Leveling ODINAFRICAGLOSS Sea Level Training Course Oostende Belgium
Leveling ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
How to ? Set the Level in the field Hold the Staff Take a reading Hand Signal while taking Reading
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
Procedure It is a common practice to use a procedure called stationing. 1. Stations are established at uniform distances along the route. 2. Standard station distance is 100 feet. 3. Half or quarter stations are used when the topography is very variable. 4. The distance from the starting point to the station is used as the station identification. 9
Basic Principle of Leveling • Measures height differences between points n Along a line n Several points from one occupation Leveling rods Line of sight Back sight Fore sight fs bs Dh = bs - fs Gravity Gradient ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
Benchmark (BM) : a reference mark whose elevation is known relative to a given datum. Turning Point : a temporary point whose elevation is determined during the process of leveling; used to establish the Height of Instrument : in leveling, the height of the line of sight of the leveling instrument above the adopted datum; in horizontal angle measurement, the height of the center of the telescope (horizontal axis) above the ground or station mark.
Definitions • Back sight (BS) n The first reading from a new instrument stand point (i. e. take the height to the instrument) • Fore sight (FS) n The last reading from the current instrument station (i. e. give the height to a benchmark) • Intermediate sight (IS) n Any sighting that is not a back sight or fore sight ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
TP BS BS IS IS FS ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
Profile Data Table STA BS HI FS IS ELEV 14
• HI = BS + Elevation • elevation = HI - IS or FS ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
• There are two ways to calculate the levels of the points 1 –the method of Height of Instrument. Collimation Method: • Sum of B. S. – sum of F. S. = last E. L. – First E. L. ODINAFRICA/GLOSS Sea Level Training Course - Oostende, Belgium - 13 -24 Nov. 2006
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