Implementation through European

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Implementation through European

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Title: Implementation through European

1
State of the art Technologies for GIS Management
Systems

Implementation through European
Community Research Projects

Lykiardopoulos Angelos, Iona Athanasia, Lakes
Vasilis, Balopoulos Efstathios, Kalkavouras
Constantine
Hellenic Center for Marine Research
2
Data Management Historical Brief
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

At the end of 80s and early 90s several
Oceanographic Data centers had created Databases
with mass storage of spatial Information which
concerned Oceanographic research outcomes. This
was en enormous step of digital storage because
big data volumes organized in Database Systems.

In other words the data centers owned databases
Based on various RDBMS mechanisms
With their own database Schemas
With their own data vocabulary (if existed)
With raw data in various formats
With Applied various processes of data quality
control (or with no data quality control)
This effort of course leaded into the creation of
several data bases without any Interoperability
among them.

But the oceanographic community had the need of
homogenized and comprehensive data sets for
various regions and even world wide.
Due to the limitations of information
technologies this goal was achieved in the
framework of several E.U. projects
Central accumulation of data from various Data
Centers took place
Data sets were processed in common data formats
and more or less same Q.C. procedures.
Finally the dissemination of these Data sets was
carried out mainly via digital media (CD-ROMs,
etc).

During this process
Diverse Data form a wide range of Data Centers
were gathered.
Common homogenization and QC procedures were
passed.
And finally some comprehensive Data sets were
produced and disseminated.
But
The produced Data Sets were stand alone products
stored in digital media.
Without any dynamic mechanism of maintenance and
enhancement.
And without any online access.

Thus, the idea of a distributed Oceanographic
Data network among the Data Centers started
growing up.
Since Web technologies were being developed
rapidly, became apparent that the above network
has to be web based.

FUTURE The new architecture An example Conclusions
7
Main obstacles
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

The main obstacles that came through for this
idea to be fulfilled were
Data bases were in different Schemas and
Technologies specific per Data center so there
was not any common data interchange mechanism.
Data were not homogenized among Data centers.
Data quality and Data vocabulary differed from
Database to Database

At the same time another obstacle was that due to
premature Data Base technology many RDMBS systems
lacked spatial capabilities.
So it was very difficult for the end user
To query the Database with spatial criteria
To represent geographically the spatial
information and produce geospatial products
To work interactive with Geo Data through
interfaces with geospatial capabilities
To combine geospatial data with synthetic data
products
Hence, for a distributed Oceanographic Data
network to be established, the necessity of GIS
enabled Databases to become apparent as well.

At the end of 90s most of the common used RDBMS
were enriched with spatial capabilities and
became then powerful mechanisms of integration,
exploitation and presentation of spatial
information
Oceanographic data centers, exploited this
advantage and started upgrading their databases

But still the luck of interoperability was
unsolved. The spatial databases made researchers
life easier with regard to querying data or
representing graphically geospatial information
but they were acting without any interconnection
among the various Data Centers.

At the same time with the efforts of the
Oceanographic community to overcome the obstacle
of interoperability of diverse data management
systems and during the last five years new
technologies instead of traditional web access
tools aroused and became common known as
Web Services

PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
12
Summarizing the historical brief throughout
important E.U. projects
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
SEA DATA NET
MEDATLAS
1994
1998
2002
2006
SEASEARCH
MEDAR/MEDATLAS II
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.

Enrichment of existing data sets
Establishment of common protocols in QC and
formatting
Enhancement of communication facilities (www,
ftp, e-mail etc)

Efforts in QC
Data homogenization
Centralized management
Distribution with CD ROMs

Development of a pan-european network for ocean
and marine data information management.
Improve the exchange, availability and
accessibility of ocean marine data and
information.
Expand the online metadatabases with input of
research institutes.
Improve the online accessibility of Sea-Search
services products.

To network existing oceanographic data centres
already nationally funded.
To develop an efficient distributed pan-European
marine data management Infrastructure (virtual
data center).
To provide on-line access to integrated databases
of standardised quality by using adapted
communication information technology (Web
Services).

FUTURE The new architecture An example Conclusions
13
Web Services fundamentals
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

First of all what is a Web Service?
The hidden idea behind WS is the existence of a
universal messaging mechanism, capable to deliver
and translate messages for diverse and different
systems.
This feature came to open the road for the
solution of interoperability.
If different and diverse systems can interpret
and process requests from each other let them
stay different.

