Transcript Using Color Schemes
The GLOWA Volta Geoportal
an interactive geodata repository and information system
Dr. Serge Shumilov, Joscha Laubach Department of Computer Science III Antonio Rogmann, Peter Wittkötter Center for Development Research (ZEF)
University of Bonn
What is Geoportal?
Geoportal is a Web-based information system providing:
Easy interactive remote access to the GLOWA Volta data service
Cataloguing and management of heterogeneous datasets Internet
Web Browser
Web server HTTP
WMS Client
JDBC Data server Data catalog
Services to publish, access and share data over the internet
Tools for interactive search, visualization and analysis of data Intranet Geoportal HTTP SMB / NFS SMB Data storage
WMS Client Web Browser ESRI ArcGIS Client
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What Services does the GeoPortal provide?
Based on internationally approved standards the GeoPortal provides a variety of services: Catalogue Services
• •
Searching Browsing
and
filtering
of available datasets on the attribute level through a comprehensive data catalog and thematic maps
Portrayal Services Portal Services
•
Interactive mapping
• Tools for services for cartographic representation of spatially referenced data
visual exploration
and
analysis
of data • •
Download
of selected data (metadata)
Interactive means
for creating, upload and managing of data (metadata) resources
Administrative Services
• •
Users administration and security facilities Meetings planer
and
notifications
to enable communication and exchange of geoscientific information within defined groups
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Main Characteristics of the Geoportal Architecture
Expandable set of exchangeable active components (Java/JSP) for visualization, downloading and management of data ISO-compatible data catalog based on the Dublin Core metadata standard ensures compatibility with other catalogs Portal interfaces based on the specifications issued by the Open Geospatial Consortium (OGC) ensure that the portal and the data catalog can communicate with other catalogs and clients Virtualization of the web server improves portability of the Geoportal and significantly simplifies its installation The use of open source software based ensures cost-efficiency ESRI Arc Engine is a sole commercial software needed to access ESRI databases
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Component-based Geoportal Architecture
Geoportal architecture consists of several components providing particular portal's functionalities.
Data server (Linux) Virtual Machine (VMware) Web server (Windows) Apache Web server / Tomcat Geoportal DataManagers Search JSP/Java Viewers MapViewer GoogleMapViewer DataManager MetadataManager DataViewer Organizer UserManager ContentManager Downloaders DataDownloader MapDownloader JDBC / SMB NFS Geoportal DB Data catalog Data storage File system ESRI DB ESRI DB … ESRI ArcGIS Engine Runtime ESRI DB Antonio Rogmann / Serge Shumilov
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The GLOWA Volta Geoportal
compose, view and analyze on map download from map
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index and administrate assign use rights upload for distribution
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User and Operations in the Geoportal
The range of operations provided by the Geoportal is determined by the assignment of the user to a functional group
The goal is to warrant a coordinated web-based access for indexing, up- and downloading of data and management of the system ... ... with focus on the protection of owner rights of the resources hosted by the Geoportal!!
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User and Operations in the Geoportal
„Consumer“ – Level
Guest
► ►
(registered as “all” in the user database) search in meta data catalog visualize map based geodata with Map Viewer
► ►
download data in public domain don’t need to be registered personally in the Geoportal
Member of a specified user group (e.g. an institutional group)
►
same operation as the “guest”-user
►
download of data with access rights only for his user group
►
needs to have an user account in the Geoportal
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User and Operations in the Geoportal
„Contributor“ – Level
Meta Data-Uploader
►
enter, delete and upgrade of your own meta data sets
►
determine which user groups are allowed to access their data indexed in the catalog
„Administrator“ – Level
Meta Data-Administrator
►
control, edit, delete and approve of all meta data sets
Geoportal-Administrator
►
administrate user database and content of Geoportal Antonio Rogmann / Serge Shumilov
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Meta Data in the Catalogue-System
The data are indexed in a catalogue consisting of a range of meta data elements
This meta data elements provide detailed information, usable to assess if the resources are applicable for the own requirements of data processing and information
The GLOWA Volta Geoportal offers several ways to find data and other resources (documents, maps, applications) in the GLOWA Volta datastock by using the catalogue service ...
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Search for Data and Documents
Approaches to find data and documents by „search in meta data“
Keyword-based search in all catalog elements. Filtering by „AND“ search relation Selection for geodata embedded in Web Map Services only Search in predefined subject / topic list Antonio Rogmann / Serge Shumilov
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Search for Data and Documents
Approaches to find data and documents by „advanced search ...“
Combination of different criteria frequently used Advanced search to find data by criteria based on selected catalog elements Antonio Rogmann / Serge Shumilov
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Search for Data and Documents
More approaches to find data, documents (and maps)
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Search Results in Data Viewer
Short List Detailed Description Meta data sets which seem to be interesting can be reviewed in a detailed description within the data viewer Basic information needed to assess the data in relation to its usability is provided in the long version of the meta data set Scroll through a result shortlist Antonio Rogmann / Serge Shumilov
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Search Data by Relations in Meta Data Set
Topical relationships between resources (raw-data
can be browsed through meta data sets processed data)
Uniform Resource Name (identifier) acts as link to related data set Meta data set can be downloaded as text file Antonio Rogmann / Serge Shumilov
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Data Download
By obtaining the proper access rights, data can be downloaded directly from the catalog search result
Delivered as compressed file (.zip) Download button Permanent link can be copied and used e.g. in favourite lists
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Protection against unallowed Download
The major part of data in the GLOWA Volta datastock is protected by owner rights
To access protected data, the user has to have an user account in the Geoportal
The data of interest needs to be assigned in the meta data set to the user-group of which the user is a member
To get a membership, the Geoportal administrator has to be contacted by the user (by email)
Administration tool to generate user accounts and ...
