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Abstract

The ConnectinGEO Observation Inventory (OI) is created and populated using the current information in the metadata concentrated in the GEO Discovery and Access Broker (DAB) of the GEOSS Common Infrastructure (GCI) to analyse the observations and measurements currently available in it. WP4 defined a high-level process for the population of the Observation Inventory: (i) retrieve the full metadata content for each record in the GEO DAB, (ii) extract/Infer extra semantics (connecting to external knowledge systems when needed), and (iii) generate enriched metadata and write it to the OI. The OI system architecture was designed and developed. The first version of the OI was created and populated using the current information in the metadata concentrated in the GEO DAB. The first population process was run in December 2015, resulting in a total of more than 1.6M harvested metadata records. The developed OI is accessible online and can be used as a data source by different analysis tools, which create plots, reports, or summary statistics useful for the ConnectinGEO gap analysis. A simple Web Client was developed to demonstrate how to interrogate the OI and provide also basic examples of how the developed OI can be used by web-based analysis tools. The developed framework is ready to be extended and complements current information with data extracted from additional external sources (URR 2.0, scientific literature DBs, etc.) and the results of ConnectinGEO Task 2.3.
EU Framework Program for Research and Innovation
(SC5-18a-2014 - H2020)
ProjectNr:641538
CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsitu
tofilltheGapsinEuropeanObservations
Deliverable D4.2
Observation inventory description and results report
Version 1
Due date of deliverable: 31/12/2015
Actual submission date: 12/02/2016
Document control page
Title D4.2 Observation inventory description and results report
Creator CNR
Editors CNR
Description Report on the observation inventory description (process,
architecture and APIs) and results report.
Publisher ConnectinGEO Consortium
Contributors ConnectinGEO Partners
Type Text
Format MS-Word
Language EN-GB
Creation date 15/01/2016
Version number 1
Version date 25/01/2016i
Last modified by
Rights Copyright
©
2015, ConnectinGEO Consortium
Dissemination
level CO (confidential, only for members of the consortium)
X PU (public)
PP (restricted to other programme participants)
RE (restricted to a group specified by the consortium)
When restricted, access granted to:
Nature X R (report)
P (prototype)
D (demonstrator)
O (other)
Review status Draft Where applicable:
X WP leader accepted Accepted by the PTB
PMB quality
controlled Accepted by the PTB as public
document
X Coordinator accepted
Action requested to be revised by all ConnectinGEO partners
for approval of the WP leader
for approval of the PMB
for approval of the Project Coordinator
for approval of the PTB
Requested
deadline
Revision history
Version Date Modified by Comments
0.1 29/01/2016 CNR_MS,
CNR_SN First draft.
0.5 10/02/2016 CREAF_JM
52N_SJ Comments/contributions to the draft
1.0 12/02/2016 CNR_MS,
CNR_SN Final version integrating partners’ comments
and contributions.
Contributors
Acronym Full name
CNR_MS Mattia Santoro (CNR)
CNR_SN Stefano Nativi (CNR)
CREAF_JM Joan Maso (CREAF)
52N_SJ Simon Jirka (52N)
Copyright © 2016, ConnectinGEO Consortium
The ConnectinGEO Consortium grants third parties the right to use and distribute all or parts of this
document, provided that the ConnectinGEO project and the document are properly referenced.
