Global Drought Monitoring Service through the GEOSS Architecture ...

More documents

Recommendations

Info

Architectural Implementation Pilot, Phase 3 Version: 2.0 Global Drought Monitoring and European Drought Observatory-Water SBA Engineering Report Date: 11/Feb/2011 5.1.6 Context and pre-conditions Some of the existing Global Earth Observation System of System functionality has been described above. This section will provide further documentation of EuroGEOSS in providing components supporting advanced search and discovery. The following datasets and services are assumed to be available before the scenario begins: • GEO Portal, through this portal the end user will be able to search, find and access the services which are needed for the Scenario execution; • EuroGEOSS/GENESIS Client Application is registered on the Components and Services Registry (CSR) and accessible through the GEO Portal; • EuroGEOSS Discovery Augmentation Component (DAC) Service. This service federates both semantics (e.g. SKOS repositories) and ISO-compliant geospatial catalog services. The DAC can be queried using common geospatial constraints (i.e. what, where, when, etc.). The service exposes a semantics-extended OpenSearch interface. • EuroGEOSS Discovery Broker Service. This is a distributed catalogue which federates several services (exposing them through the CSW-ISO interface). Federated services publish the following datasets: o Environmental datasets (WCS); o Climate Change datasets (WCS); • GENESIS Vocabulary Service. This repository publishes a SPARQL interface for navigating the aforementioned SKOS-based thesauri. • WPS Client. This is web client for configuring and running data retrieval for graph construction through the European Drought Observatory • GEOSS Ontology Registry • GEOSS Geographic Gazetteer • Application (WPS): the search interface is designed to be accessible through the European Drought Observatory (EDO) portal interface • A workflow engine. This component manages all phases of the scenario (browse semantic repository, retrieve concepts of interest, search for resources related to such concepts, execute WPS) 5.2 Implementation of the European Regional Drought Semantic-enhanced Monitoring and Information System The Drought Scenario that has been used for AIP-3 was originally introduced within presentations of Barbara Hofer and Stefan Niemeyer (European Drought Observatory), “EuroGEOSS for Drought--Linking the EDO to Local and Global Scales,” at the INSPIRE conference in June 2010 and “Drought Data, Metadata, and Interoperability,” at the Training Workshop on Drought Risk Assessment for the Agricultural Sector in September 2010. These Page 52
Architectural Implementation Pilot, Phase 3 Version: 2.0 Global Drought Monitoring and European Drought Observatory-Water SBA Engineering Report Date: 11/Feb/2011 identical drought scenarios are also given within Report D.2.1.1 Report on Requirements for Interdisciplinary Interoperability (L. Vacarri, S. Nativi, and M. Santoro), 2 Nov 2010. The actual scenario which was used is presented in Table 1 below. This scenario is pretty abstract, and the reader may find viewing this scenario more useful by accompanying the reading with a viewing of the video “Drought—European.” 41 along with reading this scenario. The video is actually a “walkthrough,” showing step-by-step how a user interested in drought will use the drought information system, showing the implementation of the scenario. The scenario itself in Table 1 is actually the user requirements before construction of the system, while the video displays the components that have been assembled and implemented to meet these requirements. The use cases Semantics Enabled Search and Ontology Engine Search have been developed in conjunction with the Semantics WG; further details are contained in the EuroGEOSS Broker documentation and the Semantics Working Group Report. Table 3 European Drought Observatory Scenario European Drought Observatory Scenario Step 01: Obtain Drought Indices from European Drought Observatory Step 01.1: Obtain Drought Indices through Standard Services Step 02: A dedicated WPS processes the drought index and calculates the drought hazard Step 02.1: The WPS retrieves the Drought Index through the WCS Step 02.2: The WPS executes the hazard detection model and, where detected, sends an alert to the decision support tool Step 03: Drought Hazard Related Information Discovery Step 03.1: The decision maker uses the decision support tool to submit a query to the augmented search component in order to discover drought hazard related information (datasets) Use Case: Semantics Enabled Search Step 03.1.1: The augmented search component submits a query to the ontology query engine and extracts 0,…N terms to be inserted into the geospatial query Specialized Use Case: Ontology Enabled Search Step 03.1.2: The augmented search component generates one or more geospatial queries based on the user selection as geospatial constraints and/or as keywords from the previous step and 41 http://www.ogcnetwork.net/pub/ogcnetwork/GEOSS/AIP3/pages/Demo.html Page 53
Page 1 and 2: Global Drought Monitoring Service t
Page 3 and 4: Architectural Implementation Pilot,
Page 51: Architectural Implementation Pilot,

Global Drought Monitoring Service through the GEOSS Architecture ...

Create successful ePaper yourself

Delete template?

Save as template?