Types of Engineering Surveying
Surveying is primarily categorized as below :
1. Plane surveying
2. Geodetic Surveying
Plane surveying refers to the survey in which the earth surface is considered as plane and the curvature of the earth is not taken into consideration. The plane surveys encompass only over lesser areas and the lines linking any two points on the surface of the earth are defined as straight lines and the angles among such lines are assumed as plane angles. To start with plane surveys, understanding of plane geometry and trigonometry is essential. In plane surveys, the covered are must be up to 260 km. In this regard, please remember that the variance in length among the arc and the subtended chord on the earth surface toward a distance of 18.2 km is only 0.1 m.
Geodetic Surveying refers to the particular type of surveying in which the shape of the earth should be considered primarily. All lines assigned in the surface are arc or curved lines and the angles belong to spherical angles. So, it contains spherical trigonometry. These measurements are applied for modifying curvature on maps and plans. Geodetic surveys also offer a wide array of control points over the Earth's surface which produce perfect plane surveys. All Geodetic surveys comprise work of larger magnitude and superior degree of accuracy. The motive of geodetic survey is to obtain the exact position on the surface of the earth. Geodetic surveys are initiated with extreme degree of precision to arrange broadly spaced control points on the earth surface for successive plane surveys.
Categorization of surveying
Surveys are also secondarily categorized with no. of headings which describe the applications or objectiveØÇ of resulting maps.
Categorization is done on the basis of type of field and there are three types of surveying :
1. Land Surveying: It is further divided as i) Topographical survey ii) Cadastrial Survey and iii) City Survey. It usually handles natural or artificial features on land like rivers, streams, lakes, wood, hills, roads, railways, canals, towns, water supply systems, buildings & properties etc.
2. Marine Surveying: Marine or hydrographic survey handles bodies of water for navigation, water supply, harbour works or for assessing mean sea level. The work comprises measurement of discharge of streams, arranging topographic survey of shores and banks, consiering and discovering soundings to ascertain the depth of water as well as observing the variations of the ocean tide.
3. Astronomical Surveying: The astronomical survey provides the surveyor means of ascertaining the absolute location of any point or the absolute location of and direction of any line on the surface of the earth.
There are four types of surveying which are given below:
1. Geological Surveying
2. Mine Surveying
3. Archaeological surveying
4. Military surveying
Categorization on the basis of types of instruments applied:
1. Chain surveying
2. Compass surveying
3. Plane table surveying
4. Theodolite surveying
5. Tacheometric surveying
6. Photographic surveying
Categorization on the basis of techniques used:
1. Triangulation surveying
2. Traverse surveying