1. BADC, BODC, CCLRC, PML and SOC
NDG Status
Bryan Lawrence
(on behalf of a big team)
Introduce myself and Wendy and ask them to contact her. + + + + +[ ]=
BADC, BODC, CCLRC, PML and SOC

2. Outline Motivation Standards NDG Products NDG Timeline Feature Types
Overall Architecture (Taxonomy, Deployment)
Discovery Portal
Data Extractor
MOLES
(Security, NumSim)
CSML
Description
Prototyping in MarineXML
Round-Tripping
NDG Timeline

3. Complexity + Volume + Remote Access = Grid Challenge
British Atmospheric Data Centre
NCAR
British Oceanographic Data Centre

4. Integration – semantics
Want interdisciplinary semantic access to information, not abstract data
getData(potential temperature from ERA-40 dataset in North Atlantic from 1990 to 2000)
not: getData(“era40.nc”, ‘PTMP’, 20:50, 300:340, 190:200)
or even worse:
for j=1990:2000
getData(“era40_”+j+“.nc”, ‘PTMP’, 20:50, 300:340)
Lossy is OK!
Care less about completeness of representation than semantic unification
What we really want is access to *semantic information*, not files.
For the previous example, we’d like to be able to make a semantic query – e.g. all the temperature data in the North Atlantic between 1990 and Instead, typically we have to make some messy loops and know file names, file formats, and internal structures.
For the present, we’re more interested in providing a semantic view of the *core information* than preserving every single piece of associated metadata inside the file.

5. Integration – Access Control
Want decentralised access to resources, implies:
Data lies in
Multiple Locations
Protected by different “user databases” (/etc/passwd, whatever)
Differing standards for access control (from none, to restricted to license holders)
No overall agreement on access control “roles”!
No central user database
Needs to be scalable.
When NDG started there was NO grid based paradigm that met these requirements.
Now Shibboleth and/or Permis meet some of these requirements, but we have designed and prototyped a unique implementation of a new security infrastructure.
What we really want is access to *semantic information*, not files.
For the previous example, we’d like to be able to make a semantic query – e.g. all the temperature data in the North Atlantic between 1990 and Instead, typically we have to make some messy loops and know file names, file formats, and internal structures.
For the present, we’re more interested in providing a semantic view of the *core information* than preserving every single piece of associated metadata inside the file.

6. Standards ISO 19101: Geographic information – Reference model
…in a defined logical structure…
…delivered through services…
…and described by metadata.
A geospatial dataset…
…consists of features and related objects…

7. Standards Geographic ‘features’ Application schema
“abstraction of real world phenomena” [ISO 19101]
Type or instance
Encapsulate important semantics in universe of discourse
“Something you can name”
Application schema
Defines semantic content and logical structure
ISO standards provide toolkit:
spatial/temporal referencing
geometry (1-, 2-, 3-D)
topology
dictionaries (phenomena, units, etc.)
GML – canonical encoding
[from ISO “Geographic information – Rules for Application Schema”]

8. Standards ISO standards
TC211 – around 40 standards for geographic information
Cover activity spectrum: discovery  access  use
Provide a framework for data integration
Feature types
ISO 19103
Universe of discourse
Application schema
ISO 19109
ISO 19110

9. Architecture: NDG Metadata Taxonomy
CSML
NCML+CF
MOLES THREDDS
CLADDIER
DIF -> ISO19115
… not one schema, not one solution!

10. Architecture:
Deployment

11. Discovery Service http://ndg.nerc.ac.uk/discovery
NDG Products: Discovery Portal
NB: Web Service Interface (you can do the search from your own site and format and present the results there!

