Proposed update of Technical Guidance for INSPIRE Download services based on SOS Matthes Rieke, Dr. Albert Remke (m.rieke, 52°North GmbH Workshop - INSPIRE Download service based on SOS 8 th April 2014, Joint Research Centre – European Commission

2 Current State of the TG 4 INSPIRE Download Services 4.1How the Technical Guidance maps to the Implementing Rules 4.2Conformance Classes for Download Services Technical Guidance 4.3Language Requirements 4.4Implementation Roadmap for Download Services 5Atom Implementation of Pre-defined Dataset Download Service 6Web Feature Service and Filter Encoding Implementation of Pre-defined Dataset Download Service 7Web Feature Service and Filter Encoding implementation of Direct Access Download Service 8Quality of Service

3 4 INSPIRE Download Services 4.1How the Technical Guidance maps to the Implementing Rules 4.1.4Mapping the SOS-based Technical Guidance to the Implementing Rules 4.2Conformance Classes for Download Services Technical Guidance 4.3Language Requirements 4.4Implementation Roadmap for Download Services 5Atom Implementation of Pre-defined Dataset Download Service 6Web Feature Service and Filter Encoding Implementation of Pre-defined Dataset Download Service 7Web Feature Service and Filter Encoding implementation of Direct Access Download Service 8Sensor Observation Service and Filter Encoding implementation of Pre-defined Dataset Download Service 9Sensor Observation Service and Filter Encoding implementation of Direct Access Download Service 10Quality of Service Proposal Change Overview

4 Digression – SOS Conformance Classes SOS Core –GetCapabilities, DescribeSensor, GetObservation Spatial Filtering Profile –Observations are restricted to spatial observations –Spatial filters allow targeting of the sampling geometries XML Encoding –Encoding definitions for all interface operations Core KVP Binding –Invocation of SOS operations over HTTP GET with Key-Value-Pair encoding –GetCapabilities, DescribeSensor, GetObservation ISO –Query “… performs a search over some set of resources and returns a subset of those resources.” –Minimum Spatial Filter Bounding box spatial operator –Minimum Temporal Filter During temporal operator

5 Download Services Mapping Implementing Rules – SOS Conformance Classes –Get Download Service Metadata SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding –Get Spatial Data Set SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding, ISO 19143: Query –Describe Spatial Data Set SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding –Get Spatial Object SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding –Describe Spatial Object Type SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding –Search Criteria for the Get Spatial Object Operation SOS Core, Spatial Filtering Profile, XML Encoding, Core KVP Binding, ISO 19143: Minimum Spatial Filter, Minimum Temporal Filter

6 Pre-defined Dataset Download Service – Requirements TG Requirement 70: Implementations of an SOS pre- defined dataset download service shall conform to the [OGC SOS] Conformance Class ‘SOS Core’ TG Requirement 71: The Conformance Class ‘Spatial Filtering Profile’ as defined by [OGC SOS] shall be enabled to ensure that each observation served through the download service provides a sampling geometry. –INSPIRE Directive requirement for reference to a specific location or geographical area TG Requirement 72: Implementations of an SOS pre- defined dataset download service shall conform to the [OGC SOS] Conformance Classes ‘Core KVP Binding‘ and ‘XML Encoding’.

7 Pre-defined Dataset Download Service – Requirements TG Requirement 73: A spatial dataset shall be made available through a separate SOS offering and be retrievable through a GetObservation query. –Reminder: Spatial dataset = Observation offering

8 Pre-defined Dataset Download Service – Requirements Provision of INSPIRE Metadata elements is a requirement –Extend the SOS GetCapabilities response (extended capabilities section) Two options –Metadata by reference ( ) –Metadata inline TG Requirement 74: INSPIRE Metadata for the Download Service shall EITHER be linked to via an in an extended capabilities section, OR the extended capabilities section shall contain all the INSPIRE Metadata for the Download Service in accordance with the inspire_dls:ExtendedCapabilities schema.

9 Pre-defined Dataset Download Service – Requirements Multilingualism, CRS and INSPIRE namespaces –Mandatory: GetCapabilities –Service metadata –Observation offerings Default and Supported must be defined –Language –CRS INSPIRE Namespace via / TG Requirement 75: For each data set, the information about supported languages, namespaces and CRS shall be provided in the corresponding ObservationOffering section in the SOS Capabilities document. TG Requirement 77: A client may specify a specific CRS in a GetObservation request. If the requested CRS is contained in the list of supported CRS, the coordinates returned in the service response shall be in the requested CRS. If the requested CRS is not supported by the service, then a corresponding exception shall be returned. TG Requirement 78: A network service [Download Service] metadata response shall contain a list of the natural languages supported by the service. This list shall contain one or more languages that are supported. TG Requirement 79: A client may specify a specific language in a request. If the requested language is contained in the list of supported languages, the natural language fields of the service response shall be in the requested language. If the requested language is not supported by the service, then this parameter shall be ignored.

10 Pre-defined Dataset Download Service – Requirements Language support realization for GetCapabilities –Additional parameter for Core KVP Binding TG Requirement 80: The name of this parameter shall be “LANGUAGE”. The parameter values are based on ISO 639-2/B alpha 3 codes as used in [INS MDTG]. Example: Capabilities&SERVICE=[...]&VERSION=[...]&LANGUAGE=eng

11 Pre-defined Dataset Download Service – Recommendations Language Recommendations –Although further multilingual support is not required for INSPIRE Network Services, it may be desired by a service provider to implement further multilingual support such as: multilingual error messages multilingual support for additional Operations including HTTP/POST- and HTTP/GET-Binding Operations: GetObservation, GetObservationById, GetFeatureOfInterest, DescribeSensor

12 Pre-defined Dataset Download Service – Recommendations CRS Recommendations –TG Recommendation 22: If the CRS parameter is absent in the request, ETRS89 should be used as a default CRS. –TG Recommendation 23: If a SOS server implements the optional GetFeatureOfInterest operation, the CRS handling should be implemented as it has been specified for the GetObservation operation.

13 Direct Access Download Service – Requirements Add-on to Pre-defined Dataset Download Service –follow all requirements Allow sub-setting of resulting observations Query parameters –Minimum Spatial Filter (bounding box) is covered by the GetObservation operation in conjunction with the spatial filtering profile –Filtering for the relevant key attributes Observed property Feature of interest Procedure –Temporal filters are covered by default through the SOS interface (Minimum Temporal Filter including “during a time period” and “equals to a time instant”). –Querying by identifier of spatial object GetObservationByID

14 Direct Access Download Service – Requirements INS NS requires the spatial data theme as a query parameter –when a user connects to a SOS, this user already queries one specific spatial object type (defined in one spatial data theme) –in case of the SOS this query parameter might not be useful  Discussion and approach required

15 Hybrid Download Services Implementations Combinations of SOS with WFS and/or Atom –Extend and reuse existing infrastructure –Provide features via WFS instances TG Recommendation 19: Implementations of SOS servers to be used as INSPIRE Download Service should support the GetFeatureOfInterest operation as defined by the SOS standard to provide access to the geometries to which the offered measurements are associated to. TG Recommendation 20: Implementations of SOS servers to be used as INSPIRE Download Service may refer to a WFS server for providing the features to which the offered measurements are associated to. In this case the feature elements returned in a SOS response should consist of URIs through which the features can be downloaded from a WFS. TG Recommendation 26: In addition, a textual reference to the Atom service implementing part A should be included in the ‘abstract’ metadata element of the SOS. TG Recommendation 27: In addition, a textual reference to the WFS service providing the features of interest should be included in the ‘abstract’ metadata element of the SOS.