Transcript IONIC Software Visit to ESRIN April 17, 2002

ESA Web Mapping Activities
Status Report
CEOS WGISS Subgroup
Chiang Mai - September 2003
C.Caspar
G.Tandurella
P.Goncalvez
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Recent upgrades since last
WGISS SG (Toulouse – May 2003)
– New Original Layers / Dedicated Servers
• MERIS Mosaic
• Landsat mosaic (as Project precursor)
• City Names
– New Developments
• POP (Oil Slick) last developments
• Client enhancements (new navigation, contexts, .)
• Aggregation of database features items (e.g. fire
atlas)
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New Original Layers …
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MERIS Mosaic
• Added in May 2003
• ENVISAT MERIS data, 1.2 km resolution generated by
GAEL Consultant (http://www.gael.fr/ ) for ESA from March
2003 data (5 bands out of 15)
• Volume of data 2.4 GB in a single file
• Potential Improvements: store each band as a separate
layer
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MERIS Mosaic
MERIS & ERS SAR - Chiang Mai
MERIS - Chiang Mai – March 2003
MERIS & LANDSAT- Chiang Mai
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LANDSAT mosaic
• Prototype implemented following presentation of
the LANDSAT project (Lorant & Wyn)
• LANDSAT-5 data samples on NASA server
(https://zulu.ssc.nasa.gov/mrsid/ ).
– Data compressed & projected in UTM. Pixel size: 28.5
m. Positional accuracy: 50 m.
• Transfer of a subset to ESA, decompresssion,
reprojection to Plate-Carrée and storage in raw
format on ESA WMS.
• 12 Files covering few test zones (France, Italy,
Irak and US East Coast). ~ 1.4 GB per file.
• Possible improvements: create lower resolution
files
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LANDSAT mosaic
Fires over the Etang de Berre (F)
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LANDSAT mosaic
Fires over Irak
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City Names - Limitations
• DEMIS City Server used regularly
(http://www.demis.nl/mapserver/mapper.asp )
• Several problems with DEMIS:
– single style (black color barely visible
over dark layers)
– overlay of city names (unreadable)
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City Names from DEMIS
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City Names - Alternative
• Import NIMA City DB file into ESA WFS
• Test made with French cities (~ 32,000 entries)
• Use IONIC new RedSpiderWeb™ server suite
(more efficient specification of rendering, style and string overlap)
• Still limitation due to the NIMA City DB content:
– Missing classification of cities according to city size.
– No possibility to filter the names according to the map
scale.
• Still seek for better city names DB / server ….
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Compared City
Names Servers
Layer from DEMIS
Layer from ESA WFS
(populated with NIMA data)
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New Developments …
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POP Project (Oil Spill Drift)
• Phase 1 demoed at Toulouse (QINETIQ &
ESA)
• Progress made since:
• Improve services interface using standard such as WSDL and
SOAP.
• Definition of interfaces and WSDL structures
• Service chaining: recursive service calls
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POP Current limitations
•
still GML 2
•
Many problems encountered in all components (client, WSDL, ..)
•
Client implementation targeted to the type of Web Browser:
E.g. Internet Explorer Client on Windows (use of Microsoft builtin SOAP support Webservice Behavior):
– Javascript to specify parameters (e.g. service provider description
WDSL, function of service provider, value)  automatic conversion to
SOAP message and submission to service provider
Netscape also offers an equivalent service (Mozilla SOAP API) but
not compatible with MS Webservice behavior
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POP Current limitations (cont’d)
• Client SOAP requests cannot be sent to remote Web
Servers (located in domains different from client’s) but sent
only to a single local Web server (ESA gateway – acts as
proxy to remote servers e.g. QINETIQ drift prediction
server)
© Microsoft
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POP Architecture
Static layer Combination
Metadata for a particular
Oil Slick
SOAP request:
Any GIS WMS server
Oil Slick Drift simulation
overlayed
ESA GATEWAY
Service + parameters
(value, services, ..)
Services Descriptions
(WSDL)
ESA Client
SOAP request
Any Oil Slick
Data Server
WMS, WFS
(later SOAP)
requests
Any
Meteo Server
SOAP answer:
URL (image), GML
WMS, WFS
(later SOAP)
answers
QINETIQ Drifting
Service
ESA Drifting Service
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POP lessons learned
• Use of WSDL and SOAP is not straightforward on
client side
• Client part badly documented:
– I.Explorer: built-in Web Services features, hide SOAP
complexity but only simple examples available.
– Netscape / Mozilla: SOAP library seems to better
documented but WSDL management not stable (crash)
• Difficulty to find examples of non-trivial
implementations
• Complex schemas not easily supported
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POP demo
Be patient
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Client Enhancements (1/2)
• Use of contexts (both pre-selected & user
defined).
– Flexible feature to show several distinct
thematic maps to users with single client. E.g.
ESA Web Map portal (under construction).
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Client Enhancements (1/)
• Use of contexts (both pre-selected & user
defined).
– Flexible feature to show several distinct
thematic maps to users with single client. E.g.
ESA Web Map portal.
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Client Enhancements (2/2)
• New layer navigation applet: more friendly,
better look & feel
• “Save as” function. Creates an HTML page
with a single PNG, GIF and JPG image
• Automatic Image resizing w.r.t. Web
browser window size.
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Layer Navigation Window
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Aggregation of database features
• Example of problem:
– 500,000 fires in ESA WFS. Too many fires
retrieved when time window is large (e.g. 30
seconds for a 1-month time window).
• Database feature to group “neighbouring”
data. On-the-fly aggregation by the DB
server. Less records to be extracted. E.g. 10
seconds for a 3-years time window.
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4 fires
Aggregation of
DB features
25 fires
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Current URL :
http://mapserv2.esrin.esa.it/
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