Land survey

Land surveying is the science (as well as art) of measuring and mapping relative positions above, on or under the surface of the ground. Land survey testing equipments are used in various surveying methods for accurately determining the terrestrial or three-dimensional position of points and distances as well as angles between them. There are a number of land surveying techniques which are used by land surveyors to establish land maps and boundaries for ownership or governmental as well as building design and construction process. Land surveyors use their expert knowledge of geometry, engineering, trigonometry, mathematics, physics, and law for accurate results. This article will help you in knowing the different methods and types of land surveying as well as land surveyor jobs for a clear vision about the whole land surveying process.

Methods and Types of Land Surveying
There are two major aspects of land surveying- the surveyor and the surveying equipment. Precise land surveying instruments and accurate know how about the surveying techniques can only lead to accurate land surveying results. Most of the land surveyors use traditional methods as well as latest technologies to fulfill the surveying requirements of their customers. The prominent land surveying techniques include traditional total station surveying, leveling & 3-D surveying, and survey with Global Positioning System (GPS).

Total Station Surveying
This type of land surveying is carried on with the help of many traditional surveying equipments like theodolite, total station, survey compass etc. Here the key function of the land surveyor is measuring, mapping, and observing. Total station is the most important tool for this type of land surveying. A total station incorporates a distance meter for measuring distances and a theodolite for measuring angles into a single instrument. A total station sends a beam of infrared light toward a prism, generally supported either by a tripod or a pole which reflects off the prism directly back to the total station. It then calculates the distance by measuring the time it takes for the light to return. All the information about angles and distances thus obtained is recorded in a data collector for downloading into a computer later on. Data collector also acts as a field computer which enables the surveyor calculate coordinate geometry in the field and figure out the proper position in which to put stakes.

Leveling & 3-D Surveying
Different methods are used for computing elevations of land. In differential leveling, the difference in elevation between two points on the ground is calculated. This is rather a simple method of land surveying where a ruler is held on the ground to see how high the level is set up above the ground. Then the land surveyor looks at the same ruler placing it on a different spot on the ground to see how high the level is set up above that particular spot. This gives the difference in elevation between the two points. Total station is also used to derive elevations by using geometry and measuring the angles and distances. Global Positioning System is other method used for the purpose which involves intersecting vectors from satellites in space. However, leveling & 3-D surveying is often the most easiest land surveying technique for computing elevations.