Dr. Satyaprakash
GIS Development
[email protected]
Back Sight
Humans have pondered over the ‘shape of the earth’ for more than a millenia. This led to some systematic processes and measurements which were later baptized as ‘Geodetic Surveying’.
Surveying has been traditionally defined as the science and art of determining the relative positions of points above, on, or beneath the surface of the earth, or establishing such points. The purpose of which is to research the form and size of the earth and the geometrical shape and spatial position of the objects on the surface of the ground.
In other words, it is the science to collect, analyze, integrate, manage and apply the geographical data about above and under the ground surface or in the water with features of spatial contribution with all kinds of appropriate approaches and instruments, which aims to make the natural appearances known to the people.
Historically, it was as early as 1400BC that the Egyptians first used surveying to accurately divide land into plots for the purpose of taxation and sometime in 120BC the Greeks developed the science of geometry and used it for precise land division and also standardized the procedures for conducting surveys. They were also the first to develop an instrument (Diopter) for conducting surveys.
However, in 1800AD, during the industrial revolution, surveying became an important aspect for development of public infrastructure, in terms of railroads, canals and roads. This led to the development of more sophisticated instruments and this was the time when science of Geodetic and Plane surveying was developed.
Today, surveying has become a part of our lives and irrespective of whether we realize it or not, it is affecting our daily lives. Whether it is the development or realignment of our neighbourhood road, development of a new shopping mall in the vicinity, the development of a new amusement park, the laying down of the optical fibre cables for more telecommunication lines or the development of a new line for metro rail in our neighbourhood, without surveying, all these would not have been possible.
Some of the common surveying applications have been,
-
- bridge construction,
- roads,
- buildings and
- land development etc.
- to map the earth above and below the sea,
- prepare navigational maps (land, air, sea),
- establish boundaries of public and private lands,
- develop data bases for natural resource management,
- development of engineering data for
The methods of surveying can be classified under major two headings, viz., Geodetic and Plane. Geodetic is one where the spherical shape of the earth is taken into account and it covers large areas and has high accuracy. Plane surveying is concentrated into smaller areas where accuracy requirement is not that stringent and this method considers region as flat, instead of spherical. This is commonly used for most of the work, whereas geodetic surveying is employed for determining shape and size of earth and establishing control points.
