Measurement of vertical angle with theodolite including example
By Structural Community in Surveying
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Vertical angle
It is the angle in the vertical plane between horizontal line passing through the intersection of cross hairs and inclined line joining intersection of cross hairs and the point being observed.
Circle reading in case of vertical angle
During Face left vertical angle will be computed in the following manner,
When angle of elevation, vertical angle = 90° - Circle reading.
When angle of depression, vertical angle = Circle reading - 90°.
Now, during Face right vertical angle will be computed in th following manner,
When angle of elevation, vertical angle = Circle reading - 270°.
When angle of depression, vertical angle = 270° - Circle reading.
Example for method of booking
Angle | Face | Circle reading (° ′ ″) | Angle value (° ′ ″) | Mean (° ′ ″) | Remarks |
|---|---|---|---|---|---|
* | L | 69 58 30 | 20 01 30 | 20 01 45(+ve) | Elevation |
| R | 290 02 00 | 20 02 00 |
In case of angle of elevation value of vertical angle will be +ve while in case of depression it will be -ve.
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