Surveying is the art to determine the relative position of object on or below the surface of the earth by measuring horizontal distance between them and prepare a map to any suitable scale.
Classification of surveying-
1) Primary classification –primary surveying can be divided into two type.
a) Plane surveying
b) Geodetic surveying
a) Plane surveying –
• We know that the shape of earth is spheroidal, thus the surface is obviously curve, but in a plane surveying curvature of earth is not taken into consideration.
• This is because plane surveying is carried out over a small area so the surface of earth is considered as plane.
• In a plane surveying line joining two points is consider as a plane line.
• Triangle formed by joining three points is called as plane triangle and angle of this triangle is considered as plane angle. • Plane surveying is done in an area less than $250 \ km^2$
• Plane surveying is conducted by state agencies like the irrigation department, railway department etc.
b) Geodetic survey- • In a geodetic surveying curvature of earth is taken into consideration. This is because geodetic survey carried out over large area.
• In a geodetic survey line joining two points is consider as a curve line.
• The triangle formed by joining three points is considered as a spheroidal triangle and angle of this triangle is considered as a spheroidal angle.
• Geodetic survey carried out over and area exceeding $250 \ km^2$
• Geodetic survey is conducted by survey of India department
2) Secondary surveying-
a) Based on instrument- based on instruments surveying is classified as
• Chain surveying
• Compass surveying
• Plane table surveying
• Theodolite surveying
• Tachometry surveying
• Photographic surveying
b) Based on method- based on method surveying is classified as
• Triangulation surveying
• Traverse surveying
c) Based on object- based on object surveying is classified as
• Geological surveying
• Mine surveying
• Archaeological surveying
• Military surveying
d) Based on nature of fields- based on nature of fields surveying is classified as
• Land surveying
• Marine surveying
• Astronomical surveying