Transcript Georeferences

Madiera
Georeferences
- extending search for data
Ørnulf Risnes
www.nesstar.com
A Geo-referencing system
• Current problems with the DDI
– Difficult to use geographic references in a consistent
manner
– Difficult to use geographic references for something
useful
www.nesstar.com
What do we need?
• “We need a geographic identification of data
resources”
– Associate studies with geographic coordinates
• “A coordinate-aware interface that can support the
searching process”
– Search for studies using geographic coordinates
www.nesstar.com
Getting geographic coordinates
into studies
• Potentially large amounts of coordinate data
• Tagging process should be mostly automatic
• Fortunately,the DDI 2.0 has room for our coordinates!
<geogCover>Norway</geogCover>
<geoBndBox>
<westBL>4.789583</westBL>
<eastBL>33.637497</eastBL>
<southBL>57.987915</southBL>
<northBL>80.76416</northBL>
</geoBndBox>
www.nesstar.com
Geographic tagging using Nesstar
Publisher
• Nesstar Publisher can talk to a standard openGIS
map-server (WFS)
Publish dataset with
coordinates
Publisher
Nesstar Server
Select coordinates from
list of available maps
Web Feature
Server
www.nesstar.com
Geographic tagging using Nesstar
Publisher
• Publisher-user specifies map and subregions
Dataset/
DDI
www.nesstar.com
Geographic tagging using Nesstar
Publisher
• DDI with geographic coordinates is published to a
Nesstar-server
<codebook>…
<westBL>4.789583</westBL>
<eastBL>33.637497</eastBL>
<southBL>57.987915</southBL>
<northBL>80.76416</northBL>
Nesstar Server
…</codebook>
Now, the coordinates “live” on the server
and can be utilised in a search procedure
www.nesstar.com
Geographic searching in the
Madiera Portal
• The best way to select area of interest?
– Search for name of country or region?
– Using a map-interface?
It depends on the situation…
…but today we demonstrate a map-based
search interface
www.nesstar.com
Map-search requirements
The user must be able to:
• Select map from a list of relevant maps
• Zoom into an area of interest
• Submit the coordinates of the area of interest as a
parameter of a search query
• Allow for combination of area of interest and
additional parameters (i.e. text-based search)
www.nesstar.com
Map-search-interface
• …can be plugged into the Portal or any Nesstar
Server
• …talks to a standard openGIS map-server (WMS)
Map interface
Web Map
Server
Nesstar Server/
Madiera Portal
www.nesstar.com
Map-search-component
• …lets the user choose
maps from a list of
available maps
• …renders map
image from the
coordinates
www.nesstar.com
Map-search-component
• …supports zoom and pan
Demo: http://damad.essex.ac.uk/portal/index.html
www.nesstar.com