PF-III User Guide for GUI and API - validation phase

Transcription

1 PF-III User Guide for GUI and API - validation phase Doc.No. : EUM/OPS/MAN/18/ Issue : v1a Date : 7 June 2018 WBS/DB : S EUMETSAT Eumetsat-Allee 1, D Darmstadt, Germany T l EUMETSAT The copyright of this document is the property of EUMETSAT.

2 Document Change Record Issue / Revision Date DCN. No Changed Pages / Paragraphs V1 30/05/2018 First release for user validation purposes V1A 07/06/2018 Revision of access token workflow (new url) Page 3 of 38

3 Table of Contents 1 INTRODUCTION Acronyms and Abbreviations Definitions WHAT IS EUMETSAT WEB MAP SERVICE EUMETSAT WEB MAP SERVICE GRAPHICAL USER INTERFACE Registered and unregistered users Accessing the map viewer Access as Unregistered User Access as a Registered User Maps visualisation as a Registered User Functionalities of EUMETSAT Web Map Service online viewer Help Page Search and add products to the map Get product information Add selected products to the map viewer Image download options Maps Animation Functionalities available ONLY for Registered Users Getting data values for WCS and WFS products Download animation Downloads status Save maps My Views User settings and default landing page EUMETSAT WEB MAP SERVICE API Getting a valid access token for licensed images and data OGC Web Map Service (WMS) Sending requests to a WMS service How to send a GetCapabilities request How to send a GetMap request OGC Web Feature Service (WFS) and Web Coverage Service (WCS) WCS or WFS GetCapabilities request WFS DescribeFeatureType WFS GetFeature WCS DescribeCoverage WCS GetCoverage KNOWN ISSUES FOR EUMETSAT WEB MAP SERVICE GUI Page 4 of 38

4 1 INTRODUCTION This guide provides a short introduction about EUMETSAT Web Map Service, the products available and a detailed description of the WMS Service characteristics and usages available during this validation phase. This service provides a series of licensed and open visualizations to users, through a modern Web User Interface and through APIs based on international standards. In particular, the main characteristics of this service are: The provision of online access to products images (and to numerical data for selected products) through international standard interfaces: Web Map Service (WMS), Web Coverage Service (WCS) and Web Feature Service (WFS); The provision of near real-time online access to different EUMETSAT Products (Meteosat 0 degree products, Rapid Scan MSG Level 1.5 products, RGB products, Metop products) and Sentinel-3 products images in full spatial resolution and a time archive of 6 months, allowing users to go back in time and access/download those images; A GUI offering different functionalities like: data availability representation, time based navigation, multi-layer composition, maps re-projection, maps sharing, and product animation. The Provision of search and discovery functionality in the GUI and in the API (through OGC Web Services) The provision of tailoring capabilities for the GUI, allowing users to customize their maps through the use of the so-called Views within their profile (see for Views explanation); The provision of well know data formats (different type of formats according to the type of accessed product: GeoTIFF, PNG, KMZ, GeoJSON, Shapefile, NetCDF); The provision of different GUI functionalities and access produts according to the type of user. Page 5 of 38

5 1.1 Acronyms and Abbreviations Acronym API ASCAT EO Portal GEO GIS GUI LEO MSG OGC QGIS SST URL WCS WFS WMS Definition Application Programming Interface Advanced Scatterometer data products EUMETSAT Earth Observation Portal Geostationary Orbit Geographic Information System Graphical User Interface Low Earth Orbit Meteosat Second Generation Open Geospatial Consortium Quantum GIS Application Sea Surface Temperature Uniform Resource Locator Web Coverage Service Web Feature Service Web Map Service 1.2 Definitions Registered users Unregistered users Users holding access credentials and a valid licence for access to licensed EUMETSAT visualisation and data. Users who without access credentials (these users only have access to non-licensed, open, visualizations). Page 6 of 38

