Technical Description
Smart
Atlas was developed by the Coastal and Marine Research Centre (CMRC) as part of
UNESCO's International Oceanographic Data and Information Exchange (IODE) Ocean
Data and Information Network of Africa(ODINAFRICA) project. It is being
deployed and used by ODINAFRICA and SPINCAM partners.
Smart
Atlas is an 'atlas in a box' that is easy to deploy and customise. It allows
users to publish maps on the web in an easy way.
Smart Atlas relies on UMN MapServer's MapScript as a server side. It has a web
graphical user interface developed using GeoExt and ExtJS.
Smart Atlas is
a web GIS that allows access to, and visualisation of data and metadata. It can
be connected to an OGC catalogue service (CSW 2.0.2) that supports Dublin
Core [ISO03] and ISO-19139 metadata standards (e.g.GeoNetwork). It relies on
UMN MapServer to render maps.
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Mapping interface with common map controls (zoom,
pan, feature information, distance measuring, navigation to an area of
interest, print, etc.)
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A variety of base maps (ESRI maps, Google maps and
Open Street Map)
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Data browsing by a hierarchy of categories
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Simple and advanced data search
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Layer management (transparency, order, etc.)
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Layer information (summary/full metadata and
legends)
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Data download - if download links are
provided as part of metadata delivery information according to the GeoNetwork
protocol naming convention
Figure 1 Smart Atlas View Services. This example shows bathymetry of
Ireland's surveyed sea territory
An interface has been
implemented based on the latest AJAX frameworks and APIs, notably ExtJS and
GeoExt. The interface has been implemented as a rich Internet application (RIA)
with a fairly interactive and flexible layout. It has been designed in a
modular way that makes it flexible and easily customisable. Particular
attention was paid to cross platform browser compatibility. The mapping
interface (c.f., Figure 1) includes four areas:
1.Banner:
A customisable HTML banner for containing the atlas title, sub-title,
organisation, logos, personal menus, etc.
2.Layer Area:
a resizable, collapsible/expandable area that contains three views of layers
organised in different tabs:
1.[Base]
Built-in base layers, such as Google maps and Open Street maps
2.[Overlays]
Atlas layers
3.[Selected
Layers]: contains the list of active layers, sorted by depth, with possibility
of changing the layer order by simple drag and drop, and layer transparency
using a slider.
3.Map:
GeoExt-based map with support for WMS and common base maps (ESRI maps, Google
Maps, and Open Street Maps). The map supports dynamic tiling. A tile caching
mechanism allows quick map loading. In addition to the classical navigation
controls (zoom in-out, pan, full extent, feature information, etc.), the
mapping interface included tools for adding features, drawing, measuring,
printing, and previous and next in history. The map may be visualised in full
screen by collapsing the layer and information areas.
4.Information:
Information on a selected layer is displayed in this area. Access is also
provided to the Search Functionality via this area.
The server side code is developed in PHP and
requires MapServer's MapScript API. It extends MapScript's capabilities by
supporting hierarchical categories of layers and the customisation of feature
information display.
Smart
Atlas can be configured to connect to one or more catalogue services
implementing the OGC CSW 2.0.2 specification (e.g., GeoNetwork). This allows
users to search for datasets through metadata stored in catalogue services.
Smart
Atlas supports distributed CSW search. The search can be done through the
following search criteria as shown in Figure 2 :
Simple Search
Advanced Search
To carry out a simple
search user enters free text in the search box and clicks on the search
icon. Any relevant records found are returned in the window below.
Figure 2 Simple Search interface
Advanced search allows user to fill in a number of optional fields. These
are described in more detail here:
*
What: The user can specify
the title of the target metadata record, keywords and any text that might be
included in the metadata file. This is done through the 'What' panel in the
information tab - refer to Fig 3 below
Figure 3 'What' Tab in Advanced Search Panel
*
Where: User can select a
geographic extent for the searched metadata records. A map is provided where
the user can pan, zoom-in, zoom-out to the target area of interest and then
draw a bounding box around that area. Refer to Fig 4 below
Figure 4 'Where' Tab in Advanced Search Panel
Three visualization methods are now in place for metadata record results:
A simple metadata
record visualization which contains basic metadata fields like title, abstract
and subject of the record. Refer to Fig 5 below. Individual metadata records
are available with 'Download data' button to download the datasets associated
with a metadata record if available and 'View in map' button that can overlay
the dataset on the mapping area for visualization or further processing.
Figure 5
Summary Metadata Record
A full metadata
record which is rendered using external visualization/transformation scripts
for displaying the full metadata record. Refer to Fig 6 below:
Figure 6
Extract from a Full Metadata Record. A user can view the full record by
scrolling
The Metadata record
is viewed with simple FAQ style where basic questions/answers about the
metadata record are introduced. Refer to Fig 7 below:
Figure 7
Metadata Record FAQ
The atlas can be configured and customized
using a set of configuration files and style sheets (CSS) that are documented
in the installation manual (provided with Smart Atlas). You can customize the
look and feel, as well as the atlas parameters (bounding box, catalogue
services, datasets and categories, area of interest, etc.).
Smart Atlas
has the following known issues, which can be further addressed/improved:
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Smart Atlas currently supports Geonetwork 2.6 which is not up to date. upgrading to support Geonetwork 2.10 is recommended as it provides new functionality like multiple languages search, revised metadata record visualisation and optimized search
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Information tab functionality is basic at the moment and can be improved to include a wealth of data information about individual layers that can be set in an external spread sheet files
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Full metadata section and style sheets can be improved to extract these from Geonetwork metadata server
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A launch page template can be developed to be provided alongside the atlas to contain introductory information about national atlases
Online help (fig 9) is now integrated in the
atlas. Users can hit the help button to get an overview of the atlas and get
more information about specific functionality on the different areas and tools
that can be used through the atlas. A word document user manual is also
available that illustrates in detail the use of the atlas and the different
functionality and tools available. It also includes a FAQ section that include
a set of common questions and tasks that user may need to do using the atlas.
Figure
9 Smart Atlas online Help page
A download page (fig 8) is now available at http://smartatlas.ucc.ie/downloads
This page contains software packages of smart atlas
for Windows and Linux
Packages contain read-me files for
instructions on how to install the atlas and the Linux package contains a shell
script to install the atlas from a command line.
Figure 8
Smart Atlas software Download/Registration page