Transcript Lecture Note Geoportal File - e

Web based GIS 4583
Nurul Hawani Idris
Geoinformation Department
Universiti Teknologi Malaysia
2013/Sem 2
Geoportal
• An increased amount of geospatial data is being collected by
virtue of more user generated contents on the Web, in addition
to data from satellites, ground, and ocean sensors, and GPS
units (Goodchild, Fun and Rich 2007)
• Geoportal– websites where GI can be discovered – make it
easier for users to find, access, and use GI
• Emerged in the mid 1990s – as an important part of their SDI
• Geoportals are a type of Web GIS app
• Facilitate data sharing, and provide resources for developing
other Web GIS app
Gateways to GI
• Derived from the Latin word porta, indicating a doorway – a
web portal @ portal – a website that functions as an entry
point to the WWW. A portal provides search tools that help
users find information on the Web, and it usually also provides
categorised links to many online resources
• Web portals provide an easy, direct means of indexing ,
ordering and displaying information.
• Examples of Web portal ? ? ?
• Web portals saved the Web from being bogged down in a sea
of data and have played a significant role in the success and
popularity of the Web (Tang and Selwood, 2005).
Gateways to GI
• Web portals can be classified by their range of contents –
general (or horizontal) portals versus specialised (or vertical)
portals.
• A geoportal – prefix ‘geo’ – specialised in GI
• Also referred to as a spatial portal, - website that provide a
single point of access to geospatial data, web services, and
other geospatially related resources
• A website where geospatial resources can be discovered (Tait
2005)
• A gateways to GI, facilitate GI sharing between providers, who
own the information, and users, who need the information
Gateways to GI
• GI providers - publish the metadata of geospatial data, web
services, and documents
• Users – browse or search through geoportals to find relevant
geospatial resources and evaluate their applicability. Then
download the online data, connect to and use Web services, or
contact the content provider for offline data or documents
Geoportal
Publish metadata
Provider
Search and discover
Contact, acquire,
download, connect, use
User
Gateways to GI
• The uniqueness of geoportal
1)
2)
The ‘face’ of SDI
• GI is vital to making sound decisions at the local, regional,
national and global levels. It is crucial to address the issues
related to social, economic and environmental issues
• Many are not motivated to share their data with others
• This creates isolated islands of information – make difficult for
organisation to discover and obtain the data they need
• In turn leads to
1)
2)
3)
4)
5)
The ‘face’ of SDI
• SDI – basically the technology, policies, standards, and human resources
necessary to acquire, process, store, distribute and improve the use of
geospatial data
• SDI can be at global level (GSDI), national level (NSDI), regional level or local
level.
• The primary objective : to max the overall use of GI that is held by a wide
range of stakeholders in both the public and private sectors
• Geoportals have been developed as a major part of SDI. Why ?
• Without geoportals, what will happen?
• A month to make phone calls, write letters and emails
• Physically travel to a place to inquire about the existance of data held by
another agency
• Then to verify whether the data addresses the intended use.
The ‘face’ of SDI
• Geoportal – as a broker between the data provider and the users –
and become the important and highly visible components of SDI,
serving the face of SDI
• In the past decade, more than 100 countries have embarked on some
form of SDI initiatives
• National Geoportal Data Clearinghouse (FGDC and USGS) at US.
1990s – 2003
• Geospatial one stop (GOS) portal – president bush – enhanced the
NGDC portals, centralised architecture, improve performance,
support open standards – 2002
• Data.gov – Obama – to increase ability of public to find, download,
and use datasets that are generated and held by the federal govt.
Geospatial data is the main content, supported by GOS - 2009
The ‘face’ of SDI
• NASA’s Global Change Master Directory (GCMD) – gives user access
to Earth science dataset and to service that a re relevant to global
change and earth science research.
• Mississippi Geospatial clearinghouse
• Arkansas GeoStor
• Kentucky Watershed Modeling Information portal
• ESRI – Geography Network geoportal (2000) - web services discovery
and dynamic composition
• Replaced by ArcGIS Online and ArcGIS.com
• In Canada, Geoconnection program – component of Canadian
Geospatial Data Infrastructure – to share GI in 4 priority areas –
public safety, public health, aboriginal community affairs,
environment and sustainable development
The ‘face’ of SDI
• Australia and New Zealand Land Information Council (ANZLIC) led
the implementation of the Australian Spatial Data Infrastructure
(ASDI). A key component – Australian Spatial Data Directory
• Europe – Infrastructure for Spatial Information in Europe (INSPIRE)
initiative launched in 2001.
• Aim to build a European SDI that goes beyond national boundaries
• Fully implementation required by law in 2019
• The INSPIRE directive requires the European commission to establish
a community geoportal where member states will provide access to
their infrastructure through this main geoportal, and through any
access points they decide to operate and maintain
• Need to address the differences in language, business practices and
cultural affairs of its members.
