To address the complex connectedness of Earth phenomena, we need
to study interoperability as a discipline in its own right
Over the past 100 years the world’s
total population has quadrupled –
from 1.6 billion to 6.6 billion. (Footnote:
Population Bulletin, “World Population
Highlights: Key Findings From PRB’s
2007 World Population Data Sheet” http://
www.prb.org/Articles/2007/623WorldPop.aspx.
) In many parts of the world we see
growing poverty. We now face increasingly
worrisome resource constraints and
environmental difficulties, and many
informed observers question the planet’s
ability to sustain its current human
population, despite our technological
achievements. (Footnote: “Human Carrying
Capacity of Earth”, Gigi Richard, Institute
for Lifecycle Environmental Assessment,
ILEA Leaf, Winter, 2002 issue. http://www.ilea.org/leaf/richard2002.html)
Managing a “soft” leveling off of
population growth and resource
consumption will require, among other
things, that we make the best possible use of
information technologies, and particularly
geospatial technologies. Viewed separately,
these technologies are advancing rapidly
and are being utilized in a growing number
of ways. But harnessing them together to
meet the challenges of the 21st Century
will require a new kind of knowledge, new
policies, new institutional
commitments, and
imaginative reassessment
of our ways of using them. Figure 1: Information and communication technologies
relevant to the geosciences are all increasing in
capability and performance. costs are going down.
The Open Geospatial
Consortium, Inc. (OGC),
founded in 1994, has
established a global,
commercially driven
consensus process for
developing geoprocessing
interoperability standards.
The OGC Interoperability
Institute (OGCii), founded
in 2006 by OGC directors,
promotes research in the
area of “interoperability science,” to address 1) the need for new
knowledge related to the convergence of
geospatial technology with related enabling
technologies, a convergence enabled by
geospatial interoperability and 2) the
need for coordinated research community
input into the OGC standards process.
Surging need for interoperability
Individually, geospatial technologies
and related supporting information
technologies are advancing
rapidly, as shown in figure 1.
The problem we face does not concern
any inadequacy in the basic information
technology infrastructure for geospatial
interoperability. It is clear that we can
expect adequate progress in all the relevant
IT domains we identify as essential.
The problem is rather that we still have
difficulty using all the various kinds
of data and online processing services
available to support an integrated scientific
methodology. Our wealth of data and
the unifying power of interoperable
information technologies actually serves
to illuminate the traditional scientific and
institutional barriers to the construction
of the relevant complex models and
analysis which are needed to represent and
address many of today’s most complex
scientific and societal challenges.
Interoperability enables
resource sharing
Resolving humanity’s resource and
environmental difficulties requires that
we learn more about the often complex
relationships among a wide range of
Earth features and phenomena. To do
this, one thing scientists must be able to
do is find and use each other’s data and
services (online processing services) and
integrate these into complex models and analyses. Such sharing matters not only
for cross-disciplinary studies, but also
for longitudinal studies, independent
verification of results, and collaboration
on collection of expensive shared data
sets and development of shared Web
services. Such sharing is enabled to a large
degree by the OpenGIS® Implementation
Specifications developed by the OGC
in cooperation with other standards
organizations. These specifications
provide detailed engineering descriptions
of open interfaces, encodings and
online services that enable diverse
systems to operate together in a “loosely
coupled” client server environment.
To enable resource sharing, the first step is
to simply make data and services available
on the web through open interfaces. The
next step is to carefully describe the data
and services in machine-readable and
human-readable metadata that conform
to ISO standards. By means of this
metadata, the data and services can be
registered in online catalogs that make
them easily discovered, evaluated and
accessed. Fortunately, great progress has
been made in the area of metadata and
catalogue standards. Products are available
that make it relatively easy to develop
“application schemas” based on ISO
standard metadata schemas, and catalog
products are available that implement
the OGC’s OpenGIS Catalog Services
– Web Implementation Specification.
In many cases, these are sufficient to
make data, online services and encodings
easily discovered, evaluated and used by
humans and software using the Web.