12. Can order responses by Title, Data Centre or Temporal coverage (default random)
Choose to return either data or “B-”Metadata
Look at DIFs in either HTML or XML

16. NDG Products: MOLES
Ugly as sin! A hint of things to come:
Detailed Browse Service is currently in development.

17. MOLES: implementation
Core linking concept is the deployment
of a Data Production Tool
at an Observation Station
on behalf of an Activity
that produces a Data Entity
Activity
Data Production Tool
Observation Station
Links the metadata records into a structure that can be turned into a navigable structure
Deployment
Each of the main metadata objects has security data attached to it. This means that this can be applied to queries on the metadata
Use of Xquery
Each record has its own security metadata attached, thus giving a degree of granularity to the security.
Data Entity

18. Simulators as data production tools: NumSim
NDG Products: NumSim

20. Attribute Certificate AttributeAuthority WS
NDG Security
Client Application
UserSession
CredWallet
SessionManager WS
Attribute Certificate
Proxy Cert.
Authorisation Request
User Roles
AttributeAuthority WS
Role Map
Gatekeeper WS
Attribute Certificate + data URI
Access Decision
User Database
User ID
CredWallet Stores any Attribute Certificate acquired
Assumption – user is known to the AttributeAuthority so no role mapping is necessary
NDG Products: NDG Security

21. NDG Products: DataExtractor

24. NDG Products: GEOSPLAT
Background activity being parallelised with GODIVA/CCLRC e-science collaboration (spectral -> gridpoint + CDMS + visualisation tools)
NDG Products: GEOSPLAT
Download either plot or the data that went into the plot.

25. ERA40:
All driven from one CDML file, 9 TB online spherical harmonics, looking like 40 TB “virtual” gridded!

26. NDG-A: Climate Science Modelling Language
Aims:
provide semantic integration mechanism for NDG data
explore new standards-based interoperability framework
emphasise content, not container
Design principles:
offload semantics onto parameter type (‘phenomenon’, observable, measurand)
e.g. wind-profiler, balloon temperature sounding
offload semantics onto CRS
e.g. scanning radar, sounding radar
‘sensible plotting’ as discriminant
‘in-principle’ unsupervised portrayal
explicitly aim for small number of weakly-typed features (in accordance with governance principle and NDG remit)

27. Climate Science Modelling Language
CSML feature types
defined on basis of geometric and topologic structure
CSML feature type
Description
Examples
TrajectoryFeature
Discrete path in time and space of a platform or instrument.
ship’s cruise track, aircraft’s flight path
PointFeature
Single point measurement.
raingauge measurement
ProfileFeature
Single ‘profile’ of some parameter along a directed line in space.
wind sounding, XBT, CTD, radiosonde
GridFeature
Single time-snapshot of a gridded field.
gridded analysis field
PointSeriesFeature
Series of single datum measurements.
tidegauge, rainfall timeseries
ProfileSeriesFeature
Series of profile-type measurements.
vertical or scanning radar, shipborne ADCP, thermistor chain timeseries
GridSeriesFeature
Timeseries of gridded parameter fields.
numerical weather prediction model, ocean general circulation model

28. Climate Science Modelling Language
ProfileSeriesFeature
CSML feature types
examples...
ProfileFeature
GridFeature

29. MarineXML Testbed XML XML XSLT XML XSLT XSLT XML XSLT XML XSLT XSLT
For each XSD (for the source data) there is an XSLT to translate the data to the Feature Types (FT) defined by CSML. The FT’s and XSLT are maintained in a ‘MarineXML registry’
Data from different parts of the marine community conforming to a variety of schema (XSD)
Phenomena in the XSD must have an associated portrayal
XSD
The FTs can then be translated to equivalent FTs for display in the ECDIS system
XML
Biological Species
S52 Portrayal Library
XSD
XML
Chl-a from Satellite
XML Parser
Marine GML (NDG) Feature Types
XSLT
XML
XSLT
XSLT
SENC
SeeMyDENC
Measured Hydrodynamics
XSD
XSLT
XML
XML
XSLT
XSLT
XSD
ECDIS acts as an example client for the data.
XML
Data Dictionary
Modelled Hydrodynamics
The result of the translation is an encoding that contains the marine data in weakly typed (i.e. generic) Features
XSD
Feature described using S-57v3.1Application Schema can be imported and are equivalent to the same features in CSML’
Features in the source XSD must be present in the data dictionary.
XML
S-57v3 GML
Slide adapted from Kieran Millard (AUKEGGS, 2005)

30. MarineXML Testbed
Biological sampling station with attributes for the species sampled at each
Grid of Chl-a from the MERIS instrument on ENVISAT
Predicted and measured wave climate timeseries (height, direction and period)
Vectors of currents from instruments
Slide adapted from Kieran Millard (AUKEGGS, 2005)

