The Future of Digital Earth
Michael F. Goodchild
University of California
Santa Barbara
A digital globe timeline
Jan 1998: Gore speech on Digital Earth
April 1998: UCGIS Congressional Breakfast
Summer 1998: UCGIS meets in Park City
interest in developing a research program around
Digital Earth vision
Nov 1999: First International Symposium on
Digital Earth
Early 2005: Google releases Earth client
2005: Google Earth API, Microsoft Virtual
Earth, etc.
Client-server architectures
• Data volumes are massive
– 5 x 1014 elements at 1m resolution
• On-the-fly rendering in the client problematic
– refresh from the server problematic
• The Keyhole (Google Earth) solution
– precompute and pre-render a hierarchy of tiles on
the server in a standard DGG
– fetch tiles when needed
– warp tiles on the client to fit the current view
What made this possible?
• Abundant supplies of Earth data
– especially fine-resolution remote sensing
– the base layer
• Fast Internet access
• Fast graphics accelerators in PCs beginning
in 2000
• Published APIs enabling third-party
applications and data integration
Two versions of client functionality
1. Projected functions back-projected to the
sphere
–
inverting the projection equations
2. Doing the spherical (or ellipsoidal) geometry
–
–
–
no straight lines (only arcs of ellipses)
no lengths (only subtended arcs)
a new kind of computational geometry
Successes to date
• Speed
– video refresh rates via thin pipe
– powerful graphics universal
– browser or thin client
• 3D
– elevation relative to the ellipsoid
• User-centric
– mashups
– API-based apps
Significant gaps
• Models of the surface only
– not the solid Earth and atmosphere
• Lack of access to the grid
– no support for computational models that might
use the grid as a collection of finite elements
– but compare open-source alternatives such as
NASA’s Worldwind
• Lack of access to the base data
The Digital Earth
going to the library
drilling down
accessing information about a place
many media, one location
the geolibrary
the informed citizen at City Hall
the child at school
By the year 2005:
Possible to assemble all relevant
information from the resources of the
Internet
based on known location
Possible for a child to learn about Earth
and its infinite variety through the medium
of digital technology
from global to local
Status: Clarifying Digital Earth
• The 1998 Gore speech
– Earth in the Balance, 1992
– Neal Stephenson’s Snowcrash
• a mirror world
• Who is Digital Earth for?
– “a young child”
– someone needing geospatial data
• a researcher
• an educator or student
• a stakeholder
– a citizen interested in the planet and its future
– a developer
– “build it and they will come” (Field of Dreams)
• it seemed like a good idea at the time
What should Digital Earth do?
• The use cases of Digital Earth
– “a magic carpet ride”
– a method of publication
• mashups
– copy GIS
– more visual, intuitive, subjective
• search for anomalies, interesting patterns
• search for similarities
– a source of data
•
•
•
•
•
geoportal
interoperable
hidden tiling
intuitive interface
creative commons
Use cases (contd.)
• The reality of data access
– virtual globes do not allow data download
– downloadable data:
•
•
•
•
are not interoperable (syntax and semantics)
tiling is exposed
projections are exposed
no metadata
• Simulation of social and environmental
processes
– functions, rules that transform the system at time t
to the system at time t+1
Digital Earth as a simulation engine
• A platform for transforming the world
–
–
–
–
visualizing the Earth’s future
in an accessible package
a child-of-ten interface
what the Earth used to look like
• and what it will look like in the future
Broader success
• Engagement of the citizen
– child of 10 in 10 minutes
– citizen as producer and consumer (prosumer)
– neogeography
• A communication medium
– compare “GIS as media”
– presenting the results of global science
• to the citizen, not the shelves of a library
– the full life cycle of Earth data
– past, present, and future
Prospects: Where are we now?
• The digital globes implement only parts of the
Gore DE vision
– data access
• geoportals are not integrated
• limited syntactic, semantic interoperability
• limited accuracy
– future scenarios
• simulations
• how the world looks today
• limited perspectives on the past
The Vespucci research agenda
• Developed at a specialist meeting in
Florence, Italy, in 2008
• M. Craglia, M.F. Goodchild, A. Annoni, G. Camara,
M. Gould, W. Kuhn, D.M. Mark, I. Masser, D.J.
Maguire, S. Liang, E. Parsons (2008) Nextgeneration Digital Earth. A position paper from the
Vespucci Initiative for the Advancement of
Geographic Information Science. International
Journal of Spatial Data Infrastructure Research 3:
146–167.