MyGDI
• Malaysia Geospatial Data Infrastructure (MyGDI) - is an
initiative by the government to develop a geospatial data
infrastructure
• to enhance the awareness about data availability and improve
access to geospatial information. This can be fulfilled by
facilitating data sharing among participating agencies
• Through its application MyGDI Explorer, - facilitates online
access to geospatial information
• It provides a base for geospatial data exploration, evaluation,
and application for users and data providers within all levels of
government, commercial, and non-profit sectors as well as the
academia and the public.
MyGDI
• In the Malaysia contexts, SDI initiatives started from the
national level and is expected to filter down to all the states
and gradually to all local levels.
• MyGDI objectives
• To assist in the sharing of geospatial information between
agencies by providing the latest state-of-the-art information
technology hence allowing the dissemination of current and
accurate information.
• To prevent redundancies of effort in collecting, processing,
maintaining, preparing and distributing of geospatial
information among related agencies.
MyGDI
• The goal of MyGDI is to enable members of the geospatial
community to share and access their geospatial data.
• MyGDI facilitates online access to geospatial information, avoid
duplication of effort in the collection of data and to ensure the
accuracy, timeliness, correctness and consistency of data to be
used in planning, development and management of land
resources by:
• providing a mechanism to facilitates the utilisation and sharing
of geospatial data among the agencies that use and supply the
data
• encouraging wider use of geospatial data at the state and
national levels
• stimulating and enhancing the awareness about the value of
geospatial data and the relevant technology
MyGDI
• stimulating and enhancing the awareness about the value of
geospatial data and the relevant technology
• contributing towards strenghtening the development of
national geospatial data through collaboration.
Governance Structure of MyGDI
• Committee Members:
• Chairman: Secretary General, Ministry of Natural Resources and
Environment
• Deputy Chairman: Director General of Survey and Mapping Malaysia
• Secretary: Director of Malaysian Centre For Data Geospatial
Infrastructure (MaCGDI)
• Members :
• Central agencies namely MAMPU, EPU, ICU and Treasury.
• Director General of Departments and Federal Agencies
• All Chairman for MyGDI State Coordinating Committee
• Chairman of Technical Framework Committee.
• Chairman of Technical Clearinghouse Committee
• Chairman for all MyGDI State Technical Committee
• And other agencies as periodically required
• Secretariat: Malaysian Centre For Data Geospatial Infrastructure MaCGDI)
Components
MyGDI Data Categories
Aeronautical
This category contains
geospatial information
related to air
transportation such as air
space, aerodrome and
airport.
Built Environment
This category contains
building, property or place
designated for use as
premises for residential,
commercial, industrial,
institutional, educational,
religious, recreational,
cemetery and built-up
structures.
Demarcation
This category holds
information on
delimitation/delineation
of topographic, maritime
and cadastral features.
Geology
This category includes all
geological mapping
information and the
related geoscience
geospatial data including
geolithology, mineral,
fossils, mining,
exploration, and
geological features.
MyGDI Data Categories
Hydrography
This category includes
geospatial data on coastal
hydrography, shoreline
structures, fishing facilities,
ports and harbours,
navigation aids, danger and
hazard, depth information,
inland water, river
structure, offshore
information.
Hypsography
This category contains the
geospatial information
related to spot heights,
contours, altimetric data
and gravity data.
Soil
This category contains
geospatial information
related to soil classification
such as Histosols,
Spodosols, Andisols,
Oxisols, Vertisols, Ultisols,
Mollisols, Alfisols,
Inceptisols and Entisols.
Transportation
This category contains both
land and water
transportation geospatial
information such as road
network, rail line, water
route and jetty terminal.
MyGDI Data Categories
Utility
This category contains the
geospatial information
related to electricity,
telecommunication, water
supply, oil and gas,
broadcasting, sewerage and
waste management.
Vegetation
This category includes
geospatial data on
agricultural land use
activities, boundaries and
areas of vegetation such as
forest, mangrove, wetland,
dryland and cropland.
Special Use (Specific
Dataset)
This category contains the
geospatial information
related to terrain analysis
dataset, meteorological
dataset such as temperature
and rainfall isoline,
orthorectified images,
digital elevation model and
geoid surface.
General
This category includes
monumented control points
such as geodetic control
station, benchmarks, tide
station, standard traverse
marks, ground control point,
gravity station and remote
sensing imagery such as
aerial photography and
satellite imagery
Functions and Architectures
• Geoportals should provide typical functionality suitable to each
of the 3 roles – publisher, administrator, and users
Administrator
Publisher
Register account
Create metadata
Publish metadata
Secure metadata
Manage account,
metadata, security….
