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DEFINITIONS OF SURVEYING In general, surveying is performed to determine the relative location or positioning of points on or near the earth's surface. More specifically, surveying is the science of making measurements, relative to known or assumed datum’s and standards, and applying the principles of mathematics to such measurements to determine existing or future horizontal and vertical position, from area, magnitude, boundaries, and extent of land parcels and topographical features. Surveying or land surveying is the technique and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them. These points are usually on the surface of the Earth , and they are often used to establish land maps and boundaries for ownership or governmental purposes American Congress on Surveying and Mapping (ACSM) Provide an alternative definition of surveying as the science and art of making all essent

PROCEDURE TO CONSIDER IN CHAIN SURVEY Chain survey is of two types 1.                               Open traverse 2.                               Closed traverse Before starting the survey 1.                               Make a sketch of the area to be surveyed and locate all the prominent objects in it. 2.                               Divide the area included in the sketch into convenient number of triangles and mark vertices on the ground by wooden pegs 3.                               Determine the magnetic north with the help of magnetic compass While dividing the area into triangles, make sure that the vertices of the triangles or station points are free from obstacles and are easily accessible. And that 1.                               The number of stations are as small as possible 2.                               The triangles are equilateral or near equilateral 3.                               The size of triangles are as large as possi

PLANE TABLE SURVEYING Plane table is a graphical method of surveying in which the field works and the plotting is done simultaneously. It is particularly adopting in small mapping. Plane table surveying is used for locating the field computation of area of field. Merits: 1.       It is most suitable for preparing small scale map or surveying small area. 2.       It is most rapid method. 3.       Field book is not necessary. 4.       No great skill is required for satisfactory map. 5.       It is particularly suitable for magnetic area where prismatic compass is not reliable. 6.       Contour and irregular object may be represented accurately. 7.       It is less costly. Demerits: 1.       Plane Table Essentially a tropical instruments. 2.       It is not suitable to work in wet climate. 3.       There are several accessories to be carried out and therefore they are likely to be lost. 4.       It is not suitable for accurate work. Parts of plane Table:

PRISMATIC COMPASS SURVEY We have seen how chain surveying is based on the measurement of horizontal distances. Even if where measurement of angles becomes necessary we resort to measurement of tie lines. Suppose we have to construct a quadrilateral ABCD. If we know the angles A, B, C and D and any two of the sides we can make this figure. Another way we can draw this figure is by knowing the angles of each line AB, BC, CD, and DA and AAC make with a north south line. In the later case we will need to know the length of only one line. The prismatic compass surveying is based on principles of measuring the angles that different lines make with respect to N-S line. Only one line is measured to maintain the scale relationships between the ground and map details. Prismatic compass To determine the angle each line makes with a north –south line we make use of prismatic compass Figure 1            Prismatic Compass                             Prismatic compass is like any

  THE MEANING AND CATEGORIES OF SURVEYING In general, surveying is performed to determine the relative location or positioning of points on or near the earth's surface. More specifically, surveying is the science of making measurements, relative to known or assumed datum’s and standards, and applying the principles of mathematics to such measurements to determine existing or future horizontal and vertical position, from area, magnitude, boundaries, and extent of land parcels and topographical features. Surveying or land surveying is the technique and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them. These points are usually on the surface of the Earth , and they are often used to establish land maps and boundaries for ownership or governmental purposes American Congress on Surveying and Mapping (ACSM) Provide an alternative definition of surveying as the science and art of