31. The Concept of re-using Features
Here structured XML is converted to plain ascii text in the form required for a numerical model
HTML warning service pages are generated ‘on the fly’
Here the same XML is converted to the SENC format used in a proprietary tool for viewing electronic navigation charts.
XML can also be converted to SVG to display data graphically
All this requires agreement on standards
Slide adapted from Kieran Millard (AUKEGGS, 2005)

32. CSML Round Tripping - 1 Managing semantics Conforms to UGAS produces
conceptual model
Conforms to
Managing semantics
101010
New Dataset
Application
produces
UGAS
GML app schema
XML
<gml:featureMember>
<NDGPointFeature gml:id="ICES_100">
<NDGPointDomain>
<domainReference>
<NDGPosition srsName="urn:EPSG:geographicCRS:4979" axisLabels="Lat Long" uomLabels="degree degree">
<location> </location>
</NDGPosition>
</domainReference>
</NDGPointDomain>
<gml:rangeSet>
<gml:DataBlock>
<gml:rangeParameters>
<gml:CompositeValue>
<gml:valueComponents>
<gml:measure uom="#tn"/>
<gml:measure uom="#amount"/>
<gml:measure uom="#gsm"/>
</gml:valueComponents>
</gml:CompositeValue>
</gml:rangeParameters>
<gml:tupleList>
GML dataset
instance
parser
V1.0 will be in NDG Alpha

33. CSML Round Tripping - 2 CF
Managing data - 1
<gml:featureMember>
<NDGPointFeature gml:id="ICES_100">
<NDGPointDomain>
<domainReference>
<NDGPosition srsName="urn:EPSG:geographicCRS:4979" axisLabels="Lat Long" uomLabels="degree degree">
<location> </location>
</NDGPosition>
</domainReference>
</NDGPointDomain>
<gml:rangeSet>
<gml:DataBlock>
<gml:rangeParameters>
<gml:CompositeValue>
<gml:valueComponents>
<gml:measure uom="#tn"/>
<gml:measure uom="#amount"/>
<gml:measure uom="#gsm"/>
</gml:valueComponents>
</gml:CompositeValue>
</gml:rangeParameters>
<gml:tupleList>
GML dataset
scanner
V1.0 in NDG Alpha
GML app schema
XML
instance
101010
CF Dataset
Application
produces CF
parser
V1.0 in NDG Alpha

34. Managing Data 2 PUBLISH scanner Define Dataset XSLT DECISION PROCESSES
<gml:featureMember>
<NDGPointFeature gml:id="ICES_100">
<NDGPointDomain>
<domainReference>
<NDGPosition srsName="urn:EPSG:geographicCRS:4979" axisLabels="Lat Long" uomLabels="degree degree">
<location> </location>
</NDGPosition>
</domainReference>
</NDGPointDomain>
<gml:rangeSet>
<gml:DataBlock>
<gml:rangeParameters>
<gml:CompositeValue>
<gml:valueComponents>
<gml:measure uom="#tn"/>
<gml:measure uom="#amount"/>
<gml:measure uom="#gsm"/>
</gml:valueComponents>
</gml:CompositeValue>
</gml:rangeParameters>
<gml:tupleList>
GML dataset
101010
CF Dataset
scanner
DECISION
PROCESSES
101010
CF Dataset
Define Dataset
Add Information
XSLT
XML
PUBLISH
ISO19115

35. NDG Timeline NDG2 runs until September 2007: NDG-Alpha (June 2006)
Not all components in place (particularly delivery broker)
Not many (maybe only DX) products will be deployable by non-NDG participants
(too much hard work installing things that haven’t been optimised for installation)
Discovery portal will be (is now) usable, linking to NCAR data etc, but isn’t very user friendly (options not obvious etc).
NDG-Beta (Feb 2007)
Most components should work, but deployment of software may still be difficult by non-participants
NDG-Prod (Jun 2007)
Should be deployable and far more user friendly (spending from Feb-June working on deployment and friendliness, no new functionality)
Last few months working on sustainability etc