The Vespucci specialist meeting
• Florence, June 2008
• Re-visioning Digital Earth
– the next generation
• Participants:
Max Craglia, European Commission Joint Research Centre
Mike Goodchild, University of California, Santa Barbara
Alessandro Annoni, European Commission Joint Research Centre
Gilberto Camara, National Institute for Space Research, Brazil
Mike Gould, University Jaume I, Castellon, Spain
Werner Kuhn, University of Münster, Germany
David Mark, State University of New York at Buffalo
Ian Masser, University College London
David Maguire, ESRI, Redlands
Steve Liang, University of Calgary, Canada
Ed Parsons, Google
Published report
Editorial: Next Generation Digital Earth
International Journal of Spatial Data
Infrastructure Research 3: 146-167 (2008)
http://ijsdir.jrc.ec.europa.eu/index.php/ijsdir/arti
cle/viewFile/119/99
An eight-point vision
1. Not one Digital Earth, but multiple
connected globes/infrastructures
addressing the needs of different
audiences: citizens, communities,
policymakers, scientists, educators.
2. Problem oriented: e.g. environment, health,
societal benefit areas
3. Allowing search through time and space to
find similar/analog situations with real-time
data from both sensors and humans
4. Asking questions about change,
identification of anomalies in space in both
human and environmental domains
5. Enabling access to data, information,
services, and models as well as scenarios
and forecasts: from simple queries to
complex analyses across the environmental
and social domains
6. Supporting the visualization of abstract
concepts and data types (e.g. low income,
poor health, and semantics)
7. Based on open access, and participation
across multiple technological platforms and
media (e.g. text, voice and multi-media)
8. Engaging, interactive, exploratory, and a
laboratory for learning and for
multidisciplinary education and science.
Back to discrete global grids
• Two dimensional
– representing the ellipsoid, elevations above and
below it
– three-dimensional features
• Google Sketchup integrated with Google Earth
• Three dimensional
– representing the solid Earth
• opening connections to other sciences
– how to handle the ellipsoid as a specific surface?
– what about the geoid?
Spheroid Degenerated-Octree Grid (SDOG)
Prof WU Lixin, Beijing Normal University
International Society for Digital Earth
• Next-generation visioning meeting, Beijing,
March 2011
• Symposium in Perth, August 2011
• Long paper
– Craglia M, de Bie K, Jackson D, Pesaresi M, Remetey-Fülöpp G,
Wang C, Annoni A, Bian L, Campbell F, Ehlers M, van Genderen
J, Goodchild MF, Guo H, Lewis A, Simpson R, Skidmore A,
Woodgate P (2012) Digital Earth 2020: towards a vision for the
next decade. International Journal of Digital Earth 5(1): 4-21
• Forthcoming short paper in PNAS
Earth information:
a basic human right?
• We are all invested in the future of the planet
– it’s the only one we will ever have
• National governments have less control over the flow
of information
• DE facilitates access as never before
• DE can offer effective communication between
science and citizen
– about the planet’s state and future
• Greater emphasis on prediction, how the planet
works
– than in the Gore speech or current DE implementations
What’s missing?
• Commercial software as a 90% solution
– able to satisfy 90% of applications
• but applications will self-select
• What don’t the 90% care about?
– scientific replicability
• no black box
– provenance
• few metadata
– scientific rigor
– principles of the scientific method are absolute
Improving scientific communication
• (Scientist) Only a minority of people are
capable of understanding the limitations of
science
– only a minority can be trusted with data and
results
• (Citizen) Scientists are reluctant to
communicate in terms that the citizen can
understand
– accepting 90% solutions doesn’t help
Where is this headed?
• Not the virtual reality of Gore’s speech
– a separate, mirror world
• An augmented reality
– in which technology provides information that is
beyond our senses
• A world in which physical and virtual realities
are fully integrated
– technology is largely invisible and
incomprehensible
– a new kind of incomplete awareness, control
– at once exciting, powerful, frightening
Concluding points
• Virtual globes have come a long way since
1998
• Much remains to be done
– a new generation is needed
• A concerted effort is needed to define,
promote, and develop the next generation
• Two major elements:
– communication between science and the citizen
– achieving scientific rigor
• Are these two objectives compatible?