Surveying is a branch of engineering that deals with determining the relative position of different features on, above, or below ground level. Surveying deals with both measurements say horizontal and vertical.
Classification Of Surveying Could Be Done In Two Ways
There are two basic types of surveying.
- Primary Classification Of Surveying
- Secondary Classification Of Surveying
Primary Classification Of Surveying
Plane surveying is used for small projects and small areas. We know that the earth is oblate spheroid in shape and hence while doing measurements we should account this feature into consideration.
But, for small projects, we can neglect the spherical shape of the earth. As the error is negligible, it is reasonable to employ plane surveying.
It considers the curvature of the earth in calculation and measurement. This is used for making the map of counties, locating topographical features of the earth, etc. Geodetic surveying is conducted by The Survey Of India department and is used for an area of more than 250 square kilometers.
Geodetic Surveying is also called trigonometric surveying.
Based on instruments
Compass surveying is done by either the surveyor’s compass or prismatic compass. It is used to take angular measurements.
At present, there are two types of compass used widely in the field.
1. Prismatic Compass and
2. Surveyors Compass.
Plane Table Surveying
In the plane table surveying, data is directly plotted on the drawing sheet. It is a very quick method of plotting the drawings though less accurate.
Generally, theodolite surveying is used for traversing.
Tacheometry is the branch of surveying in which the linear measurements are calculated by taking angular measurements. Theodolites are used for this purpose.
This type of survey used the preparation of maps with photographs taken from a plane or a drone.
In chain surveying, only linear measurements are taken. Chain surveying uses ranging rod, chains, pegs, arrows, and tapes.
Based On Methods
Based On The Object Of Surveying
It is to study the monuments. You can get more about archeological survey with this link.
Based On The Nature Of The Field
Land surveying is further divided into the following classes.
- Topographical Surveying – It is done to determine the natural features of the country
- Cadastral Surveying – This is carried out to determine the boundaries of field, estate, house etc.
- city surveying – It is done to locate streets, water supply pipes network and sewage pipe network
- Engineering surveying – It is done to prepare map of project.
It is related to determining the feature of the surface of the ocean. Buoys and sounding poles are some of the basic instruments used in this survey.
It is related to locating the position of ground points based on the position of stars in the sun. Many times the astronomical survey is used as a verification method.
You may also like to read Plane Table Surveying
Parallelism is the principle of plane table surveying.
There are two types of the traverse, namely Closed Traverse and the Open Traverse in surveying.