... for user group management Antonio Rogmann / Serge Shumilov
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Visualization of Geo-Scientific Data on Interactive Maps
Geo-scientific data are stored in different formats with different behavior in the Geoportal
Single raster and vector files Relational geodatabases Map Projects (mainly ESRI ArcView and ArcGIS format)
Meta data editor with elements to describe Web Map Services geo-data properties
Web Map Service (WMS) displays spatial data
in its cartographic context interactively by providing fundamental GIS functionalities as raster images separated from the (protected) original geo data using a common internet browser
WMS: specified by the Open Geospatial Consortium (OGC)
supported by a broad range of GIS-clients (ArcGIS, GRASS, Open Jump, ...) interoperable with other, distributed Open GIS-services: WMS, Web Feature Service (WFS), Web Coverage Service (WCS), ....
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Types of Interactive Maps
The Geoportal provides two kinds of interactive maps as Web Map Services
Single WMS layers
searchable in the catalog and to be combined in one map viewer interface by the map basket
mainly used to
►
assess geodata in order to download and process locally
►
analyze spatial relationships for decision support One thematic layer (popu lation) and one basic layer (basin border)
Population Density 2000 in theVolta Basin
Project maps
composed of several layers with specific symbolization
mainly aimed to inform about GLOWA Volta Project research Several the matic layers in specific scientific context
Volta Basin Water Allocation System (VB-WAS)
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Access Interactive Maps with Map Basket
The Map Basket is a service to combine several WMS in one Map Viewer interface
Search only WMS Add WMS of interest to the map basket Result List Selectable layers for download. If required, together with the map project file (.mxd) Direct download is yet possible Antonio Rogmann / Serge Shumilov Content of map basket
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Organize the Map with Map Viewer
The map viewer is a cartographic interface in a web-browser
Manipulation of layer visibility and display range on map Legend corresponds with visible layers WMS link to copy for using the WMS in another WMS client like ArcGIS Three WMS Antonio Rogmann / Serge Shumilov
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Gain Information with Map Viewer
Example: NDVI is composed with climate stations (linked with rainfall time series)
Info button activation followed by mouse-click on map-object provides object related information Additional information: link to meta data set in order to get detailed information about the station Compare 1. WMS: mean annual NDVI with 2. WMS: mean yearly rainfall Additional information: Further available climate parameters collected by climate station Antonio Rogmann / Serge Shumilov
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Download Data with Map Viewer
WMS only displays interactive images of maps. Usable data are to be downloaded – if allowed for the user
Layer of interest can be selected Antonio Rogmann / Serge Shumilov
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Contribution of Meta Information to the Geoportal
Data about data (meta data set = catalog entry) describes data and resources - independently of the data storage location
Web-Services (e.g. for data download) offered by other institutions can be linked within a meta data set
Lacking web based facilities for data distribution: “contact” information leads on the way to get data
Offline (in the field) created catalog entries can be uploaded Meta data uploader gets the meta data upload tool Delete and edit own catalog entries Add new catalog entry Antonio Rogmann / Serge Shumilov
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Edit Meta Data with Meta Data Interface
Uniform Resource Name Generator (URN) gives each dataset described in the catalogue an unique identifier
URN syntax reflects properties of the described resource Uniform Resource Name is automatically generated
Unique identifiers avoid redundancies and confusion in the datastock
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Edit Meta Data with Meta Data Interface
The Editor provides an easy to use interface with about 25 element fields
Fill in of all elements is not mandatory
Range of elements can be extended flexibly if needed
Quality of entries controlled by Meta Data Administrator
Assignement of users or user-groups allowed to gather the dataset. Only needed if dataset is stored in the Geoportal data bases ready for download Antonio Rogmann / Serge Shumilov
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Integration of Data into the Geoportal
Data indexed in the Geoportal Catalog can be located
outside or inside of the central database hosted by GLOWA Volta (or another hosting institution) Advantage to store distributive data on the central data server: use of Geoportal Services to share data via web
Integration of own datasets into the central database needs …
… a registration to get the necessary meta data upload and administration rights (contact the Geoportal administrator)
… the consideration of certain standards in regard to the preparing of data which is going to be shared Antonio Rogmann / Serge Shumilov
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Data Management Standards
Standards in data quality (control), naming conventions and exchange formats improve the use and processing of data
To inform about the level of data quality just gives the data quality!
Meta data element Quality control
Significant file naming simplifies the organization of data files (e.g. after download on the local machine)
glowa_hyd_discharge_arli-dou-burkinafaso_1978-1987_monthly.csv
Project Scientific discipline and topic Antonio Rogmann / Serge Shumilov Spatial coverage Time frame
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Data Management Standards
GLOWA Volta Data Management Workflow describes steps in data handling and transfer
Step 2: identify the data by assigning an URN and/or name Data management step icons are linked with explaining documents
Workflow will be published as web page close to the Geoportal!
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Integration of Data into the Geoportal
Upload of data sets, documents and other resources to the central database
Server Area Local Area Data upload as next step after meta data upload This was shown before Antonio Rogmann / Serge Shumilov
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Integration of Data into the Geoportal Infrastructure
Data transfer at the Center for Development Research (ZEF)
Integration Distribution
Coordinated data integration and distribution
Administrator controlls integration
ZEF-Inhouse Local Data ZEF Member Extern External User Registration and login data transmission Intranet Geoportal SSH
Only quality controlled data meeting the standards is transferred into the central data bases – ready for distribution
Antonio Rogmann / Serge Shumilov Shared Data Open Area ZEF-Data-Server Meta DB Secure Area Central Uploaded Administrator Data base Data restores new uploaded data Transfer Area Admin
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