nationaal lucht- en ruimtevaartlaboratorium national aerospace laboratory nlr cxxx-1a edwin wisse...
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Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-1A
Edwin Wisse & Rob van SwolEdwin Wisse & Rob van Swol
National Aerospace LaboratoryNational Aerospace Laboratory
NeonetNeonetA metadata application demonstrating SatCASTA metadata application demonstrating SatCAST
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-2A
Overview
History: Sawa and SatCAST demonstrations
Neonet network
The software
Metadata gathering and distribution
Using multicast to distribute metadata
Demonstration
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-3A
1998: Sawa demonstration Demonstrated IP over satellite & caching, no multicast
Application: Neonet version 0
No XML yet: HTML based
Built a single site combining and crosslinking pages from different sites about a common theme: remote sensing
Site was replicated on different UNEP sites by retrieving databases with HTML files.
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-4A
2000: SatCAST demonstration Multicast capability
Demonstration application: Neonet version 2
Using structured metadata in XML
Network with nodes about different topics in remote sensing
Demonstration:– Neonet functionality– Database synchronisation by multicast over satellite link.
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-5A
Neonet: BackgroundNeonet: Background
Netherlands Earth Observation NetworkNetherlands Earth Observation Network
Allow (Dutch) users of remote sensing data access to Allow (Dutch) users of remote sensing data access to information in the Netherlands and abroad.information in the Netherlands and abroad.
Keep information at the providerKeep information at the provider
Connect to other metadata infrastructuresConnect to other metadata infrastructures– CEOS IDNCEOS IDN– CEOCEO
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National Aerospace Laboratory NLR
CXXX-6A
Neonet nodes
A Neonet node is a website with supporting software.
A node covers a self-chosen theme in remote sensing
Users can search for and enter metadata in a fixed format.
Format is derived from the CEOrecommendation on metadata.
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-7A
Neonet network (1)
The network is a group of nodes running Neonet software
Node maintainer(s) decide what is appropiate information
A node servers a user community, example:– atmospheric chemistry– water management
Nodes are organised hierarchically
General node at top: APEX
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National Aerospace Laboratory NLR
CXXX-8A
Neonet network (2)
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-9A
Metadata flow
NodeNode
Provider
metadata file
NodeNode
NodeNode
Metadata entered at a
specialised node is sent
automatically to the nodes
above.
E-mail is available everywhere
Even behind firewalls
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-10A
Neonet software
Retrieve metadata from provider by HTTPRetrieve metadata from provider by HTTP– Version 0: HTML pagesVersion 0: HTML pages– Version 1: metadata in XML pages (CEO like format)Version 1: metadata in XML pages (CEO like format)
Uses CEO standard for metadataUses CEO standard for metadata
Status: version 2 released october (but used in SatCAST) Status: version 2 released october (but used in SatCAST)
Available for interested institutesAvailable for interested institutes
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National Aerospace Laboratory NLR
CXXX-11A
Software: elements
• A Neonet node runs:• Webserver• Database• Servlet package• Java application for
database sync and metadata retrieval
• Nodes can be installed on systems running Windows and a number of Unix systems (SGI, Solaris, Linux).
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National Aerospace Laboratory NLR
CXXX-12A
SatCAST setupSatCAST setup
3 top level nodes with local databases and no sub-nodes
Synchronisation:– Nodes synchronise their databases using HTTP requests– Added for SatCAST
Multicast aspect:– New or changed XML files get broadcasted to all nodes– Nodes retrieves files and records from local cache– No multicast for servlet results, only for database
synchronisation
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-13A
Synchronisation
NodeNode
XMLadmin
NodeNode
XMLadmin
SatCAST
Multicast
NodeNodeA node exports its database to a
set of XML files, so it can be accessed
using HTTP
Nationaal Lucht- en Ruimtevaartlaboratorium
National Aerospace Laboratory NLR
CXXX-14A
Demonstration
Three nodes were set up, all are Apex nodes.
Check each other every 10 minutes.
Metadata entered at 1 node is found and retrieved by the others
No instant result
Short demonstration of other Neonet features
Questions?