2. Surveying
Surveying is define as an art of determining
the relative positions of points on, above or
beneath the surface of the earth by the
measurements of horizontal and vertical
distance, angles and directions.
Objective:- The primary object of a survey is
to prepare a plan or map.
4. Uses of Surveying
Surveying may be regarded as an art and
science of map making.
All engineering and construction projects
extending over large such as high ways,
railways, irrigation, water supply etc, are
based upon elaborate and complete surveys.
In all engineering projects the preparation of
accurate plans and sections is the first
necessity, for which surveying is essential.
6. Plan surveying
In plan surveying the curvature of the earth is
not taken into account, as the surveys extend
only over small areas.
The degree of accuracy required in this type
of surveying is comparatively low.
If the area of survey is less than 150sq.km it is
considered as plan.
Plan surveys are done for engineering
projects on large scale such as factories,
bridge, dams, high way, railway, etc, and also
for establishing boundaries.
7.
8. Geodetic surveying
In geodetic surveying, also called
trigonometrical surveying, it is necessary to
take into account the curvature of the earth,
since large distances and areas are covered.
The geodetic surveying deals with fixing
widely spaced control points and it is carried
out in our country by the great trigonometrical
survey department of India.
9.
10. Classification of
surveying
surveying is classified on the basis of their
usage as follows:
I. Based on the nature of the field survey
1) Land surveying
i. Topographical surveys
ii. Cadastral surveys
iii. City surveys
2) Marine (or) navigation surveying
3) Astronomical surveying
11. II. Based on the object of survey
1. Engineering survey
2. Military survey
3. Mine survey
4. Geological survey
5. Archeological survey
III. Based on the instruments used
1. Chain surveying
2. Compass surveying
3. Levelling
4. Theodolite surveying