User
Search for resources
View metadata
Download data
View map services…
Functions and architectures
Publisher
• Provides content to the geoportal. Functionality offer by
geoportal to this group:
 Creating account – sign up, join certain groups
 Creating metadata – help creating metadata that complies
with certain standards
 Publishing metadata – helps contribute to the portal catalog
 Securing metadata – allows publisher to specify whether
their metadata is public of only accessible to certain groups
 Other functions – registering metadata repositories to be
harvested
Functions and architectures
Administrator
• Manage content in the geoportal. Geoportals offer this group
the following functionality:
 Managing account – allow admin to review accounts,
approve or disapprove requests to be publishers, and to join
certain groups
 Managing metadata – allow admin to review metadata
records that are published and approve/disapprove them
 Managing security– assists admin in reviewing the privileges
of each group and configuring the contents that each group
can access
 Other functions – including managing harvesting and
ensuring that harvesting occurs as scheduled
Functions and architectures
Users
• Users search for contents that meet their needs. Geoportals
offer this group the following functionality:
 Searching metadata– provide an interfaces for users to
specify criteria such as what (keywords, content type, or
format), where (spatial extent, location information), and
when (temporal range), and then searches the metadata
catalog and returns the matching records in a list of sorted by
relevance or other properties
 Viewing Managing metadata – allow users to view metadata
discovered in its original format or transformed formats,
which are usually easier to read
 Downloading data– provide links to allow user to download
the resources just discovered
Functions and architectures
Users
• Users search for contents that meet their needs. Geoportals
offer this group the following functionality:
 Viewing map services and using web services – allow users to
preview individual map services or create composite maps
with the use of a map viewer
 Other functions – including creating accounts, managing
personal profiles, saving certain search criteria, saving
created maps, creating composite maps, and notifying users
when relevant metadata is published or added to the portal
Metadata standards
• Geospatial metadata – refers to the information that describes geospatial
data, web services or other geospatial resources
• Usually presented in XML format, represents the ‘who, what, when, where,
why, and how’ of a piece of geospatial data or other resource
• object level metadata – describe a single entity,
• collection level metadata, which describe a series or group of entities
• Geospatial metadata usually includes:
–
–
–
–
–
Identification – dataset title, citation, abstract, purposes, keywords
Quality – positional accuracy, data completeness, consistency
Spatial reference – coordinate system and spatial extent
Temporal information – date the data was acquired, the length of time the data is valid
Distribution information – distributor, options for obtaining the datasets (format of
resources, URL used to download the data/access Web services
Metadata standards
• Metadata is useful in data archiving, assessment, management,
discovery, transfer, and distribution
• In geoportal context, metadata has the following uses:
 Discovery of resources – similar to a library catalog. Enables user
to specify search criteria that goes beyond the author, title, and
keywords. Geoportal can search the metadata catalog, and
return matching records, and details of how to access, whom to
contact to
 Evaluation of resources – once discover, user need to determine
whether it will fit a given use – spatial resolution? Meet the
quality? Any restriction on usage?
Metadata standards
• In geoportal context, metadata has the following uses:
 Use of resources – metadata includes technical specifications..
Dataset volume, data format, type of web service, software tool
to handle the resources
 Contact between the user and the provider (publisher)–
provider can disclose the terms of use – limit of web services
per day, the right to discontinue the service, copyright
attribution requirement, limitation of liability. When there are
disputes or copyright infringement, the data provider can avoid
legal responsibilities or claim copyright
Metadata 2.0
• In the era of Web 2.0, content sharing is not limited to the
scientific and professional community
• Everyone who is willing to share their content should be able to
do so
• This lead to metadata 2.0 – the needs of metadata that usercentric, easy for contributor to create, and easy for users to
understand
• Tags – represent a move towards metadata 2.0
• Keyword or term that describe and item – photo, video, a tool.
• Tags can be considered as a bottom up type of classification
compared with the traditional hierarchical system of metadata
standards, which are top down
Metadata 2.0
• Tags allow contributors to quickly share information
• Such metadata is often informal and incomplete
• Yet tags let users quickly evaluate resources to see if it’s what
they’re looking for
• On website, the opinions of others about a resource become
an integral part of its metadata- albeit informal metadata –
customer review
• Different type of metadata are needed for different uses
• Metadata 1.0 is still important in enabling professional and
organisation to document their GIS information assets, and to
discover and evaluate the applicability of asset for certain
users, a metadata 2.0 encourages broad participation in the
sharing of information
Challenges and Prospects
• Geoportals facilitate the sharing of information, eliminate
duplicate data collecting, and support more rational decision
making
• Hurricane Katrina and Rita in US 2005, data providers quickly
established virtual communities in GOS (Geospatial One Stop)
(www. geodata.gov) and contributed critical information,
including data, map services, online map viewers app.
• To aid federal, state and local agencies in emergency response
activities.