6 2 WHAT IS EUMETSAT WEB MAP SERVICE The EUMETSAT Web Map Service allows users to access a selection of Meteosat, Metop and Sentinel-3 products (as imagery or numerical data) in near-real-time through an OGC Web Map Service protocol, using both APIs and an interactive tool (Figure 1) at the following address: The products that can be accessed from EUMETSAT Web Map Service are: Rapid Scan SEVIRI (Single Channel IR3.9 and RGB products: Airmass, Natural Colour, Day Microphysics), European HRV RGB (High Resolution Visible channel SEVIRI) E-View, Meteosat 0 Degree Visualised Product MPE, and RGB products: Airmass, Natural Colour, RGB Microphysics), Metop ASCAT Coastal Winds at 12.5 km Swath Grid Visualisation, Sentinel 3 Sea Surface Temperatures (SST). Figure 1: EUMETSAT Web Map Service map viewer EUMETSAT Web Map Service implements the OGC (Open Geospatial Consortium) Web Map Service Interface Standard (WMS) and can be used to request and access archive products in GIS clients supporting OGC WMS Besides, some products are also provided through OGC WCS (Web Coverage Service) and WFS (Web Feature Service). The earth observation (EO) imagery and data provided by EUMETSAT Web Map Service are delivered by satellites having different orbit types, which affects the spatial coverage and spatial/ temporal resolution of the produced products. The two orbit types are: Page 7 of 38

7 Geostationary Orbit (GEO): satellites (e.g. Meteosat Second Generation - MSG) are positioned at a fixed point over the equator and rotate in sync with the earth. Because of the high altitude produced images cover the whole visible Earth disc. Resolution is >=1km. Geostationary orbits are of great importance for weather monitoring because these satellites can provide a constant view of the same surface area. Low Earth Orbit (LEO): satellites (e.g. Metop or Sentinel-3) go around the Earth in a polar orbit, passing the poles as they circle the Earth. The lower altitude compared to GEO satellites produces images that cover only part of the Earth (swath based). Page 8 of 38

8 3 EUMETSAT WEB MAP SERVICE GRAPHICAL USER INTERFACE This paragraph describes how users can access products via the EUMETSAT Web Map Service GUI and how it is possible to interact with the online map viewer and its functionalities in order to display images and data. Functionalities and access to products are diversified according to user s access rights and license. 3.1 Registered and unregistered users Unregistered users have access only to non-licensed (open) visualizations of EUMETSAT Web Map Service, i.e.: Multi-Sensor Precipitation Estimate (JPEG) - MSG - 0 degree Airmass RGB - MSG - 0 degree Natural Colour RGB - MSG - 0 degree Day Microphysics RGB - MSG - 0 degree Registered users can access more functionalities with respect the unregistered users: Create and edit their own views and save them in the My Views section. Set their default View. Share the created views with other users. Download maps animation. 3.2 Accessing the map viewer The map viewer can be accessed at this link: Access as Unregistered User When a user accesses the service as an unregistered user, the available map viewer functionalities and products are displayed in Figure 2. The map viewer shall display one or more products as example (in the case of the figure below, Airmass RGB - MSG - 0 degree and Multi-Sensor Precipitation Estimate (JPEG) - MSG - 0 degree). Page 9 of 38

9 Figure 2: EUMETSAT Web Map Service Graphical User Interface (as unregistered user) The interactive map viewer is divided in different sections: 1. Default view: a. Add layers, b. Map view settings, c. Loaded products. 2. Product Search. 3. User Login. 4. Help Page. 5. Map Zoom. 6. Download current map view. 7. Animation manager. 8. Time manager: a. Time picker, b. Previous/next timestep, c. Expand/compress timeline, d. Time slider, e. Change time scale Access as a Registered User In order to access the service as a registered user, click on the icon on the top right of the page, as shown in Figure 3 and add the access credentials issued by EUMETSAT. Page 10 of 38

10 Figure 3: User Login When the user clicks on Login button, the page is redirected to dummy EUMETSAT EO Portal login screen Maps visualisation as a Registered User When accessing EUMETSAT Web Map Service as a registered user, it is possible to access to additional functionalities (see Figure 4). Page 11 of 38

11 Figure 4: EUMETSAT Web Map Service Graphical User Interface as registered user (dedicated functionalities in orange) The interactive map viewer is divided in different sections (additional functionalities for registered users are highlighted in the list): 1. Default view: a. Load next/previous view, b. Map view settings, c. Save map view, d. Add layers, e. Loaded products. 2. Access to user s saved Views. 3. Product Search. 4. Download status. 5. User settings and logout. 6. Help Page. 7. Map Zoom. 8. Download current map view. 9. Animation manager. 10. Time manager: a. Time picker, b. Previous/next timestep, c. Expand/compress timeline, d. Time slider, e. Change time scale. 3.3 Functionalities of EUMETSAT Web Map Service online viewer Help Page It is possible to access the Help Page through the button. This will open a web page where it is possible to send feedbacks, find legal information, and find technical information about the service, technical documents and the User Guide for GUI and API Search and add products to the map In order to search products in the available archive (or discover the complete list of available products), the user can use the Product Search button or the Add layer button (Figure 5). Page 12 of 38

