Global Positioning System Reference
In-Depth Information
Many new markup languages have emerged and this movement in computer
science is gradually becoming the way most new computer information is being
structured. For example, XML is at the heart of Microsoft's .Net initiative and is
the way applications encode information. The next stage of the Web revolution,
which is the main focus of Berners-Lee's activities in the World Wide Web,
concerns the Semantic Web. The World Wide Web Consortium (W3C) is the
main standards body for the Web and it is working on the necessary framework so
that all fields of information can be more meaningful and accessible to both
humans and machines and thus advance the science of machine learning and
artificial intelligence (or AI). Chapter 9 will discuss its implication for Whereness.
Some areas of knowledge are ahead of others in the creation of markup
languages but we are fortunate that the geographical sciences are an early adopter!
Two geographical languages will now be described.
Keyhole Markup Language (KML) is the standard that is used by Google and
is relevant to anyone using its API. It includes definitions of latitudes, longitudes,
headings, ranges and so on, and is aimed at geographic visualizations.
Geographic Markup Language (GML) is more general and is a standard
defined by the Open Geographical Consortium (OGC) that describes geographical
features. It can be used for several purposes including computer modeling (i.e,
creating software models of either an existing geography or a virtual geography to
solve some problem) or for the interchange of information between proprietary
GIS databases. The OGC is extending its standards into new areas, for example,
creating a sensor modeling language for sensing systems.
8.7
Open Mapping
In this section we consider the role of openness in mapping, as opposed to a
conventional commercial and proprietary approach where how and what is done
are trade secrets. Openness assumes that although some things may be patented
and require licenses, these will be made available so that a standardized approach
may be adopted across an industry. Other things will be freely available but
legally protected to prevent their being wrapped up within proprietary products.
If Web 2.0 is changing fundamentally the way in which digital maps are used
by people, the advent of open mapping is likely to change the future of the maps
themselves. As GPS-enabled consumer equipment gets cheaper and more
intelligent, the ability to collect geographical information will grow, especially if
the function becomes entirely automatic. In Section 8.5.1 we have seen how
traffic congestion can be detected by navigation units; a logical extension is to use
the GPS track-logs to make maps and then to share them.
Traditional maps are made by ground surveying, aerial photography (either
from aircraft of more recently from space), using lidar (light, detection, and
ranging), which is the optical equivalent of radar, and by professional satellite
positioning equipment. Small numbers of highly skilled professionals use
