6865 Methods of Tacheometry (2).pptx USES

tacheo

1. Methods of Tacheometry Present by : 6865 H.D.A.N.Nishshanka 1

2. Content Introduction Principles of Tacheometry Equipment Used Type of Tacheometry method Stadia method Tangential method Advantages of Tacheometry Conclusion 2

3. Introduction Definition A surveying method for measuring distances indirectly using angles and staff readings. Purpose Used for topographic surveys and mapping 3

4. Principles of Tacheometry The principle of t a cheometry is based on property of isosceles triangles, where the ratio of distance of the base from apex and length of the base is always constant. 4

5. Equipment Used 5

6. Types of Tacheometric Methods 6

7. Stadia Tacheometry In this systems staff intercepts, at a pair of stadia hairs present at diaphragm, are considered. The stadia system consists of two methods: Fixed-hair method Movable-hair method 7

8. Fixed Hair Method In this method, stadia hairs are kept at fixed interval and the staff interval or intercept (corresponding to the stadia hairs) on the leveling staff varies. Staff intercept depends upon the distance between the instrument station and the staff. 8

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10. General Tacheometric Equation D = (f/ i )S + ( f+d ) 10

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13. Moveable hair method In this method, the staff interval is kept constant by changing the distance between the stadia hairs. Targets on the staff are fixed at a known interval and the stadia hairs are adjusted to bisect the upper target at the upper hair and the lower target at the lower hair. 13

14. Tangential Method No stadia hairs. Leveling staff with vanes or target at known distance. Horizontal and vertical distances are measured by measuring angles of elevation or depression. 14

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16. Advantages of Tacheometry Rapid data collection over large areas. Reduces the need for extensive chain measurements. Useful in rough terrain where traditional methods are difficult 16

17. Conclusion Tacheometry is an invaluable method in surveying that streamlines the process of distance measurement through the use of specialized instruments like tacheometers. By utilizing principles of trigonometry and angle measurement, tacheometry allows for rapid data collection, making it especially useful in topographic surveys, civil engineering, and land development projects. 17

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