A contour line is an imaginary line which connects points of equal elevation. Such lines are drawn on the plan of an area after establishing reduced levels of several points in the area. The contour lines in an area are Read more…
As stated earlier the aim of surveying is to make plans and maps to show various objects on the ground at their relative position to suitable scale. Various steps involved in making the plans are explained in this article. Contouring Read more…
Total station is modern survey equipment which combines the features of electronic theodolite and electromagnetic distance measurement (EDM) instruments. It is also integrated with microprocessor, electronic data collector and storage system. Total Station The instrument can be used to measure Read more…
Theodolite is an instrument which replaced compass and level. It can measure both horizontal and vertical angles. If telescope is kept at zero reading of vertical angle it serves as an ordinary level. In this modern era of electronics equipments Read more…
Types of Direct Levelling The following are the different types of direct levelling: (1) Simple levelling (2) Differential levelling (3) Fly levelling (4) Profile levelling (5) Cross sectioning and (6) Reciprocal levelling. Simple Levelling It is the method used for Read more…
Elevation measurements involve measurements in vertical plane. It is also known as levelling. It may be defined as the art of determining the elevations of given points above or below a datum line or establishing given points of required heights Read more…
The following four methods are available for carrying out plane table survey: 1. Radiation 2. Intersection 3. Traversing 4. Resection. The first two methods are employed for locating details while the other two methods are used for locating position of Read more…
In this method of surveying a table top, similar to drawing board fitted on to a tripod is the main instrument. A drawing sheet is fixed on to the table top, the observations are made to the objects, distances are Read more…
Disadvantage of chain surveying is that, in it only distances are measured and hence area is to be covered with a network of triangles. If the length as well as angle of a line can be measured with respect to Read more…
Chain Surveying Chain survey is suitable in the following cases: Area to be surveyed is comparatively small. Ground is fairly level. Area is open and details to be filled up are simple and less. In chain surveying only linear measurements Read more…