NERC Data Grid
Helen Snaith
What is NDG?
•
NDG provides the infrastructure
which allows users to
◦
Find data
◦
Explore what is known about datasets
(including information about the
observing or simulating tools)
NDG Services
•
The “NDG Discovery Service”
◦
A database of discovery information
◦
A web-site, to provide a portal to that database
◦
A set of web-services, allowing NDG consumers
to exploit that database
•
The “NDG Vocabulary Service”
◦
Databases of environmental thesauri and
ontology tools to map between terms
◦
Supports “machine assisted” browsing: eg,
search for
rainfall
and find datasets with
What Can NERC Data Grid
Do For You?
•
Depends on who you are!
◦
Data User - eg scientist looking for
data
◦
Data Provider - eg data centre, large
research group
◦
Developer - providing access tools or
As a Data User?
•
Discovery leads directly to data
◦
Simple search page or “google-like” toolbar
gives direct access to data, not just the
metadata
•
Comprehensive coverage
•
Seamless access
•
Hides data format differences and
provides generic visualisation tools
As a Data Provider?
•
Provides a standards based metadata
hierarchy
◦
Exploit the NDG metadata structures to design a
metadata system from the ground up, or use them
as an interoperability tool
•
No need to run multiple security systems
•
Increases visibility and usage of datasets
◦
Inclusion in NDG does not prevent inclusion in other
data discovery or access initiatives
•
Minimise user support load
As a Developer?
•
Exploit NDG web services
•
Exploit NDG modular
development
•
Exploit NDG metadata standards
•
NDG developments are
non-proprietary
•
NDG standards compliance
•
Discovery
◦
ISO standard
•
MOLES - Metadata Objects for
Links in Environmental Science
◦
Detailed metadata for browsing
•
CSML – Climate Science
Markup Language
What Can’t the NDG Do?
•
NDG can’t generate the metadata!
◦
Automated manipulation and searching relies on
comprehensive metadata, which require quality
data management to create and maintain
◦
NDG
does
provide a clear framework for
metadata requirements
•
NDG doesn’t provide information
services:- it provides data services!
◦
NDG
does
provide a framework within which it is
possible to link data to derived information
Competitors!
How is NDG different from the rest?
•
e2edm, End-to-End Data Management:
• Similar aims but using different technologies • NDG is more standards compliant
•
Thredds:
• Provides only catalogue services
• Thredds is significantly more mature than NDG
• Suitable for data providers with hierarchical data / metadata
•
OPeNDAP:
• A protocol for accessing data
• Limited support for access control
NDG Status
•
Approaching Beta
◦ Discovery Gateway◦ Discovery Service
◦ CSML V2
◦ MOLES
◦ Security Infrastructure
◦ Vocabulary Service
◦ MOLES browser