Addressing complexity
We simply cannot avoid complexity
and the growth of complexity as we
contemplate and attempt interoperability.
We must accept the need for diverse
conceptual abstractions, classification
schemes, data models, processing
approaches and recording methods.
We must also accept the compounding
of complexity when multiple datasets
embodying this diversity are used together.
Standards are necessary in managing data
complexity, but they may not be sufficient.
Complexity is as dangerous as it is
unavoidable. Like physicists employing
mathematical theories in their attempts
to describe the cosmic and sub-atomic
worlds, geoscientists building computer
models of Earth phenomena depend
precariously on the accuracy of their data
and the validity of their assumptions. The
artifacts of modeling can, sometimes,
be mistaken for observations of reality.
Other tools like finite element analysis
and Fourier transformation that derive
much of their utility from computers
underwent rigorous community review
as they became common tools in the
science and engineering toolbox. We
unavoidably delve deeper into abstractions
as we explore complex relationships
between environmental factors, and
we need ways of determining whether
our inferences and conclusions are
valid. Consciousness about the need for
validation and the hazards of abstraction
compels us to study interoperability.
To address the complex connectedness
of Earth phenomena, we need to study
interoperability as a discipline in its own
right. We need to look for basic principles
and practices that can direct our efforts to
converge different application domains
and to converge geomatics with computer
modeling, semantics, high performance
computing and other technologies.
Consider, for example, climatology.
Knowledge about climate change is of
the utmost importance, and climatology
is a multidisciplinary field. Geospatial
data includes temporal and spatial
information about atmospheric gas and
particulate distributions and circulations,
terrestrial radiation and absorption
patterns, weather regimes, bolide impact
studies, plant distributions, industrial
plant distributions, and data developed
by hydrologists, paleoclimatologists,
sedimentologists, bathymetrists,
oceanographers, demographers and
others. Climatology is heavily dependent
on computer models, and the computer
models need to assimilate many of these
diverse kinds of data. Each kind of data
has peculiar characteristics and limitations.
In many cases, the limitations need to be
quantified in statistical parameters within
the models. Understanding geomatics
and geoprocessing interoperability in
the contexts of modeling, semantics,high performance computing and
other technologies is clearly of
great importance in this context.
Furthermore, getting and using Earth
science data involves other considerations
besides accuracy and validation. The
semantic facilities for interdisciplinary
sharing of diverse spatial resources, and
the digital rights facilities for such sharing,
for example, must smoothly transcent the
technical boundaries of Web resources
such as search tools, sensor webs, grid
computing, location services, etc. And all
of these must be harnessed in making huge
volumes of data and services accessible to
modeling and simulation tools. Together,
these challenges demand that we embark
on a concerted global effort to study the
interoperability-enabled convergence of
modeling, semantics, high performance
computing and other technologies that
together might support the fullest possible
use of geospatial data and services in
the rapidly evolving ICT environment.
OGCii
Commercially derived interoperability
requirements have been the main drivers
shaping the evolution in the OGC of
the global standards that are used by
both practitioners and researchers.
Commercially derived interoperability
requirements are a great boon to
researchers, but they may produce
standards that meet only a subset of the
interoperability requirements of studies
of complex Earth phenomena. Standards
developers must, by definition, seek
“common denominator” approaches,
approaches that are “as simple as
possible” for good practical reasons.
However, this goal frequently runs
counter to the need to have standards
that are “as complex as necessary” to
maintain rigor in scientific specialties.
The OGC Interoperability Institute seeks
to coalesce interest groups who have a
stake in these issues, with the intention
of focusing the research community’s
interoperability requirements for insertion
into the commercially driven standards
process and also focusing attention on the
need to make geospatial interoperability
the subject of concerted study.
David Schell Chairman and CEO of the
Open Geospatial Consortium,
Inc. (OGC) and OGCii, Inc.
Dr D R F Taylor Distinguished Research
Professor
Department of Geography
and Environmental
Studies,
Carleton
University, Ottawa, Canada
Member OGCii Board
