Levelling
Levelling, Important Terminologies In Levelling, Elevation & Altitude, Reduced Level, Mean Sea Level, Bench Marks(B.M)– G.T.S Bench Marks, Permanent Bench Marks, Temporary Bench Marks, Arbitrary Bench Marks. Measurement in Leveling Work- Horizontal Line, Vertical Line, Level Line, Back Sight Reading, Fore Sight Reading, Intermediate Sight Reading. Method to Find Reduced Level- Height of Instrument, Rise and Fall Method. Inverted Staff, Correction Required in Levelling Work- Correction due to Earth Curvature (Cc), Correction due to Refraction (CR), Combined Correction due to Both (C). Distance of Visible Horizon- When height of any one point is considered, When height of both points are considered. Reciprocal Leveling – When the instrument near A, When the instrument near B, Collimation error– When Area is Large, When Area is small, Angular / Inclination Error, Sensitivity of Bubble Tube , The sensitivity of level tube increases with?.
Topics
In this chapter, we detailed discuss about geographic information system, uses of gis, components of gis, global positioning system, remote sensing, type of remote sensing sensor systems.
Compass is a survey instrument used for the measurement of horizontal angles and the bearing of a line of sight.Surveyor Compass and Prismatic Compass are discussed in detailed.