of several types (e.g. OGC Services, KML data, etc.) to be discovered ... of search engines is that they are crawling the web to discover information resources ...
Geocatalogue of Geospatial Information Provided by OGC Services Discovered on Google Tomas Kliment1, Carlos Granell2 , Vlado Cetl2, and Marcel Kliment3 1
Slovak University of Technology, Faculty of Civil Engineering, Dept. of Theoretical Geodesy, Bratislava, Slovakia
2 Joint 3
Research Centre , Institute for Environment and Sustainability, Digital Earth & Reference Data Unit, Ispra, Italy
Slovak University of Agriculture, Horticulture and Landscape Engineering Faculty, Dept. of Landscape Planning and Ground Design, Nitra, Slovakia
INTRODUCTION
FINAL PRODUCT AND FUTURE WORK METHODOLOGY – WORKFLOW OVERVIEW
Nowadays many ways exist to search and retrieve geospatial information (GI) on the web. Very well know and mostly used systems for spatial browsing such as Google Maps provide an easy and user friendly way to discover daily used GI as for instance addresses, points of interest and routes between POI, etc. On the other hand an Spatial Data Infrastructure (SDI) provides more detailed information (on protected sites, natural hazard risk zones, energy resources, geology, etc.) with advanced level of searching possibilities based on their documentation through metadata. However, data providers need to create and publish metadata in a predefined structure describing their GI resources in order to make them discoverable through an SDI. This fact may decrease the amount of GI resources available through current geoportals on a global (e.g. GEO Portal ), Regional (INSPIRE Geoportal ) or National levels (Geoportal SR). Furthermore, as current research activities have reported, so called mainstream web provide many valuable GI resources of several types (e.g. OGC Services, KML data, etc.) to be discovered using internet search engines such as Google, Yahoo or Bing. The benefit of search engines is that they are crawling the web to discover information resources automatically. Therefore no additional work is required, besides to publish URL addresses of available resources on a web page or portal.
• Geocatalogue of Geospatial Information provided by OGC services discovered on Google • Discovery client, metadata details and map web view client • OGC Catalogue Service for Web endpoints for each OGC service (WMS, WFS, SOS …) and the GI representation it provides (WMS Layers, WFS Features, SOS Observations …) • To be extended and sophisticated the crawling functionality • Automatic periodical searching for the OGC services • Extend the searching area (other SE, social networks, etc.) • Searching for other operations supporting GET binding • Qualitative monitoring of the OGC services
• Detailed analyses of relationship mainstream vs. SDI concerning the existence of GI resources available on the mainstream within the SDI implementations
The poster describes the Geocatalogue of geospatial information provided by OGC services discovered on Google, which has been implemented as a result of a methodology proposed to discover OGC services on the mainstream search engine Google. The GetCapabilities URL addresses were searched for 7 types (WMS, WFS, WCS, WPS, SOS, WMTS and CSW) of OGC services 5 times using Web Search Client of Google SE. The URL addresses of discovered OGC services were stored in database and verified to define their availability and retrieve the service version. Metadata harvesting tasks were created and run for functioning services in GeoNetwork opensource in order to collect metadata for both OGC services and the representation of the GI resources they provide (WMS Layers, WFS Features, WCS Coverages and SOS Observations).
STEP 1: SEARCH FOR OGC GETCAPABILITIES URLS ON GOOGLE SE
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