CURSO Inspire INSPIRE. SPEAKER: Pablo Echamendi Lorente. JEUDI 23/ THURSDAY 23 rd W S V : G E O S P A T I A L D A T A A C C E S S

Transcription

1 CURSO Inspire JEUDI 23/ THURSDAY 23 rd SPEAKER: Pablo Echamendi Lorente

2 WS 5 SCHEDULE WMS OVERVIEW ACTIONS OGC SPECIFICATIONS OTHER SERVICES

3 OVERVIEW proposal: Member States shall establish and operate a network of the following services: (a) discovery services...; (b) view services making it possible, as a minimum, to display, navigate, zoom in/out, pan, or overlay spatial data sets and to display legend information and any relevant content of metadata; (c) download services, enabling copies of complete spatial data sets, or of parts of such sets, to be downloaded; (d) transformation services, enabling spatial data sets to be transformed; (e) invoke spatial data services services, enabling data services to be invoked.

4 OVERVIEW Internet: Expectations for ready access to geospatial information through a common web browser. Users work with different GIS software, earth imaging, database software vendors, etc. OGC: Developed a non-propietary web mapping approach based on the concept of interoperability. OGC Web Map Server Interfaces Implementation Specification offert a way to enable the visual overlay of complex and distributed GI (maps) simultaneously, over the Internet.

5 WMS OVERVIEW Web Map Service Overview: Produces maps of georeferenced data. A map is an image (i.e., JPEG, GIF) depicting vector and/or raster features as symbolized graphics located within a specific bounding box and spatial reference system. This map may represent several layers of data. Maps that share similar geographic space from disparate servers and application software can be overlaid in a WMS Viewer. This is not to be confused with the Web Feature Server (WFS), which allows feature streaming.

6 WMS OVERVIEW ArcIMS WMS DOQ MapInfo WMS Hydro Intergraph WMS Parcels WMS Viewer Client

7 WMS OVERVIEW Navarra Cadastre Navarra orthoimagery Navarra Hydrography GeodB IDENA WMS Viewer Client

8 WMS ACTIONS Web Mapping Actions: A client makes request to one or more Service Registries to discover URLs of WMS containing desired data. Service Registries return URLs and also information about methods by which the discovered data can be accesed. The client locates one or more servers containing the desired data and invokes them simultaneously. Each Map Server accesses the information requested from it and renders it suitable for displaying as one or more layers in a map composed of many layers. Map Servers provide the display-ready information to the client which then display it.

9 WMS INTERACTION Interaction web map client catalogue and map servers:

10 WMS OGC OpenGIS WMS specification: Defines 3 interfaces that support Web Mapping: GetMap(required): specifies map request parameters that allow multiple servers to produce different map layers for a single client. GetCapabilities(required): explains what a map server can do. GetFeatureInfo(optional): specifies how to ask for more information about web map features. Ampliamente superado por la especificación Web Feature Server. Request must come using Get Protocol through HTTP

11 WMS GETCAPABILITIES GetCapabilities URL Component Description VERSION=1.1.1 URL Prefix of server Request Version REQUEST=GetCapabilities Request Name

12 WMS GETCAPABILITIES GetCapabilities abilities&version=1.1.1&service=wms Base?REQUEST=GetCapabilities&version= S.aspx?VERSION=1.1.0&REQUEST=GetCapabilities&SERV ICE=WMS Request Version

13 WMS GETMAP URL Component Description URL Prefix of server VERSION=1.1.1 REQUEST=GetMap FORMAT=image/gif WIDTH=640 Request Version Request Name of WMS operation Output format of map picture Width in pixels of map picture HEIGHT=480 LAYERS=temperature SRS=EPSG:4326 Height in pixels of map picture Comma separated list of one or more map layers Spatial Reference System BBOX=-110,40,-80,30 Minx, Miny, Maxx, Maxy

14 WMS GETMAP URL Component Description TRANSPARENT= true/false (default=false) BGCOLOR= bgcolor_value EXCEPTIONS= exception_format TIME=time Hexadecimal red-green-blue color value for the background color (default=0xffffff) The format in which exceptions are to be reported by the WMS (default=se_xml) Time value of layer desired ELEVATION=elevation Vendor-specific parameters SLD= styledlayer_descriptor_url WFS= web_feature_service_url Elevation of layer desired Optional experimental parameters URL of Styled Layer Descriptor (as defined in SLD Specification). URL of Web Feature Service providing features to be symbolized using SLD

15 WMS GETMAP WMS supports overlay of image files to create a composite map For example, a WMS client may getmap from multiple WMS servers using the same: bounding box (bbox) Spatial Reference System (srs) output size (width and height) Use the transparency parameter to control showing of lower maps

16 GetMap WMS GETMAP &VERSION=1.1.1&FORMAT=image/jpeg&LAYERS=6,1,59 &STYLES=&SRS=EPSG:23030&BBOX=437615, , , &WIDTH=500&HEIGHT=260 Request Version Format Layers SRS Bbox Width Height