• In China, the Geoportal of Earth Science Data Sharing Network
supported the design and construction of the Qinghai-Tibet
Railway, emergency response for the 2008 Wenchuan
Earthquake, and environmental protection for 2008 Beijing
Olympic Games
Challenges and Prospects
• Further development of geoportals faces a number of challenges:
• Handling the complexity of metadata standards
 It is not uncommon to hear ‘ metadata is too complex’, and ‘I don’t
have the time and funds to create metadata’ - obstacle to publishing
data quickly, and sharing information
 The decision of whether to comply with metadata standard remains a
difficult choice – informal? ISO? Dublin Core? FGDC metadata CSDGM
 Software vendors can provide tools that simplify or even automate
the creation of standard metadata
 E.g. transform metadata into HTML and GeoRSS formats which can
increase the exposure of metadata for easier discovery and broader
accessibility
 E.g. use simple metadata tags
Challenges and Prospects
• Further development of geoportals faces a number of challenges:
• Supporting Semantic Search
 Refer to a search based on the meaning of keywords rather than the
spelling of keywords.
 At present – unable to account for the meaning of keywords, the
context in which keywords are used, and the ambiguities of natural
languages.
 A strict keyword search – will not satisfy the needs of a thorough
intelligent search
 E.g. search river – channels, lakes, streams related to hydrology
 Search that rely on a matched string may miss records that users
really want
 Support semantic search by incorporating OWL (Web Ontology
Language)
Challenges and Prospects
• Further development of geoportals faces a number of challenges:
• Supporting Semantic Search
 Ontology Is a formal representation of a set of concepts within a
domain and the relationships among these concepts
 OWL is a family of language for representing ontologies
 GEMET (General multilingual Environmental Thesaurus) developed by
the European Topic Center on Catalog Data
 More than 6000 terms and defines the relationship among terms
 Semantic search will search OWL, find related terms, (synonym,
narrow terms) then searches the catalog for record matching these
terms rather that just the term requested
GEMET OWL (River)
Channeling
Water
Hydrosphere
Riverbed
River
Watercourse
Delta
Estuary
Waterfall
Challenges and Prospects
• Further development of geoportals faces a number of challenges:
• Protecting copyright
 Digital resource owners share a common concern over protecting
copyright
 Once the data is given to a user, the owner pretty much loses control
of data
 They hope for effective ways to ensure their data is only used by
authorised users, only for a period authorised and only for certain
types of apps.
 Solutions:
 DRM (digital rights managements) related mechanism.
 ISO – GeoDRM reference model, specify payment based on
information sharing and data lock mechanisms – illegally or after the
expiration date
Challenges and Prospects
•
•


Further development of geoportals faces a number of challenges:
Protecting copyright
Solutions:
Integrating data copyright protection specification within the
information sharing workflow of geoportal remains a challenge
Challenges and Prospects
No protection
Copyright
statement
Click-through
license
Managed
access
Watermarking
Digital intellectual property can be managed and protected in
numerous ways
Encryption
Challenges and Prospects
•
•



Further development of geoportals faces a number of challenges:
Data mining
Authoritative data is extremely valuable
Massive amount of GI contributed by casual web users – valuable
Such data unstructured, dynamic, lacking of quality authoritative
data
 How to extract information from the massive web, then verify its
authenticity, determine its spatial and temporal accuracy, and
incorporate it into geoportal – a demand research attention
Conclusion
• The more information that is available, the harder it is to
locate a particular piece of it, and the stronger the need for
geosportal
• The formats used to share geospatial information also have
advanced and diversified - web services, KML, GeoRSS, Online
data, offline data, others
• Geoportal should effectively facilitate the discovery and use of
web services
• Semantic Web, the next generation of the Web – the meaning
(semantic) of information is defined, making it possible for
machine to process it. While the full realisation is still a long
way off, the implementation is expected to reduce the
vagueness, uncertainty, and inconsistency of natural language
– making discovery of GI more intelligent and accurate
Conclusion
• The sharing of information is not only a technical issue, but a
social issue as well.
• Information is power. Sharing information with the right
parties multiplies the power
• Restrict the sharing due to national security concerns
• Technological advances in GPS, - civilian GPS unit on the
market can reach 10m accuracy- sufficient to produce 1:5000
scale map - + Google Map, Bing Map provide submeter
resolution imagery for many region – limiting public access to
such similar data has little meaning in terms of national
security – but rather serves to limit the app of GIS to serve
society
• Not motivated due to the fear to lose control over the data
Conclusion
• Not motivated due to the fear to lose control over the data
• The role of government to promote the sharing through policy,
law and regulation
• US freedom of Information Act 1966 – President Johnson –
federal govt agencies are duty to bound to provide
government records and data, including geospatial data to the
public free of charge or at minimum cost , if the data does not
invade personal privacy or national security.
• More than 100 countries have developed similar legislation or
policies that endorse SDI.
• How about Malaysia?