Geography Reference
In-Depth Information
2.5.3 Analysis and modelling
Google Earth is designed primarily as a tool for visualization, and its functionality for
analysis is limited to a few simple measurements of distance and area. GIS users who are
familiar with the much greater analytic power of their software have expressed interest in
adding to the analytic capabilities of Google Earth, and in possible intermediate products.
ESRI's ArcGIS Explorer (www.esri.com/software/arcgis/explorer/index.html) may develop
into a leader in this latter category. Analysis and modelling on the curved surface of the
Earth is far from straightforward, requiring radically different methods from those devised
for a flat two-dimensional world (Raskin, 1994). Yet such capabilities would be invaluable
in the analysis of such global phenomena as climate change and trade.
2.5.4 A global data source
The concept of a global map dates from the nineteenth century, when the first proposals
surfaced for a uniform coverage of the planet's surface. Today we are close to achieving that
goal, given the power of satellite remote sensing and the ability of geobrowsers to integrate
data from a patchwork of sources. At the same time many other sources of geographic data
are in decline, as a result of cutbacks in funding for national mapping agencies, particularly
in less-developed countries. This is especially true of features and properties that cannot be
detected in images, such as placenames and social variables. Google Earth has the potential
to act as a global source and as a technology for integrating data, but its position in the
private sector is problematic. Efforts are under way to adopt standards across competing
geobrowsers, and there are increasingly interesting options for both software and data in
the public domain. Nevertheless, the goal of a global spatial data infrastructure and a single
portal to all that is known about the surface of the Earth remains elusive.
2.6 Conclusions
Google Earth provides at least a first approximation to the vision outlined by Vice-President
Gore in 1998. It has captured the imagination of a vast number of people, many of whom had
no prior experience in any form of geographic information technology. From the perspective
of GIS, it represents a distinct democratization, in which people without any training in the
basic concepts of spatial science are able to access at least some of its tools. This includes
many social scientists, who for the first time have access to comparatively simple ways of
displaying georeferenced data, and gaining the insights that a spatial perspective can provide.
Google Earth and other geobrowsers address what previous generations of developers
had seen as insuperable challenges: feeding vast amounts of data through comparatively
limited Internet pipes, manipulating three-dimensional images in real time, and zooming
through a hierarchical data structure over at least four orders of magnitude of resolution.
The software is robust, and designed with a user interface that a child of 10 can learn in
10 minutes. Nevertheless, the concepts that underlie Google Earth are sophisticated, and
while most are intuitive, others, such as the basis of georeferencing, are highly technical.
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