12 Figure 5: Search and add new products in the map Clicking on one of these buttons, a new window opens, in which it is possible so search and discover for archive products. Products are grouped in different categories (please, note that a product can be included in more than one category), which in turn are divided in subcategories. The list of products can be visualized as Tiles or as a Tree (see Figure 6). Let s for example add a Meteosat Second Generation product to the map viewer. It is possible to access the available products of MSG clicking on Mission and then on Meteosat Second Generation (see Figure 6). Figure 6: Product result visualization (tiles or tree view) Resulting products (Figure 7) are listed with their name and a thumbnail, plus two icons in the lower right that allow the user to take different actions: Get information about the product. Add directly the product on the map viewer. The lock icon indicates that only registered users can access this product. Page 13 of 38

13 Figure 7: Search and add new products in the map Get product information It is possible to get information about the product clicking on the thumbnail or on the button. Once the user accesses the information page for a product, the page is divided in two different tabs: Description and Data Access (see Figure 8). In the Description tab it is possible to find a brief description of the product, additional information (Time range, Last acquisition time, and Geographical extent), the button to add the product to the map viewer and the button to open the related page of the Product Navigator. In the Data Access tab two URLs are provided: the first one is the URL to the GetCapabilities of the product, the other URL is an example of a request to the WMS service (see Chapter 4 to learn how to use API). Page 14 of 38

14 Figure 8: Product info - Description and Data access It is possible to read the product description under the area map, and it is possible to access the product detailed information and metadata by clicking on the title of the product description (it will lead to the EUMETSAT Product Navigator Page, Figure 9). Page 15 of 38

15 Figure 9: Product Navigator page for a selected product Add selected products to the map viewer Once the user choses the product to display from the archive, it is possible to click on the Add to map button and the product will be automatically added to the map viewer. The product image loaded by default is the last ingested image in the system of the selected product (the date/time indicator indicates the time of the image). When a layer is displayed on the map viewer, it is possible to zoom in or out by using the zoom tool or your mouse wheel. It is possible to move the map by dragging it with the mouse (hold down the left button). It is possible to display the images in the entire time archive acting on the Date/time tool (Calendar or arrows) or on the time slider (Figure 10). Page 16 of 38

16 Figure 10: Manage image time It is possible to check the availability in time of the selected product with the time slider, activating the Expand timeline (Figure 11). A thick line will display when the product is available. When the time scale is set to Hours, product availability is displayed by dots. Figure 11: Product availability in time When a product is displayed on the map viewer, its name appears in the list of layers, on the upper left of the page. From this menu it is possible to act on the displayed products and on the map view settings (Figure 12). Figure 12: Loaded products Page 17 of 38

17 For every product, the possible actions are listed in the Table 1. Move the product up and down in the layers pile. Make the product visible or invisible Change product s opacity Open the product s description Remove the product from the map viewer Table 1: Layer functionalities From the map view settings (Figure 13), it is possible to: Select the projection (Geographic, Spherical Mercator, Polar), Switch on and off coastlines and Boundaries. Figure 13: Map view settings Image download options It is possible to download images of the current map using the Download current map view button. This will open the download window (Figure 14). Page 18 of 38

18 Figure 14: Download map modes: Current map view (above), Full resolution product (below) From this dialog box it is possible to: Choose the Mode : o Current map view (it downloads an image of what is displayed on the map viewer in that moment) o Full resolution product (the entire geographical extent for a selected product). Choose the map size in case of download of current map (width and height, with the option to keep the aspect ratio). Choose the format to be downloaded (for WMS products: PNG, JPEG, GeoTIFF, KMZ, for WCS product SST: GeoTIFF, for WFS product: SHP, GeoJSON, GML). Include or not the base layers (in case of download of current map). Add a footer, i.e. the EUMETSAT logo and the information of date and time of the image (in case of download of current map). Once the options are set, just click on Download button to start the download. Page 19 of 38