There are various theoretical definitions of What
a Web Service is
A software system designed to support
interoperable machine-to-machine interaction over
a network. It has an interface described in a
machine - processable format (specifically WSDL).
Other systems interact with the Web service in a
manner prescribed by its description using SOAP
messages, typically conveyed using HTTP with XML
serialization in conjunction with other
Web-related standards. (W3C, 2004)

Web services are a distributed computing
architecture. Only this particular architecture
makes use of loosely coupled applications, as
opposed to tightly coupled applications, to
enable applications to communicate. This tightly
coupled concept radically affects how information
systems will work in the future
(Clabby 2003)

Generalizing we may define that Web services
provide a convenient and standardised way of
exposing business logic over a network (the
Internet) by use of specific components of
communication such as
SOAP,UDDI,WSDL

UDDI (Universal Description, Discovery and
Integration) which provides the ability to
dynamically select a service at runtime.
SOAP (Simple Object Access Protocol) which
provides a Standardized messaging structure based
on XML.
WSDL (Web Services Description Language) which
describes how the client communicates with a Web
service or what a service does or where is
located.

In the most simple form a web service
architecture may be depicted as the diagram

The rapid development of technologies towards WS
concept has produced several sets of Web Services
with regard to the area of the WS applicability.
Especially for Geospatial data, Open Geographical
Consortium (OGC) has defined two basic sets of
Geospatial Web Services.

The Web Map Services (WMS) which are concerned
with transforming spatial data into maps
(images).
The Web Feature Services (WFS) which are
concerned with direct access to data - reading,
writing, and updating data.

FUTURE The new architecture An example Conclusions
21
Web Processing Services
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

Furthermore, more Web services are under
finalization process, one of the most important
of them is Web Processing Services
WPS is designed to standardize the way that GIS
calculations are made available to the Internet.
WPS can describe any calculation (i.e. process)
including all of its inputs and outputs, and
trigger its execution as a Web Service. WPS
supports simultaneous exposure of processes via
GET, POST, and SOAP, thus allowing the client to
choose the most appropriate interface mechanism.

The HNODC data management case.

FUTURE The new architecture An example Conclusions
23
HNODC
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

Hellenic National Oceanographic Data Center
(HNODC) is a National Public Oceanographic Data
provider and at the same time a member of the
International Net of Oceanographic Data Centers
(IOC/IODE)
HNODC owns a very big volume of Data and Relevant
information about the Marine Ecosystem

For the efficient management and exploitation of
these Data, the first step was a relational Data
Base to be constructed.
After the necessary stage of data quality control
took place, following the International
standards, as they agreed during several EU
Projects or International Organizations.
Finally a mass volume of over 300.000 station
data concerning , physical, chemical and
biological Oceanographic information, was stored
in a Relational Data Base.

The next target aroused then, was an Application
to be constructed capable to represent
- the Geospatial aspects of this information
- together with the non spatial information
The necessary analysis took place and a
traditional Web Application was developed by the
use of the convenient web tools and
technologies.
Geographical representation was achieved by the
use of a Middle Layer tool (ArcIMS) over the Data
Base Mechanism.

The convenient Multilayer Architecture was
followed
The Relational data base as the back end.
ArcIMS as the Geospatial representation
Mechanism.
Apache and Tomcat in heart of the Middle-Tier
System.
On the top a web Interface with selection
criteria for querying specific data sets in
specific geographical areas.

PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
27
HNODC - Architecture
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
28
HNODC Web page
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
29
HNODC
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

Concluding we may say that the whole Architecture
, served its purpose to
Handle data management issues
Expose data dynamically to the web
Offer user easy and online data access
Represent geospatial information graphically

Of course some technical issues aroused,
regarding the Applications performance, due to
the inefficiency of the Geographical mechanism to
handle big volumes of data sets as fast as a Web
Application needs.
For HNODC this approach is today considered as
the first Version (V1) of an Integrated Web Based
Environment for its Data Management and Data
exploitation.

