The larger political jurisdictions of the world's most affluent
countries, including many US counties and cities, have available
to them high quality and cost-effective digital mapping products
based on ever-improving satellite and computer technologies.
However, technology transfer to the majority of the world's
countries has been slow, leaving the vast majority of the
world dependent on sub-standard and costly conventional surveying
techniques. This is particularly true with Global Positioning
System (GPS) technology transfer to most of Africa, Asia,
South America and Eastern Europe. These areas are effectively
left without the means to enjoy most of the benefits of GPS
technology.
GPS work involves the reconnaissance, monumentation, observation
and adjustment of dispersed points in order to calculate intervening
locations and elevations of an object on the surface of the
earth. This information can then be combined with features
captured from aerial or by remote sensing satellite images
to produce necessary scale accurate digital maps or Geographic
Information System (GIS) basemaps.
GPS technology can now be used to provide millimeter level
positional accuracy. However, the system requires control
points of higher accuracy to achieve desired application accuracy.
In North America and some European countries a High Accuracy
Reference Network of known high order points has been established.
These known points allow the collection of intermediate project-specific
points to be both accurate and affordable. For a variety of
reasons, investment in this type of network has been slow
to come to most of the rest of the world. Thus, large populations
of potential beneficiaries are unable to take advantage of
accurate and affordable end-user GPS applications.
Selection and field location of the appropriate number of
Global Positioning System (GPS) ground control points is critical
to the successful development and implementation of user-specific
applications. These ground control points form the backbone
of subsequent mapping, engineering or Geographic Information
System (GIS) projects and control the accuracy, geometry,
authenticity, and, ultimately, determine the success or failure
of these endeavors.
Only through academic research and applied practice does one
gain the necessary expertise to optimize GPS applications,
whether on a country-wide or project-specific basis. EMI has
this experience.