17 GetMap WMS GETMAP vicename=133urban&version=1.1.1&request=getmap&srs =EPSG:4326&width=1000&height=500&format=image/jp eg&bbox=-77.02,38.885, ,38.895&layers=UA_ORTHO_Washington01& Request Version Format Layers SRS Bbox Width Height

18 WMS GETMAP A Spatial Reference System (SRS) defines how coordinates are represented in a particular projection (e.g., relate x coordinate to longitude and y to latitude) The SRS namespace invokes codes maintained by the European Petroleum Survey Group (EPSG) Example SRS Code: EPSG:4326 WGS84 datum BBox values are decimal degrees of longitude and latitude, in order of West, South, East, North Longitude values range from 180 to 180 Latitude values range from -90 to 90 An example GetMap for the whole earth SRS=EPSG:4326 and BBOX = -180, -90, 180, 90

19 WMS GETMAP Other parameters Time parameter-spanish Cadastre Cadastral cartography historic service TIME = YYYY-MM-DD Example: 23th october MS/ServidorWMS.aspx?[...]TIME= &[...].

20 WMS GETMAP GetMap Base?REQUEST=GetMap&VERSION=1.1.1&SRS=EPSG:4326&BBO X=- 18.2,27.36,4.4,43.81&WIDTH=549&HEIGHT=400&LAYERS=Todas &STYLES=default&FORMAT=image/jpeg&BGCOLOR=0xFFFFFF&TR ANSPARENT=FALSE&EXCEPTIONS=application/vnd.ogc.se_.xml Request Version Format Layers SRS Bbox Width Height Bgcolor Transparent Exceptions

21 EXERCISE GetMap exercisess Change Layer=Unidades_administrativas) Change bgcolor=0xdddddd Change layer=relieve Change WIDTH=100&HEIGHT=300 Change FORMAT=jpeg (png,gif) Change BBOX=1,37.98,4.6,40.6 (Balearic Islands) Change SRS=EPSG:23030&BBOX= , , , Change layer=bcn and see exceptions messages in different formats (xml, inimage)

22 WMS GETFEATUREINFO WMS service application: get information about web map features. Example: get information about cadastral reference information: html file

23 WMS-SLD OpenGIS Styled Layer Descriptor (SLD) Implementation Specification The SLD is an encoding for how the Web Map Server (WMS 1.0 & 1.1) specification can be extended to allow user-defined symbolization of feature data. Enhancements to WMS GetCapabilities Does the WMS provide SLD support? EST=GetMap&SRS=EPSG:4326&BBOX=0.0,0.0,1.0,1.0&S LD=http%3A%2F%2Fmyclientsite.com%2FmySLD.xml& WIDTH=400&HEIGHT=400&FORMAT=PNG

24 OTHER SERVICES WFS WCS DOWNLOAD TRANSFORMATION WFS-G COMBINED SERVICES

25 OTHER SERVICES WFS A Web Feature Service allows a client to perform data manipulation operations on a set of geographic features. Data manipulation operations include the ability to: 1.Get or Query features based on spatial and nonspatial constraints. 2.Create a new feature 3. Delete a feature 4. Update a feature

26 OTHER SERVICES WFS operations: GetCapabilities: A web feature server must be able to describe its capabilities. Specifically, it must indicate which feature types it can service and what operations are supported on each feature type. DescribeFeatureType : A web feature server must be able, upon request, to describe the structure of any feature type it can service. GetFeature: A web feature server must be able to service a request to retrieve feature instances. In addition, the client should be able to specify which feature properties to fetch and should be able to constraint the query spatially and non-spatially. Transaction: A web feature server may be able to service transaction requests. A transaction request is composed of operations that modify features; that is create, update, and delete operations on geographic features. LockFeature: A web feature server may be able to process a lock request on one or more instances of a feature type for the duration of a transaction. This ensures that serializable transactions are supported.

27 OTHER SERVICES WCS The Web Coverage Service (WCS) provides access to intact, raw data such as imagery, digital elevation matrix (DEM) and other types of gridded data. Unlike the Web Map Service (WMS), which returns static maps, the Web Coverage Service provides only data access. Typically client-side applications will model, analyze and render the data.

28 OTHER SERVICES DOWNLOAD Example: IDENA Example: IDERIOJA

29 OTHER SERVICES TRANSFORMATION Web Coordinate Transformation Service (WCTS) A WCTS allows the web-based transformation of geographic coordinates from one coordinate references system into another.

30 OTHER SERVICES WFS-G Web Gazetteer Service Service allowing geo-referencing of geographic entities based on textual identifiers (e.g. place names). Example IDEE

31 OTHER SERVICES COMBINED SERVICES Cadastre on Google Earth TF5369S

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