description||Data Catalog Vocabulary (DCAT) - Version 2|
Dataset Exchange Working Group
|Access to spatial things||OGC Web Feature Service 3.0|
|3D tiling||3D Tiles|
Although work has not started, it is the intention of the SDWIG to produce an SSN Primer which will explain how best to use the SOSA and SSN vocabularies.
Although work has not started, the SDWIG may produce a Sensors and observations Note, giving an overview of the standards landscape related to sensors and observations (such as the Generic Sensor API family, the WoT family, SSN, SensorThings API etc) that explains the scope of each of these standards, their application to practical use cases and mechanisms by which they may be combined.
Because DCAT is lacking in possibilities for describing some specific characteristics spatial datasets, an application profile for spatial data, GeoDCAT-AP has been developed in the framework of ISA Programme of the European Union, with the primary purpose of enabling the sharing of spatial metadata across domains and catalogue platforms. It defines RDF bindings covering metadata standards from the geospatial domain, enabling the harmonized RDF representation of existing spatial metadata.
Map Markup Language (MapML) is an HTML- and DOM-compatible hypertext format for declaratively representing 2D map layers with embedded or linked tile, image and vector features, designed after the architectural style of the Web, by paving the cowpaths of Web mapping. Map layers may be used individually or stacked using custom elements or other standard Web technologies (browsers), to compose a complete map. MapML uses links and forms to integrate standard OGC technologies into the fabric of the Web 'without programming'.
Vector tiling is a name for solutions where geographic data is packaged into pre-defined roughly-square shaped tiles for transfer over the web. There are several existing solutions, none yet standardized. The most well known specification is Mapbox Vector Tiles.
|Feature||Specification / Group||Implementation intents|
|Spatial dataset description||GeoDCAT-AP: A geospatial extension for the DCAT application profile for data portals in Europe. Version 1.0.1|
|Present a view||Map Markup Language|
Maps for HTML Community Group
|Geospatial data partitioning||Mapbox Vector Tiles|
Features not fully reviewed
These features are established standards in the geospatial domain, and of possible interest to the Web community, but are not fully reviewed as to their compliance to modern Web architecture.
- Web Map Service (WMS)
- An OGC standard for access to data rendered as a map. The requests are standardized XML messages.
- Web Map Tile Service (WMTS)
- An OGC standard for access to data rendered as a map, using tiling for better performance. The requests are standardized XML messages.
- Web Coverage Service (WCS)
- An OGC standard for access to multi-dimensional coverage data. The requests are standardized XML messages.
- Web Processing Service (WPS)
- An interface standard which provides rules for standardizing inputs and outputs (requests and responses) for invoking spatial processing services, such as polygon overlay, as a Web service.
- Catalog Services (CSW)
- An OGC standard for publishing and searching collections of descriptive information (metadata records) for geospatial data, services, and related information.