THIS DOCUMENT IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENT, EVEN
IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsitutofilltheGapsinEuropean
Observations
Theme:SC5‐1 8a‐2014.Coordin atingEuropean Observation Networksto reinforce the knowledge base forclimate ,natural resources
andrawmaterials
Table of Contents
Executive Summary ......................................................................................................................................... 6
1Introduction .............................................................................................................................................. 7
1.1Scope & purpose of the document .................................................................................................... 7
2Observation Inventory Population ......................................................................................................... 8
2.1Getting Full Metadata Content .......................................................................................................... 8
2.2Extract/Infer Extra Semantics ........................................................................................................... 9
2.3Generate Enriched Metadata Content ............................................................................................ 10
3Observation Inventory Architecture .................................................................................................... 11
3.1ConnectinGEO Analyzer ................................................................................................................. 12
3.2Enricher Types ................................................................................................................................ 12
3.2.1Web Resource Enricher .............................................................................................................. 13
3.2.2Accessibility Enricher .................................................................................................................. 13
3.2.3Record Type Enricher ................................................................................................................. 14
3.2.4Data Enricher .............................................................................................................................. 14
3.2.5Document Enricher ..................................................................................................................... 14
3.3MapReduce Framework of ConnectinGEO Analyzer ..................................................................... 15
4Accessing Observation Inventory ........................................................................................................ 16
4.1Observation Inventory APIs ............................................................................................................ 16
7.1Observation Inventory Simple Web Client ...................................................................................... 20
8Conclusions ........................................................................................................................................... 21
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
6
Executive Summary
The ConnectinGEO Observation Inventory (OI) is created and populated
using the current information in the metadata concentrated in the GEO
Discovery and Access Broker (DAB) of the GEOSS Common Infrastructure
(GCI) to analyse the observations and measurements currently available in it.
WP4 defined a high-level process for the population of the Observation
Inventory: (i) retrieve the full metadata content for each record in the GEO
DAB, (ii) extract/Infer extra semantics (connecting to external knowledge
systems when needed), and (iii) generate enriched metadata and write it to
the OI.
The OI system architecture was designed and developed. The first version of
the OI was created and populated using the current information in the
metadata concentrated in the GEO DAB. The first population process was run
in December 2015, resulting in a total of more than 1.6M harvested metadata
records.
The developed OI is accessible online and can be used as a data source by
different analysis tools, which create plots, reports, or summary statistics
useful for the ConnectinGEO gap analysis.
A simple Web Client was developed to demonstrate how to interrogate the OI
and provide also basic examples of how the developed OI can be used by
web-based analysis tools.
The developed framework is ready to be extended and complements current
information with data extracted from additional external sources (URR 2.0,
scientific literature DBs, etc.) and the results of ConnectinGEO Task 2.3.
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
7
1 Introduction
ConnectinGEO’s primary goal is to link existing coordinated Earth
Observation networks with science and technology (S&T) communities, the
industry sector and the GEOSS and Copernicus stakeholders. An expected
outcome of the project is a prioritized list of critical gaps within the European
Union in observations and the models that translate observations into practice
relevant knowledge.
The project defines and utilizes a formalized methodology to create a set of
observation requirements that will be related to information on available
observations to identify key gaps.
The gaps in the information provided by current observation systems as well
as the gaps in the systems themselves are derived from five different threads.
One of these threads consists in the analysis of the observations and
measurements that are currently registered in GEO Discovery and Access
Broker (DAB). To this aim, an Observation Inventory (OI) is created and
populated using the current information in the metadata concentrated in the
DAB.
1.1 Scope & purpose of the document
This document describes the process defined to populate the ConnectinGEO
Observation Inventory and the resulting system architecture taking into
account the requirements and database schema from ConnectinGEO
Deliverable 4.1. Finally, this document provides information on how to
systematically access the created OI for performing the gap analysis.
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
8
2 Observation Inventory Population
The high-level process to populate the ConnectinGEO Observation Inventory
(OI), depicted in Figure 1, can be split into three steps:
1. Retrieving the full metadata content for each record in GEOSS DB;
2. Extract/Infer extra semantics, connecting to external knowledge
systems when needed;
3. Generate enriched metadata and write it to the Extended OI DB.
The following sections provide more details about the above steps.
2.1 Getting Full Metadata Content
GEOSS metadata content is stored in a No-SQL DB. The content of this DB is
generated by the GEO Discovery and Access Broker (DAB) when GEOSS
Supply Systems are harvested.
Retrieval of metadata is executed by the GEO DAB components which
read/write content during harvesting phase. This way, full metadata content
(including GEO DAB specific fields) is retrieved and passed to the next step.