19 3.3.6 Maps Animation It is possible to create animation based on the currently displayed products. Select the products to be animated and a zoom level, then click on the Setup animation button to open the animation dialog box (Figure 15). From this window it is possible to set the start and the end date and time of the animation, the time step and the animation speed in FPS (Frame per second). Once the settings are defined, a part of the time slider (in expanded mode) in which the animation shall be run is highlighted. Clicking on the Play button starts the animation. The button repeats the animation. The small clock icon Set the driving layer indicates which is the layer whose temporal resolution is driving the animation (for example, if Natural Color RGB is selected as driving layer, the default step for the animation shall be 15 minutes). Figure 15: Maps animation 3.4 Functionalities available ONLY for Registered Users Some of the map viewer functionalities are available only to registered users Getting data values for WCS and WFS products Products Sentinel 3 SLSTR GHRSST Level 3 Uncollated Sea Surface Temperatures (SST) and METOP ASCAT Coastal Winds at 12.5 km Swath Grid Visualisation are provided not only through the WMS service as images, but also as actual data, through the WCS and WFS services respectively. This means that users can query these product when displaying them on the map viewer. To query the product, just click on the displayed product on the map viewer. Values shall be displayed in a pop-up window, with different parameters according to the product (see Figure 16). It is also possible to access to the product legends clicking on the button. Page 20 of 38

20 Figure 16: Getting data values In the case of the SST product, it is also possible to get a time series of the values in a selected point. Just click on the and the time series window shall be open, where it is possible to set the time range to analyse (Figure 17). Figure 17: SST time series Page 21 of 38

21 3.4.2 Download animation Once the animation settings are applied, it is possible to save the animation in mp4 format using the Download configured animation button Downloads status It is possible to access the list of downloads for images or animations with the Downloads status button (Figure 18). Figure 18: Download requests status Save maps It is possible to save the displayed map within the user profile using the Save map view button. The map shall be saved with all the current map settings (displayed layers, projection, opacity, zoom, date and time). Once the map is saved, it is possible to reload it from the My Views section (see following paragraph). When clicking on the Save map button, a dialog box shall open, to allow the user to set the name of the saved map, the Time mode: Event view to show images from a given event at a specific date and time. They shall be displayed in the list of views with this icon. Latest available in order to have always up-to-date maps, i.e. the most recent available images from the selected visualizations, and in this case the view shall be displayed in the list of views with this icon My Views Views are defined as one (or more) products added to a map, displayed in a certain zoom, date/time, transparency and projection. Users can save their Views using the Save map view button. Page 22 of 38

22 From the My Views button it is possible to access to all the saved Views (see Figure 19), to create a new map from scratch or to clone an existing map to work on. The Set View as preferred button allows the user to set the view as preferred (default) one. Figure 19: My Views functionalities For every saved view, different options are available (Table 2): Edit map view: opens the dialog box to edit the view settings (name, time). Clone map view: to create another view with the same settings. Share view: to create a URL that it is possible to share with other users. A dialog box opens with the link to copy and paste. Delete the view. Table 2: View functionalities It is possible to switch between the saved maps loading them on the map viewer by acting on the arrow near the name of the loaded map, or to display them all from My Views and then clicking on the Load button User settings and default landing page User settings box (Figure 20) is accessible from the User section, on the upper right of the page. From this box it is possible to display the user basic information (username, , and license) and from the tab Settings it is possible to choose if using the list of saved Views or to load the View set by default as landing page. Page 23 of 38

23 Figure 20: User profile settings Page 24 of 38

24 4 EUMETSAT WEB MAP SERVICE API EUMETSAT Web Map Service allows dedicated Application Program Interface (API) to be used to build user s own scripts in order to browse products in the archive, access them and download imagery and data in an automated way. In Particular, EUMETSAT Web Map Service can be accessed by sending requests through the OGC standard Web Map Service (WMS). Together with the WMS Service, some products can be accessed also through a WCS (Web Coverage Service) or a WFS (Web Feature Service). The OGC (Open Geospatial Consortium) is an international no-profit organization committed to making quality open standards for the global geospatial community. (More about OGC: OGC services are specifically implemented to exchange geospatial data between different GIS systems and data stores. Those standards are freely available to use for anyone, in order to improve managing processing and sharing of geospatial data. They consist of interfaces that allow the access to imagery, data or functionality on the Web in a standardized way, can run on different platform and frameworks and can be integrated into other applications. These services are implemented to grant the most possible interoperability among different software applications. The benefits in using a OGC service is that it is easier for users to integrate and overlay online data from multiple sources in a seamless way, without having troubles with data format or CRS or data model, thus providing a faster and more efficient way to access data. Besides, it is useful in the case of data which are frequently updated (for example, EUMETSAT near-real-time data such as Meteosat and Metop products). 4.1 Getting a valid access token for licensed images and data In order to access licensed data and visualizations, users need to have an API access token to add to their requests. The access token can be generated using the following workflow: Take your encoded credentials (this information will be provided with username and password). Issue the following call (curl is used as an example, other clients will be equivalent), replacing the placeholder <Base64-encoded-client_key:client_secret> with your encoded credentials: curl -k -d "grant_type=client_credentials" -H "Authorization: Basic <encoded_credentials>" The response of the API manager is a JSON containing the access token: {"access_token":"abcc226a-588d-34e4-919a- 1cd5dbf5ff6f","scope":"am_application_scope default","token_type":"bearer","expires_in":3600} Please, note that the created access token has a limited validity, indicated by the value of expires_in" in the response. Once the token is expired, another one needs to be created to access licensed visualizations and data. Page 25 of 38

