Transcript (Geo)-Interoperability Experiments – perspectives from UK

6th October 2005
JISC (Geo)-Interoperability Project
GWG 06092005
James Reid
GeoServices, EDINA
1
Overview

Background and rationale
o
o
o
o
Who?
What?
Why?
How?
Demo
 Issues
 Conclusions
 Recommendations and discussion

2
Who ?
(as unfunded partner and data provider)
3
What is ‘Interoperability’ ?
“The ability of software and hardware on multiple machines from
multiple vendors to communicate. “
(The Free On-line Dictionary of Computing)
“The ability of a system or a product to work with other systems or
products without special effort on the part of the customer.”
(whatis.com)

Products achieve interoperability with other products using either or both of
two approaches:


By adhering to published interface standards
By making use of a "broker" of services that can convert one product's interface
into another product's interface "on the fly"

A good example of the first approach is the set of standards that have been
developed for the World Wide Web. These standards include TCP/IP,
Hypertext Transfer Protocol, and HTML.

The second kind of interoperability approach is exemplified by the Common
Object Request Broker Architecture (CORBA) and its Object Request Broker
(ORB).

In the world of (geo)-interoperability, the favoured approach has
been to move towards adopting interface standards.
4
Remote access via web services
University College,
London
Demis,
Netherlands
Globe,
Colorado
MIMAS,
Manchester
GeoData
GeoData
GeoData
EDINA,
Edinburgh
GeoData
Web Services
Web Services
Web Services
Web Services
GeoData
IONIC,
Belgium
Web Services
GeoData
Web Services
Metadata
Maps
Data
5
Interoperability and the JISC IE

JISC 5 year strategy:
“an on-line information environment providing
secure and convenient access to a
comprehensive collection of scholarly and
educational material”

It is recognised that interoperability is of
fundamental importance and that the JISC IE
is a component of the national and global
networked environment
6
Interoperability and the JISC IE

To date, there has been no formal geospatial
interoperability study between the national data
centres, or between the national data centres and
users in institutions. This work is required as:


there is a need to understand how the UK academic
sector can best exploit developments in the standards
underpinning these developments.

greater understanding is required of what is involved in
supporting research and education in this important area
in the future.
Hence this project….
7
Why ‘Interoperability’?







Increases the value of existing and future
investments in Information Systems.
Allows portability of data.
Expands choices for vendor alternatives – no
vendor lock-in.
Enables vertical industry segments to unify
trading practices.
Decreases the long-term cost of ownership
for applicable software investments.
Enables leverage of existing skill-sets, i.e.,
does not require proprietary training.
Provides a benchmark for software design.
8
Why? - A view from the bunker…
"I'd like to see an [OS maps] API to rival Google, … that the API will
be published as an open standard and so not subject to arbitrary
change, and that it will be made available to all.
Open standards may evolve more slowly but they are reliable and
can't be changed simply because the commercial priorities of their
owners have shifted.
These open interfaces are the key to the next stage of the internet's
evolution, just as they have been the driving force behind its
development to date.
It doesn't matter whether the program at the other end is a simple
terminal emulator or the interface to a massively sophisticated
mapping system - once the interface is published it can be used. “
Bill Thompson, Technical Analyst
http://news.bbc.co.uk/1/hi/technology/4640893.stm
9
How - OGC Specifications (some!!)
 Web Map Service (WMS)

Specifies the behavior of services that return
georeferenced maps
 Web Feature Service (WFS)

Interface that supports query level access to
vector data repositories
 Web Coverage Service (WCS)

Supports networked interchange of geospatial
data as ‘coverages’ containing values or properties
of geographic locations
10
How – In more Detail…
Lets look at the most
popular standard –
WMS - in more detail…
11
How - Web Map Server Specification 1.1.1
Specification defines syntax for URLs to invoke
map operations. XML encoding defined for service
level metadata.

GetCapabilities


GetMap


Returns server-level metadata, description of services
and content, acceptable request parameters
Returns map image whose geospatial and dimensional
parameters are well-defined
GetFeatureInfo

Returns information about particular features shown on
map (optional)
12
How - WMS Interface: Operation
GetCapabilities
Web
Map
Service
Capabilities XML
Document with
Layer Information
GetMap
Client
Rendered Map Image
GetFeatureInfo
Returns info about
feature
Legend
Roads
Water
Buildings
Map Layers
Adapted from Web Map Server Demonstration presentation
© 2000 OGC
13
How – Images vs Data

Image Services
 Deliver image only (snapshot of the data), not
actual feature (vector) data
 More limited functionality—can’t export locally;
changing symbology more limited
 Lower bandwidth requirement

Feature (data) Services
 Streams actual feature data over the Internet,
available as individual feature classes
 Allows extra functionality of changing symbology or
exporting the data locally; cleaner maps
 Higher bandwidth requirement
 Filtering; more sophisticated linking
14
Back to the project!
Specific Project aims:

to prove the feasibility of delivering geo-spatial data
using OGC standards;

to demonstrate ease of use and added value;

to build support and enthusiasm for further development;

to stimulate and advance further thinking; and

to identify major hurdles in full development.
15
Project Outputs


A range of OGC based web services (WMS; WFS;
WCS)
A basic annotation web service (based on OGC XIMA
specification)


A series of demonstrator clients to illustrate:

Access to data (see demo)

A teaching focussed use case (urban expansion)

A research focussed use case (based on dynamic image
registration using web services)
A report on the utility and issues surrounding
implementation of open standards for geospatial
data within the JISC IE, including an assessment
of security and access authorisation issues
16
Demo…
Project website
17
Issues
• Security
• Scalability
• Technical implementation
• Metadata
18
Conclusions
• Use of open standards is:
– (relatively) easily achievable
– desirable (discuss!)
• A number of practical issues need to be
addressed before wider adoption
• There are both internal and external drivers
within JISC IIE that may push towards adoption
“A service-oriented framework provides significant benefits to stakeholders
including policy makers, managers, institutions, suppliers and developers and is
a business driven approach for developing ICT infrastructures that encourages
innovation by being agile and adaptive.”
(Statement of Principles, e-Framework Overview, July 2005)
19
Recommendations
[FOR DISCUSSION]

a further Interoperability Pilot in order to establish the basis of a Web Registry for UK
academia’s geospatial resources be conducted. The objectives of any potential follow
on project(s) should be to consolidate and further nurture the OGC services developed as
part of this project and to exploit (investigate?) these within a service oriented infrastructure
by embedding within other JISC services.

a specific working group (perhaps the Grid GIS Working Group) be tasked with
investigating web services security issues and that workshops (incorporating the
ongoing JISC funded work on Shibboleth) be convened in order to establish best practice
and to recommend a road map for addressing security and geoDRM aspects of
geospatial interoperability within the UK academic community.

investigations into the issue of service scalability and resilience via a funded
programme of stress testing and exploration of alternative service architectures (hardware
and software mixes) be undertaken in order to establish whether the e-Framework
service oriented approach is a sustainable approach for the delivery of geospatial
resources.

ongoing (financial) support to the existing Interoperability partners is made in order
to maintain and diversify the range of services they can support and make available
via interoperable means. JISC with the assistance of the JISC GWG needs to come up with
a strategy to take this forward with funding commitment for services from JISC.
20
21
A ‘traditional’
online service
A Web Services
based Service (ie OGC like)
Via a Repository (ies)
WAAS Client
WMS Service
?
WMS Service
Proprietary
Service
WAAS Service
WFS Service
GeoData
GeoData
GeoData
EDINA
National
Data
Centre
Research Council
Institute
Data
set
1
Data
set
2
National
Data
Centre