The relative positions are determined by measuring distances and angles using various surveying instruments.
The work of the land surveyor consists 5 steps:
1.Decision making – Selecting method & equipment.
2.Fieldwork & data collection – Making measurements and recording data in the field.
3. Computing & data processing – Preparing calculations based upon the recorded data to determine locations in a usable form.
4.Mapping or data representation – Plotting data to produce a map or chart in the proper form.
5.Stakeout – Locating and establishing stakes in the proper locations in the field.
Surveying can be divided primarily into two:
1.Plane surveying.
Relatively small areas (the limit is roughly placed at about 100 square miles) are considered & it is taken that the earth surface is flat. So the curvature of the earth’s surface is not taken into account.
2.Geodetic surveying.
The art of surveying the earth surface considering its shape and size is called geodetic surveying. Geodetic surveying is suitable for finding out the area of any region on the earth surface, the length and directions of the border lines, contour lines and location of basic points.
7 Types of Surveys
1.Photogrammetry – Mapping utilizing data obtained by camera or other sensors carried in airplanes or satellites.
2.Boundary surveying – Establishing property corners, boundaries, and areas of land parcels.
3.Control surveying – Establish a network of horizontal and vertical monuments that serve as a reference framework for other survey projects.
4.Engineering surveying – Providing points and elevations for the building civil engineering projects.
5.Topographic surveying – Collecting data and preparing maps showing the locations of natural man-made features and elevations of points o the ground for multiple uses.
6.Route surveys – Topographic and other surveys for long – narrow projects associated with civil engineering projects. Highways, railroads, pipelines, and transmission lines.
7.Hydrographic surveying – Mapping of shorelines and the bottom of bodies of water.
Types of Errors during the surveying process.
The errors can be classified into three types depending on the source:
Instrumental errors : Occur due to imperfection adjustment of the instrument used.
Personal errors : Occur due to human limitation, such as sense of light.
Natural errors : Caused by change of natural phenomena, such as temperature, humidity…..Etc.