25 4.2 OGC Web Map Service (WMS) An OGC Web Map Service (WMS) is a web protocol which provides a simple HTTP interface for requesting online maps through a Uniform Resource Locator (URL). Maps retrieved with a WMS service can be provided as georeferenced images (i.e. with an associated coordinate reference system). Those images can be displayed either on a web browser or loaded as a layer in a GIS desktop software (for example QGIS, but also ArcGIS, MapInfo, AutoCAD, Google Earth or any other software which includes the WMS-client capability). The main benefit of using a WMS service is that the user can access geographic images and use them for maps creation without the need of downloading the data on local disk or local net, thus saving time and local digital space. Maps provided by a WMS service can be usually downloaded in different formats, such as PNG, JPG, GeoTiff, and KML. The current version of the WMS specification is v1.3.0, which is the version supported by EUMETSAT Web Map Service. How it works: A WMS interacts with the server containing the products archive by sending dedicated requests through a series of URL parameters. When the response is received, the WMS sends it back the client in the form of one (or more) georeferenced image(s) that can be displayed in a web browser or in a GIS desktop. A WMS requests from a client can perform different operations (which correspond to different request types). These operations are described in detail in the OGC WMS specification ( ), which defines syntax for URLs to invoke map operations. The most important request from a WMS is the GetCapabilities operation, which provides metadata about the service, including supported operations, parameters, and a list of the available layers that a WMS server can offer. An XML encoding (Extensible Markup Language, a mark-up language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable) is defined for service-level metadata. The full WMS official documentation is available at the link NOTE: in order to access licensed visualisations and data product, users shall need an access token Sending requests to a WMS service In order to interact with EUMETSAT Web Map Service using OGC WMS standard, a client is required (software component that can invoke an operation from a server), which can connect to the service. A generic web browser is the simplest client of a WMS Service. Requests to WMS Service can be issued through HTTP, in particular client applications work with a string created by appending parameters to the service s URL. The request is composed by different parts: the first one is a link to the WMS service, then, using different separators, a certain number of couples parameter/value will follow (the first two are the type of service and the type Page 26 of 38

26 of request). The type of parameters change according to the type of request, and their corresponding values change according to what the user wants. In Figure 21 is illustrated a generic request to a WMS Service: Figure 21: Structure of a generic WMS request To connect to the WMS service, it is needed the service URL (the location of the WMS service), usually known as end point of the service. EUMETSAT Web Map Service WMS Service end point URL is: To download maps from EUMETSAT Web Map Service, it is necessary to send two different requests to the WMS in this order: 1. GetCapabilities request: to retrieve WMS metadata as an xml file. 2. GetMap request: to download the selected map How to send a GetCapabilities request The result from a GetCapabilities request includes the WMS service-level metadata, the description of services and contents, the supported operations and parameters to generate WMS requests and a list of the available layers. Metadata for each layer include different information: bounding box, coordinate reference system, URI of the data, whether the layer is opaque or not etc. In order to send a GetCapabilities request to EUMETSAT Web Map Service, it is necessary to append to the URL the address to the end point URL and the required parameters/values couples. Three parameters (and values) must always to be passed in a GetCapabilities request, as displayed in Table 3. Page 27 of 38

27 Request parameter Value description Values for EUMETSAT Web Map Service Service end point Service to connect to. service version request The service name. It tells the server that a WMS request is forthcoming. It tells the server which version of the WMS is being requested The name of the operation. It tells the server that the operation requested is the GetCapabilities operation. WMS GetCapabilities access_token The access token required to access licensed data Valid token Table 3: Parameters and values of a GetCapabilities request Following the request structure of the previous figure, here is how to send the request: est=getcapabilities&version=1.3.0&access_token=your_token_here Opening the above link in a web browser returns the WMS service metadata as an XML document. This document is a detailed description of the WMS service. It contains three main sections: Service Capability/Request Capability/Layer Service metadata (i.e. the service name, the keywords, contact information etc.). Describes the operations the WMS service provides and the parameters and output formats for each operation. List of the available products. For each layer service metadata (such as title, abstract, bounding box, time etc) are provided. Table 4: Sections of a GetCapabilities xml response It is possible to search the name of the layer to download in the metadata file among the <Name> tags of the document (for example RGB Natural Color can be found as <Name>MSG15_HRSEVIRI_RGB_NATCOLOR_GEOTIFF</Name>). In the sub-elements nested in the <Name> element, it is possible to find all the metadata related to the product, included the available date/times (in the format: start date/end date/step) in which it is possible to display the product (Figure 22). Page 28 of 38