Figure 1 - Populating OI: High-Level Process
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
9
2.2 Extract/Infer Extra Semantics
After retrieving the full metadata, this must be enriched by extracting/inferring
additional information. This is achieved by applying the well-known Enricher
design pattern
1
. In a nutshell, this pattern is used when transferring content
from one system (origin system) to another one (target system) and the target
system requires more information than the origin system provides. The
pattern design adds a new component called Enricher. This new component
is in charge of retrieving additional information from external resources,
exploiting original content information if needed (e.g. identifiers, spatial
coverage, etc.). Finally, the Enricher produces the enriched output message
that is sent to the target system.
Figure 3 depicts the application of the Enricher pattern to the Observation
Inventory use case. The origin system is the GEOSS Content DB, thus the
input of the Enricher is the full metadata content retrieved in previous step.
The target system is the OI DB, thus the output of the Enricher is an enriched
version of the metadata content complying with the OI DB schema. The
external resources needed to enrich the content are the ones identified in
ConnectinGEO D4.1, for simplicity only URR is represented in figure. These
external resources are accessed by the GEO DAB, extending its
functionalities where needed. Finally, a set of rules is also present in the
depicted schema. These rules define the business logic implemented by the
Enricher to infer new information.
It is worth to notice that in Figure 3 depicts more than one Enricher. This is
because a set of dedicated Enrichers is envisioned, each one dedicated to
provide additional information of specific type (e.g. accessibility, data type,
measurement, etc.).
1
http://www.enterpriseintegrationpatterns.com/patterns/messaging/DataEnricher.html
Figure 2 – GEOSS Content Metadata Retrieval
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
10
2.3 Generate Enriched Metadata Content
After Enrichers have produced the enriched metadata content, this is written
to OI No-SQL DB by the GEO DAB. To do this, GEO DAB functionalities are
extended to support the new queryable fields required by the OI DB.
Figure 3 – Enriching GEOSS Metadata Content
Figure 4 – Storing the Enriched Metadata Content
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
11
3 Observation Inventory Architecture
To implement the process described in section 2, the ConnectinGEO OI high-
level component architecture depicted in Figure 5 was designed and
developed.
GEOSS OI DB
A new No-SQL DB (the GEOSS OI DB) contains enriched metadata content
of GEOSS OI and is based on the DB schema defined by ConnectinGEO
D4.1.
The GEO DAB can directly read/write the GEOSS OI DB. Therefore, users
can utilize the GEO DAB APIs to access the GEOSS OI DB. These APIs
facilitate the development of web tools accessing the ConnectinGEO content
to create plots, reports, summary statistics, and other useful inputs to the gap
analysis.
ConnectinGEO Analyzer
The ConnectinGEO Analyzer is the component that implements the
enrichment of the provided GEOSS metadata. It achieves the following tasks:
1. To read the actual GEOSS metadata content via the GEO DAB.
2. To enrich the metadata content accessing external knowledge bodies
(see next section)
3. To write the enriched metadata to the GEOSS OI DB via the GEO DAB
functionalities.
GEO DAB
The GEO DAB is in charge of:
Figure 5 – High-Level Architecture of OI
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
12
1. To read the GEOSS metadata content
2. To provide read/write capabilities for the GEOSS OI DB
3. To provide a harmonized access to the external knowledge bodies
needed for the metadata enrichment
In order to connect to external knowledge systems, GEO DAB functionalities
must be extended to broker new types of sources (e.g. URR, scientific
publication repositories, etc.).
3.1 ConnectinGEO Analyzer
The ConnectinGEO Analyzer is the core component to create the enriched
content of GEOSS OI DB. Starting from a GEOSS metadata, the task of the
ConnectinGEO Analyzer is to extract/infer extra information to enrich the
GEOSS metadata. To this goal, the ConnectinGEO Analyzer makes use a set
of Enrichers. Each Enricher is in charge of adding extra information of specific
type (e.g. accessibility, data type, measurement, etc.).
Figure 6 depicts a simplified schema of the process implemented by the
ConnectinGEO Analyzer.
GEOSS metadata content is passed to a pipeline of Enrichers. After the last
Enricher completes its execution, the resulting enriched metadata is stored to
the GEOSS OI DB.
