Introduction - Ubiquitous Positioning - page 6

The final part of the conclusion paints a vision of what Whereness may be
like in terms of devices and services and what businesses need to do to turn the
vision into a reality.
1.3.5 The Epilogue
Several more technical topics are explained in the Epilogue that may be useful to
people intending to create instances of Whereness technology. It can be ignored
by the more general reader.
1.4 General Principles
1.4.1 Some History and Terminology
To introduce some of the fundamentals of positioning, it is useful to look at how
navigation has developed in the past. Let us consider first what we mean by
navigation. Navigation is associated closely with positioning. It implies the
participation in a journey, from a starting position to another position that is
somewhere else, with perhaps other places passed along the way. We call these
“way points” and can thus consider a journey to be a set of locations or positions
separated in both distance and time. Location can be specified in many ways but
in general there can be a symbolic or language-based reference, such as a place
name or alternatively, a physical reference such as a latitude, longitude, and height
expressed in numerical form, derived perhaps from taking some measurements or
from a map.
Navigation, historically, has had an enormous impact politically, socially, and
economically as mariners learned to find their way out of sight of land. They used
their eyes and simple instruments to observe the movements of the heavenly
bodies (weather permitting) from which they could find latitude and their
orientation and heading. The magnetic compass was used in the Middle Ages, at
first in the form of a natural magnetic iron oxide know as lodestone. It provided a
reliable heading in most places. Today we might describe these traditional
navigation methods as sensing techniques and systems: collecting information by
detecting (or sensing) the presence of physical phenomena.
Maps and their maritime equivalent, charts, were drawn, and as the
understanding of mathematics, geometry, and instrumentation advanced, they
developed from a generally artistic endeavor with largely symbolic information,
into accurate graphical scale drawings. Cartographers eventually found solutions
to the problems of representing the three-dimensional solid and nearly spherical
Earth as a two-dimensional drawing. During the Renaissance when the voyages of
discovery were in progress, they used projections using geometry to distort the
image in various ways. One of the most well known is the Mercator Projection,