28 Figure 22: Example of a GetCapabilities response xml file A GetCapability URL request for each single product can be found in the Data Access tab in the Product Detail page of a specified product How to send a GetMap request Once a product of the archive has been selected together with the date/time to display and an area of interest, in order to be able download the map, a GetMap request must be sent. A WMS server responding to a GetMap request returns a map imagery for the specified area and content. The request has a similar structure as the GetCapabilities request, but it is necessary to specify further parameters/value couples. For example, in order to download an MSG RGB Airmass (product name is MSG15_HRSEVIRI_RGB_AIRMASS_GEOTIFF) imagery in the full disk area, it is necessary to append to the request the following parameters/values (separated by the & symbol), as listed in Table 5. It is possible to add also other parameters to the request, please refer to the OpenGIS Web Map Service (WMS) Implementation Specification for the complete list. Page 29 of 38

29 Request parameter Value description Value for GetMap request Service end point Service to connect to. umetsat/ows? service The service name. WMS version EUMETSAT WMS version layers The layer name MSG15_HRSEVIRI_RGB_AIRMA SS_GEOTIFF width, height format bbox srs time access_token Width and height in pixels of the downloaded image The format of the downloaded image (in this case a jpeg file shall be downloaded) Coordinates of bounding box corners (lower left, upper right). Important note: for SRS values which are geographic coordinate systems (in this case WGS84), the bbox parameters are must be in the format latitude/longitude, or y/x. The Coordinate reference system (in this case is WGS84) The date/time of the image. For example April, at 15:30 UTC. The access token required to access licensed data Table 5: Parameters and values of a GetMap request 800,800 jpeg -77,-77,77,77 EPSG: T15:30:00.000Z Valid token The resulting URL string to request the full disk Airmass imagery in date 21/04/2018 at 15:30, in jpeg format and in an image of size 800x800 is the following: ht=800&bbox=-77,-77,77,77&layers=eumetsat:msg15_hrseviri_rgb_airmass_g EOTIFF&crs=EPSG:4326&service=WMS&request=GetMap&width=800&version=1.3. 0&time= T15:30:00.000Z&access_token=your_token_here When the URL is open in a web browser, the response to the request is displayed in Figure 23: Page 30 of 38

30 Figure 23: Resulting image from the GetMap request It is possible to change the parameters to request different images. For example: Adding more than one product (in this case RGB MPE and SEVIRI IR 3.9) to the map. Layers must be added separated by a comma: e/jpeg&height=800&bbox=-77,- 77,77,77&layers=MSG15_HRSEVIRI_IR_39_GEOTIFF,MSG15_HRSEVIRI _RGB_MPE_GEOTIFF&crs=EPSG:4326&service=WMS &request=getmap&width=800&version=1.3.0&time= T10:30:00.000Z&access_token=your_token_here Changing the image format (in this case georeferenced GEOTiff) e/geotiff&height=800&bbox=-77,- 77,77,77&layers=eumetsat:MSG15_HRSEVIRI_RGB_AIRMASS_GEOTIFF &crs=epsg:4326&service=wms&request=getmap&width=800&version =1.3.0&time= T10:30:00.000Z&access_token=your_token_here Select a bounding box (in this case a zone on Europe and North Africa). Coordinates must be in the order lower left corner and upper right corner. Remember to use the format latitude/longitude, or y/x in case of SRS which are geographic coordinate systems (here WGS84). This is an example applied to RGB Natural Colour. e/jpeg&height=600&bbox=30,- 13,65,40&layers=eumetsat:MSG15_HRSEVIRI_RGB_NATCOLOR_GEOTIF F&crs=EPSG%3A4326&service=WMS&access_token=f4afa10f-4f86-38cc-aa04- Page 31 of 38