The pipeline of Enrichers can be dynamically configured. This provides a high
flexibility level, which is needed to adapt the enrichment process to the
requirements emerging from the related tasks of the project.
3.2 Enricher Types
Current list of Enrichers and associated development status is shown in Table
1. More Enrichers might be needed in the second development loop
addressing new requirements from related tasks in the project.
Figure 6 – ConnectinGEO Analyzer Process
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
13
Table 1 – Current List of Enrichers
Enricher Type Development Status
Web Resource Enricher Done
Accessibility Enricher Under Test
Record Type Enricher Under Development
Data Enricher Scheduled
Document Enricher Scheduled
3.2.1 Web Resource Enricher
For each of the GEOSS Supply System, this Enricher is in charge of getting
metadata records and creating an enriched version of it with the required
indexed fields as defined by ConnectinGEO Deliverable 4.1.
The GEO DAB action required by the Enricher is the Harvesting of a GEOSS
Supply System.
3.2.2 Accessibility Enricher
The Enricher is in charge of adding accessibility information of incoming
metadata content.
The Record Enricher requires the GEO DAB to check if the referenced links (if
any) in the metadata are accessible and adds this information to the
metadata.
For each referenced link, the specific field that is added by the enricher is one
of the ones listed in the table below.
Field Name Field Value
accessibleLink URL
unaccessibleLink URL
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
14
3.2.3 Record Type Enricher
This Enricher is dedicated to add information about the type of data (e.g.
Essential Variable, Indicator, Indexes, etc.) described by the incoming
metadata content.
To do this, a set of tags is extracted from the metadata content. The tags are
then used to determine the described data type based on information from
external knowledge systems (e.g. URR) accessed by the GEO DAB.
The specific field that is added by the enricher is one of the ones listed in the
table below.
Field Name Field Value
EV EV Name
Indicator Indicator Name
Index Index Name
3.2.4 Data Enricher
The task of the Data Enricher is to add information about the data (if
accessible) referenced by the metadata.
The GEO DAB is invoked here to download the referenced data and provide
related information (e.g. protocol used to access the data, format of the data,
etc.).
For each referenced data that is downloadable, the specific fields added by
this enricher are listed in the following Table.
Field Name Field Value
ServiceProtocol Protocol of the access service
DataFormat Data format of the downloaded data
DownloadURL The URL to download the data
3.2.5 Document Enricher
The task of the Document Enricher is to add information about the document
(if accessible) referenced by the metadata.
The GEO DAB is invoked here to download the referenced document and
provide related information (e.g. web page, scientific publication, etc.).
For each referenced document (if accessible), the specific field that is added
by the enricher is one of the ones listed in the table below.
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
15
Field Name Field Value
documentFormat WebPage, PDF, etc.
documentType ScientificPublication,
TechnicalReport, etc.
3.3 MapReduce Framework of ConnectinGEO Analyzer
Due to the dimension of the GEOSS Metadata DB (millions of entries),
Hadoop MapReduce
2
was selected as the framework to run the
ConnectinGEO Analyzer.
The process described in section 2 is implemented as a MapReduce job
running on a Hadoop cluster. Figure 7 depicts a simplified view of the
MapReduce implementation.
In the MapReduce framework, the input of a job is split into a set of InputSplits
and each InputSplit is processed by a Mapper. Each InputSplit is divided into
records, and the Mapper processes each record. InputSplit is basically a list of
records to be processed by one Mapper. This input-splitting process is used
by the MapReduce framework to parallelize the execution of the job. In fact,
2
http://hadoop.apache.org
Figure 7 – Implementation of OI Population in MapReduce
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
16
after creating the InputSplits, these can be processed in parallel according to
the availability of resources in the MapReduce cluster.
In the ConnectinGEO Analyzer use case, where the input of the job is the
entire GEOSS metadata content, the framework implements an ad hoc splitter
(which can be configured to generate a variable number InputSplits). This is in
charge of reading a subset of GEOSS Metadata Content DB (step 2.1) and
pass it to the Mapper.
