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surveying.ppt
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- 2. Introduction to Surveying ►Definition: Surveying is the science and art of determining the relative positions of points above, on, or beneath the earth’s surface and locating the points in the field.
- 3. The work ofthe surveyor consists of 5 phases: 1. Decision Making – selecting method, equipment and final point locations. 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 useable form. 4. Mapping or Data Representation – plotting data to produce a map, plot, or chart in the proper form. 5. Stakeout – locating and establishing monuments or stakes in the proper locations in the field.
- 4. Object of Surveying ►The primary object of survey is the preparation of plan of estate or buildings roads, railways, pipelines, canals, etc. Or to measure area of field, state, nation. ► Object of geodetic surveying is to determine precise positions on the surface of the earth of widely distant points.
- 5. Uses of Surveying ►To prepare a topographical map this shows the hills, valley, rivers, villages, town, etc, of a country. ► To prepare a cadastral map showing the boundaries of fields houses, and other properties. ► To prepare an engineering map to show details like roads, railways, canals, etc.
- 6. Uses of Surveying ►To prepare military map showing roads and railways, communication with different parts of country. ► To prepare contour map and to determine capacity of a reservoirs and ton find the best possible route for roads, railways etc. ► To prepare archeological map including places where ancient relics exist. ► To prepare a geological map showing areas including underground resources
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- 8. A. Primary Classificationor Primary Division : 1. Plane surveying 2. Geodetic surveying
- 9. 1. Plane Surveying The shape of the earth is spherical. Thus the surface is obviously curved. But in plane surveying the curvature of earth is not taken into account. This is because plane surveying is carried out over a small area, so the surface of the earth is considered as a plane. The degree of accuracy required in this type of surveying is completely low. Plane surveying is done on an area of less than 250 sq.km.
- 10. 2. Geodetic surveying In geodetic surveying the curvature of the earth is taken into consideration. It is extended over a large area greater than 250 sq.km. The line joining any two points considered as a curved line. Very refined methods and instruments are used in this type of surveying. In this method very high precision or accuracy is required.
- 11. B. Secondary Classification ►Survey can be classified on different bases: 1. Based on instrument: ► Chain Survey ► Compass survey ► Plane Table survey ► Theodolite survey ► Tacheometric Survey ► Photographic survey
- 12. 2. Based onmethods: ► Triangulation Survey ► Traverse Survey
- 13. 3. Based onObjects: ► Geological survey ► Mine survey ► Archeological Survey ► Military survey
- 14. 4. Based onnature of field ► Land Survey ► Marine survey ► Astronomical survey
- 15. Other Types ofSurveys: 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.
- 16. Other Types ofSurveys: 5. Topographic Surveying – collecting data and preparing maps showing the locations of natural man-made features and elevations of points of 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.