31 12e60e8865f5&request=GetMap&width=800&version=1.3.0&time= T15:30:00.000Z&access_token=your_token_here 4.3 OGC Web Feature Service (WFS) and Web Coverage Service (WCS) While a WMS returns an imagery (portrayal) of the selected product(s), OGC Web Feature Service (WFS) and Web Coverage Service (WCS) web protocols define the interfaces and the operations to access actual data (they return respectively the values of the actual selected feature or pixel, not only an imagery), analysis and processing a set of geographic features or coverages from an underlying data repository. Allowed operations for a WFS are: GetCapability (Generates a metadata document describing a WFS service provided by server as well as valid WFS operations and parameters), DescribeFeatureType (description of any feature types supported by the WFS), GetFeature (retrieval of a selection of features (geometry and attribute values) from the data source). Allowed operations for a WCS are: GetCapability (Retrieves a list of the server s data, as well as valid WCS operations and parameters), DescribeCoverage (XML document containing a full description of the coverages within thewcs, like spatial extent, spatial resolution, cell size, spatial reference system etc.), GetCoverage (retrieval of the requested coverage in a known format). It is possible to find all the information and the document for both the services at the following links: Web Coverage Service (WCS) Web Feature Service (WFS) Besides, in the following links the references for both the services: In the case of EUMETSAT Web Map Service, there is a product that can be accessed using the WFS, which is the METOP ASCAT Coastal Winds at 12.5 km Swath Grid Visualisation, and a product that can be accessed through the WCS, which is the Sentinel 3 SLSTR GHRSST Level 3 Uncollated Sea Surface Temperatures (SST). Please, note that these products can be accessed also as imagery through a WMS GetMap request. Page 32 of 38

32 4.3.1 WCS or WFS GetCapabilities request The file returned from a GetCapabilities request includes the WFS or WCS service-level metadata, and the description of the supported operations and parameters to generate requests, a list of the available formats and EPSG. As in the case of WMS, in order to send a GetCapabilities request it is necessary to append to the URL of the endpoint three parameters/values couples. Three parameters (and values) must always to be passed in a GetCapabilities request, as displayed in Table 6. Request parameter service end point service version product request access_token Value description The service name. It tells the server which version of the service is being requested. Name of product to query. The name of the operation. It tells the server that the operation requested is the GetCapabilities operation. The access token required to access licensed data. Values for WCS Values for WFS WCS WFS sst_orbits_composition GetCapabilities Valid token Table 6: Parameters and values of a GetCapabilities request metopa_ascat Following the request structure of the previous table, here is how to send the two requests: WCS GetCapabilities sst_orbits_composition/ows?service=wcs&request=getcapabilities&v ersion=2.0.1&access_token=your_token_here WFS GetCapabilities vice=wfs&request=getcapabilities&version=2.0.0&access_token=your _token_here Page 33 of 38

33 4.3.2 WFS DescribeFeatureType The scope of a DescribeFeatureType request is to generate a schema description for the selected feature types in order to have information about the selected product before requesting the actual data (GetFeature request). The resulting document is a list of features and the related attributes. Parameters (and values) to be passed in this kind request are displayed in Table 7. Request parameter Value description Value for GetMap request service end point umetsat/ows? service The service name. WFS request The name of the operation. DescribeFeatureType typenames Name of the feature type to describe eumetsat:metopa_ascat version Which version of the service is being requested format The format of the response document text/xml; subtype=gml/3.1.1 access_token The access token required to access licensed data Table 7: Parameters and values of a DescribeFeatureType request Valid token Following the request structure of the previous table, here is how to send the request: t/xml;+subtype=gml/3.1.1&service=wfs&request=describefeaturetype &typenames=eumetsat%3ametopa_ascat&version=2.0.0&access_token=yo ur_token_here WFS GetFeature The scope of a GetFeature request is to return a selection of features from the selected data source (in this case METOP ASCAT). Parameters (and values) to be passed in this kind request are displayed in Table 8. Page 34 of 38