A Connecting GEO Analyzer Mapper invokes a configurable list of Enrichers
that work on a single metadata document (step 2.2). After all Enrichers have
been executed the Mapper writes the output to the new DB (step 2.3).
Finally, it is worth to notice that presently no Reducer is used by the
ConnectinGEO Analyzer framework. In fact, Reducers in MapReduce are
used to aggregate/sort output of Mappers, which is not the case for the
defined MapReduce job.
4 Accessing Observation Inventory
The developed OI is accessible by client applications using the GEO DAB
supported interfaces
3
.
In order to support the ConnectinGEO gap analysis, the OI content can be
accessed by means of the GEO DAB JavaScript APIs
4
. Such APIs allow web
applications to easily interrogate the OI. This way, web-based analysis tools
can provide useful views and statistics of currently available observations
from GEOSS can exploit the content of the OI.
Besides, an ad-hoc extension to the GEO DAB APIs was introduced in order
to use JavaScript for submitting complex queries (i.e. with nested logical
operators) to the OI. This is described in the next section.
4.1 Observation Inventory APIs
GEO DAB APIs allow combining different queryable fields with AND relation
only; besides, it is not possible to create nested logical groups of constraints –
e.g. [keyword=’temperature’ AND (title=’air’ OR title=’sea’)].
To support gap analysis tools, such functionalities are very important since it
might be needed to create complex queries taking into account observation
requirements from the project related tasks.
3
http://www.geodab.org
4
http://api.eurogeoss-broker.eu
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
17
To support this requirement, an extension of GEO DAB APIs was developed.
GEO DAB APIs have a defined extension point: the key-value-pair (KVP)
parameter of the GEO DAB APIs discover method
5
. In addition to the
documented values which can be passed using the kvp parameter, the OI
supports the following JSON
6
encoding of complex queries:
jsonquery:{ "condition": "AND" | "condition": "OR",
"rules": [rule1, rule2,.., ruleN]}
where
rule:{ "condition": "AND" | "condition": "OR",
"rules": [rule_1, rule_2,.., rule_N]}
or
rule: {"id": "QueryableID",
"type": "QueryableTYPE ",
"operator": "QueryableOPERATOR ",
"value": "ConstraintValue"}
Thus the example query [keyword=’temperature’ AND (title=’air’ OR
title=’sea’)] is encoded as in the following
jsonquery:{ "condition": "AND",
"rules": [{"id": "apiso:keyword",
"type": "string",
"input": "text",
"operator": "contains",
"value": "temperature"},
{"condition": "OR",
"rules": [{"id": " apiso:title",
"type": "string",
"operator": "contains",
5
http://api.eurogeoss-broker.eu/docs/classes/DAB.html#method_discover
6
http://json.org
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
18
"value": "air"},
{"id": " apiso:title",
"type": "string",
"operator": "contains",
"value": "sea"}]
}]
}
For each queryable field, Table 2 lists the QueryableID, QueryableTYPE and
the list of supported QueryableOPERATORs. This list might be subject to
change in the second loop of development, an updated version will be
published online on the Simple Web Client page (see next section).
