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3. DISCOVERY PROCESSES,
SEARCHING FOR SPATIAL DATA AND
WEB SERVICES
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• The main ingredients we need to discover relevant
spatial data/data series/services/… are:
– 1. Metadata describing a resource
(in exchangeable format)
– 2. Discovery service
The concept of discovery in ESDI
1. 2.
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Designation of the same is different in
OGC services and INSPIRE
• Get used to it!
• Do you know OGC (Open Geospatial Consortium) Catalogue
Service for Web?
– Then you know INSPIRE Discovery service
• Do you know OGC (Open Geospatial Consortium) Web Map
Service?
– Then you know INSPIRE View service
• Do you know OGC (Open Geospatial Consortium) Web
Feature Service?
– Then you know INSPIRE download service
• To be continued…
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1. Through a “thin” client
– typically a Web browser
2. Through a “thick” client
– e.g. a catalogue client, common for GI professionals
Two possibilities of connecting to a
discovery service
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• Type in http://inspiregeoportal.ec.europa.eu/discovery/
or
http://geoportal.gov.cz/web/guest/catalogue-client
Let’s make it simple…a use case with
Web browser
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• Sure, all this is originating from INSPIRE legislation
• COMMISSION REGULATION (EC) No 976/2009 of 19
October 2009 implementing Directive 2007/2/EC of the
European Parliament and of the Council as regards
the Network Services
• http://inspire.ec.europa.eu/index.cfm/pageid/5
Legislation background
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• Sure, all this is originating from INSPIRE legislation
Legislation background
Aren’t you missing anything?
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Intersect as a spatial operator
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• Get Discovery Service Metadata
– i.e. GetCapabilities according to the OGC
• Discover Metadata
– i.e. GetRecords according to the OGC
• Publish metadata
– i.e. harvest, transaction according to the OGC
• Link Discovery service
– an equivalent of service chaining according to the
OGC
Operations of an INSPIRE discovery service
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• Intended for “thick” clients
• Not applicable for an ordinary user with a
Web browser
Get Discovery Service Metadata
catalogue client
http://geoportal.gov.cz/php/micka/csw/index.php?
SERVICE=CSW&REQUEST=GetCapabilities
Title Czech Republic INSPIRE metadata catalogue
Service type INSPIRE Discovery Service (CSW – Catalogue Service for Web according to the
OGC)
Service version 2.0.2
Supported languages Czech, English
Fees Free of charge
Responsible Party CENIA, Czech Environmental Information Agency
E-mail info@cenia.cz
Supported operations Get Discovery Service Metadata
Discover Metadata
Publish metadata
Link Discovery service
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Discover Metadata
1. Choose a resource type
2. Select search criteria as defined by legislation
3. Start searching
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Discover Metadata
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Discover Metadata
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Preview of discovered Web service
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Where is the difference in comparison to
other catalogues?
• It is an SDI catalogue! Enables to search in other
associated catalogues as well at the same time.
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Catalogue server
Client application
Catalogue server Catalogue server Catalogue server
Catalogue server Catalogue server
Chaining of catalogues (through Link
Discovery Service Operation)
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ID: 3d8-4900
revision: 2014-08-20ID: 9a4e
Revision: 2014-08-20ID: 1e400a010817
Revision: 2014-08-20ID: 518b64b1
Revision: 2014-08-20
Publish metadata (harvest)
catalogue
catalogue
1. I would like to update your catalogue
- my authorization details
- list of metadata records including IDs
and the date of the last revision
1. 2.
Note: publish metadata, in this version
designated as harvesting (harvest records)
may be set up periodically.
2. OK, three of four of your metadata
records are new, I am updating them
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Publish metadata (transaction)
catalogue client
1. I would like to update the metadata
record with ID 1e400a010817
- authorization details
2. OK, authorization details are correct,
here is the metadata record with ID
1e400a010817
3. Uploading the modified metadata
record with ID 1e400a010817
1.
2.
3.
Resource Title National parks in the Czech Republic
Identifier 1e400a010817
Abstract A database containing detailed
information about all 3 national
parks in the Czech Republic. This
database…
Classification Environment
Keyword Protected Sites
Date of creation 1995-01-05
Date of revision 1999-04-23
Linkage http://inmapy.cz/data/NatPark
Responsible Party INmapy.cz company
E-mail info@inmapy.cz
2014-08-21
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_v2.0
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• Again defined in legislation
• The response time for sending the initial response to a
Discovery service request shall be maximum 3
seconds in normal situation. Normal situation
represents periods out of peak load. It is set at 90 % of
the time.
• The minimum number of served simultaneous
requests to a discovery service according to the
performance quality of service shall be 30 per
second.
• The probability of a Network Service to be available
shall be 99 % of the time.
Quality of service
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Quality of service
Uptime [%] Maximum downtime
Per week Per month Per year
95 8.4 hours 36.00 hours 18.25 days
98 3.4 hours 14.40 hours 7.30 days
99 1.7 hours 7.27 hours 3.63 days
99.9 10 minutes 0.73 hours 8.76 hours