34 Request parameter Value description Value for GetMap request Service end point umetsat/ows? service The service name. WFS request The name of the operation. GetFeature typename Name of the feature type to describe eumetsat:metopa_ascat version Which version of the service is being requested time YYYY-MM-DDThh:mm:ss.sssZ T03:48:00Z bbox srsname outputformat access_token Coordinates of bounding box corners x min, y min, x max, y max The Coordinate reference system (in this case is WGS84) The format of the downloaded file. Different options available (gml, shp, kml etc) The access token required to access licensed data Table 8: Parameters and values of a GetFeature request 64,-23,91,3 EPSG:4326 text/xml; subtype=gml/3.1.1 SHAPE-ZIP KML json Valid token Following the request structure of the previous table, here are examples how to send the request: Request a KML in the area included in the polygon 64,-23,91,3 (lon/lat values) and at the time :48: ,91,3&srsName=EPSG:4326&outputFormat=KML&service=WFS&request=G etfeature&typename=eumetsat:metopa_ascat&version=2.0.0&time= t03:48:00z&access_token=your_token_here Request a shapefile in the same area/time as above 23,91,3&srsName=EPSG:4326&outputFormat=SHAPE- ZIP&service=WFS&request=GetFeature&TYPENAME=eumetsat:metopa_asca t&version=2.0.0&time= T03:48:00Z&access_token=your_token_here How to get the list of available times for WFS You can send a GetPropertyValue request, using as typename the value metopa_histogram and as valuereference time. ion=2.0.0&request=getpropertyvalue&typename=metopa_histogram&val uereference=time Page 35 of 38

35 4.3.4 WCS DescribeCoverage This operation send a request to get a full description of a selected product (in this case SST). The server replies with a document in XML format fully describing the requested Coverages. The XML document provides information about projections, time range, bounding box etc, which are useful to know before requesting the actual data (GetCoverage request) Parameters (and values) to be passed in this kind request are displayed in Table 9. Request parameter Value description Value for GetMap request service end point umetsat/ows? service The service name. WCS request The name of the operation. DescribeCoverage coverageid Name of the feature type to describe eumetsat:sst_orbits_composition version access_token Which version of the service is being requested. The access token required to access licensed data Table 9: Parameters and values of a DescribeCoverage request Valid token Following the request structure of the previous table, here is how to send the request: est=describecoverage&version=2.0.1&coverageid=eumetsat:sst_orbit s_composition&access_token=your_token_here WCS GetCoverage This operation send a request to download actual spatial data from a selected product (in this case SST). The request returns a coverage in different formats (NetCDF, GeoTIFF etc). Requests can be subset according to different parameters (area, time etc). Parameters (and values) to be passed in this kind request are displayed in Table 10. Page 36 of 38

36 Request parameter Value description Value for GetMap request Service end point umetsat/ows? service The service name. WCS request The name of the operation. GetCoverage coverageid Name of the feature type to describe eumetsat:sst_orbits_composition version format subset (time) Which version of the service is being requested. Format of the downloaded file (different options available). The time selected (values taken from the DescribeCoverage document) NetCDF GeoTIFF subset=time("yyyy-mm- DDThh:mm:ss.sssZ") subset (bbox) The area of interest subset=long(-x min, x max)&subset=lat(y min, y max) access_token The access token required to access licensed data Table 10: Parameters and values of a GetCoverage request Valid token Following the request structure of the previous table, here are examples how to send the request: Request a GeoTIFF in the area Long(62,75)/Lat(0,5) and at the time T04:26:34.000Z: (" T04:26:34.000Z")&subset=Long(62,75)&subset=Lat(0,5)&versi on=2.0.1&service=wcs&coverageid=sst_orbits_composition&form at=image/geotiff&request=getcoverage&access_token=your_toke n_here Request a NetCDF in the area Long(35,125)/Lat(-35,20) and in the time range 15/02/ :14:24 and 15/02/ :48:40 (" T02:14:24.000Z"," T03:48:40.000Z")&subset=Long(35,125)&subset=Lat(- 35,20)&version=2.0.1&service=WCS&coverageId=sst_orbits_comp osition&format=application/xnetcdf&request=getcoverage&access_token=your_token_here How to get the list of times from WCS Service est=describedomains&layer=sst_orbits_composition&tilematrix=epsg :4326&Domains=time&ExpandLimit=10000 Page 37 of 38

37 5 KNOWN ISSUES FOR EUMETSAT WEB MAP SERVICE GUI In this paragraph we are going to list the already known issues about EUMETSAT Web Map Service. Please take note of these issues, while we are working on the improvement of the service in order to give our users a better experience. Known issues Please, consider to use Chrome for testing the The size of the archive of visualizations is limited for the User consultation period to about 2-3 months of data. The EUMETSAT Web Map Service environment is not operational so some time slots data and NRT data might be missing from the available archive. Tile and Tree tooltips are obscured by the menu window when displaying the list of products. Time series functionality for Sentinel-3 SST product is not working. Issues with products: MPE: at lower levels of zoom it is possible to display only MPE high values. To display all the values you have to zoom in. Airmass: some pixels that are supposed to be black are displayed as transparent. Page 38 of 38