Table 2 – Queryable Fields, Types and Supported Operators
Field Queryable ID Queryable
Type 5 Supported
Operators
6 Value
Form
at
Abstract apiso:abstract string contains
Area apiso:BoundingBox string
is_contained,
disjoint, overlaps
±
nn.nn;
±
ee.ee;
±
ss.ss;
±
ww.ww
Time Extent
Begin apiso:TempExtent_begin date
less,
less_or_equal,
greater_or_equal,
greater
YYYY-
MM-DD
Time Extent
End apiso:TempExtent_end date
less,
less_or_equal,
greater_or_equal,
greater
YYYY-
MM-DD
Essential
Variable essi:EVname string contains, equal
Access Link essi:HasAccessLinkage string equal Yes | No
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
19
Other Link essi:HasOtherLinkage string equal Yes | No
Identifier iso:identifier string equal
Keyword apiso:keyword string contains, equal
Legal Access
Constarints essi:CNT.Leg.Access string contains, equal *
Legal Other
Constarints essi:CNT.Leg.Other string contains, equal *
Legal Use
Constarints essi:CNT.Leg.Use string contains, equal *
Measurement gvq:MeasureDescription string contains, equal
Parent
Identifier apiso:ParentIdentifier string contains, equal
Producer
Name apiso:Creator string contains, equal
Published apiso:PublicationDate date
less,
less_or_equal,
greater_or_equal,
greater
YYYY-
MM-DD
Resolution iso:GMI.BandResolution double
less,
less_or_equal,
greater_or_equal,
greater
Theme apiso:subject string contains, equal
Title apiso:title string contains, equal
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
20
Topic
Category iso:TopicCategory string contains, equal
Use
Limitation essi:CNT.UseLimit.text string contains, equal
* These fields can be used both as Boolean and as Text matching fields. The format is
type;;value
Where type is one of true, false or text. When type is text, the field works as a
Text matcher, and all records containing the string in value are accepted. Below
is a rule example for this case, all records containing the text “copyright” in the
Access constraint field will match:
{"id": "essi:CNT.Leg.Access", "type": "string", "operator": "contains", "value":
"text;;
copyright"}
Otherwise, the field works as a Boolean field and all records containing (if
type=true) or not containing (if type=false) the corresponding metadata element
are accepted. Below is a rule example for this case, all records containing the
any text in the Access constraint field will match:
{"id": "essi:CNT.Leg.Access", "type": "string", "operator": "contains", "value":
"true;;undefined"}
7.1 Observation Inventory Simple Web Client
A simple Web Client was developed to interrogate the OI. The objective of this
web client is to allow a basic exploration of the OI content. It is possible to
query the OI using the available queryable fields (as defined by
ConnectinGEO Deliverable 4.1). The Web Client makes use of the above-
described extension of the GEO DAP APIs to submit complex queries to the
OI.
Figure 8 depicts a screenshot of current Web Client showing the results of a
query.
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
21
The Simple Web Client is available at
http://oi.geodab.eu/oi-client/home/
8 Conclusions
WP4 defined a high-level process for the population of the Observation
Inventory (OI). Based on this process, the architecture for the creation of the
OI was designed and developed.
The first version of the OI was created and populated using the current
information in the metadata concentrated in the GEO Discovery and Access
Broker (DAB) of the GEOSS Common Infrastructure (GCI). The first
population process was run in December 2015, resulting in a total of more
than 1.6M harvested metadata records.
The developed OI is accessible online by client applications using all service
interfaces supported by the GEO DAB, including JavaScript APIs with an ad
hoc extension to execute complex queries. This way, it is possible to use the
OI as a data source for different analysis tools, which create plots, reports, or
summary statistics useful for the ConnectinGEO gap analysis.
A simple Web Client was developed to demonstrate how to interrogate the OI.
In the “Documentation” section, the Simple Web Client provides also basic
examples of how the developed OI can be used by web-based tools to
provide views and statistics of currently available observations useful for the
gap analysis.
Figure 8 – Simple Web Client of OI
H2020ProjectNr:641538.Projectstartdate:01Feb2015
Acronym:ConnectinGEO
Projecttitle:CoordinatinganObservationNetworkofNetworksEnCompassingsaTelliteandINsituto
filltheGapsinEuropeanObservations
Theme: SC5‐18a‐2014. Coordinating European Observation Networks to reinforce theknowledge base for
climate,naturalresourcesandrawmaterials
22
Figure 9 depicts one of these examples. Taking into account all records
containing “temperature” in the metadata abstract field, three charts are
created: the first showing which ones have access constraints, the second
one showing which records cover a spatial extent inside Europe, and the third
one their distribution across GEOSS former SBAs.
Finally, the developed framework is ready to be extended and complement
current information with data extracted from additional external sources (URR
2.0, scientific literature DBs, etc.) and the results of ConnectinGEO Task 2.3.
Figure 9 – Simple Web Client Example
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