Thus and at the time that Web Services became a
fact, a second Version was planned
The target of this effort was an Integrated
environment to be developed following at least
the basic concepts of a Service Oriented
Application (SOA) which are
The interface contract to any Web Service is
platform-independent.
Any Web Service can be dynamically located and
invoked.
Any Web Service invoked is self-contained. That
is, the service maintains its own state.

For the development, new software components and
tools replaced the old ones
Geospatial and non Spatial Web Services
mechanisms took the place in the Middle- Layer.
Geospatial open source tools and custom
development was employed in presentation layer.

At the same time the application may now
interact with any other SOA application either in
sending or receiving Geospatial Data, since it
inherits the big advantage of interoperability
between Web Services systems.

The Architecture can be denoted as follows
At the back End Open source PostgreSQL DBMS (and
not only..) stands as the data storage mechanism.
UMN Map Server and Geoserver are the mechanisms
for
Representing Geospatial Data via Web Map Service
(WMS)
Querying and Navigating in Geospatial and Meta
Data Information via Web Feature Service (WFS)
And in the near future Transacting and processing
new or existing Geospatial Data via Web
Processing Service (WPS)

MapBender, a geospatial portal site management
software for OGC and OWS architectures, acts as
the integration module between the Geospatial
Mechanisms.
MapBender comes with an embedded data model
capable to manage interfaces for displaying,
navigating and querying OGC compliant web map and
feature services (WMS and transactional WFS).

Apache and Tomcat stand again as the Web Service
middle Layers
Apache Axis2 with its embedded implementation of
the SOAP protocol acts as the No spatial data
Mechanism of Web Services. These modules of the
platform are still under development but their
implementation will be fulfilled in the near
future.

And a new Web user Interface for the end user
based on enhanced and customized version of a
MapBender GUI.

PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
38
HNODC - Architecture
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
39
HNODC Web Interface
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
40
HNODC Web Interface
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial
PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
41
HNODC Web Services
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

For HNODC the interoperability of Web Services is
the big advantage since it is capable to act in
the future as provider and consumer of Web
Services in both ways
Either as data products provider for external
SOA platforms. (e.g. SeaDataNet platform)
Or as consumer of data products from external
SOA platforms for new applications to be
developed or for existing applications to be
enhanced.

Further more and when the technology of Web
Processing Service (WPS), will be mature enough
and applicable for development, the derived data
products will be able to have any kind of GIS
functionality for consumers across the network.

A good example of the previous architecture,
is the Oil spill Drift forecasting Use Case
Scenario for Aegean sea.

FUTURE The new architecture An example Conclusions
45
An implementationThe Oil Spill Scenario
PAST Historical Brief Centralized D.M. From
Centralized to Distributed Model From Non Spatial
to Spatial

Several and diverse Data Sets will be used as
inputs in the scenario Application
ASAR satellite images
Oceanographic data
Wave model (WAM) data
Textual Information
GIS data about the nearby coasts layout (roads,
urban or protected areas etc)

The scenario aims to deliver to the end user
synthetic information in near real-time
regarding
Details about oil spill detection
Forecasts about the drift of the oil spill.
Additional information about the characteristics
and the infrastructure of the nearby coast area
The scope of the scenario is to provide the
decision makers with all the necessary
information to handle the crisis
The output of the Application will be Synthetic
GIS and non GIS information
Either via Map images presentation
Or textual information
Web Services will be present as discrete Layers
of Information (input or output) from the
different
Data Sources

A big obstacle aroused was the Harmonization of
the
various datasets.
Here comes E.U. HUMBOLDT Project which will
contribute to harmonization since it aims to
make an inventory of the data harmonisation
issues in the Scenario,
assess their importance in the Scenario
create Scenario-specific data model,
develop harmonization software tools

In conclusion we may denote that by embedding
these new technologies to data management model
we can exploit the advantages of
Inheriting interoperability between among Data
Centers and Data Providers
Interchanging and combining Data Sets with
minimum programming efforts
Producing comprehensive and self explained new
Data Products combing various and diverse data
sources
Helping end user to navigate through a wide range
of information

Thus we are happy to say that HNODC joins the
global scientific community by providing and
consuming application Independent data products.

PRESENT Web Services W.S. Architecture Geospatial
W.S. WMS/WFS WPS HNODC General HNODC
Architecture HNODC Interface HNODC W.S.
FUTURE The new architecture An example Conclusions
51
The end