LESSON 4: LEVELING METHODS Flashcards
A branch of surveying that deals with the measurement of the elevation of different points with respect to a fixed line call datum. Its goal is to establish, verify, or measure the height of specified points in relation to the datum.
LEVELING
The most used method of leveling. In this method, measurements are observed directly from the leveling instrument.
DIRECT LEVELING
Performed only when the points are nearer to each other without
any obstacles.
Simple Leveling
Performed when the distance and the elevation between two points is too great, and if there are obstacles intervening
Differential Leveling
Performed when the benchmark is very far from the workstation. (not highly precise)
Fly Leveling
Generally adopted to find elevation of points along a line
Profile Leveling
Known as longitudinal sectioning
Profile Leveling
A particularly accurate method of differential leveling which uses highly accurate levels and more rigorous procedures
Precise Leveling
Performed when it is not possible to locate the leveling instrument in between the inter-visible points
Reciprocal Leveling
When the elevation of points or the difference between points is measured from the observed horizontal distances and vertical angles in the field
TRIGONOMETRIC LEVELING
Known as indirect leveling
TRIGONOMETRIC LEVELING
Another indirect leveling where differences in height are determined by measuring the differences in atmospheric pressure at various elevations.
BAROMETRIC LEVELING
A modified form of trigonometric leveling in which the tachometer principle is used to determine the elevation of points.
STADIA LEVELING
It is more accurate and suitable in hilly terrains
STADIA LEVELING
The amount by which the horizontal line departs from the earth’s surface (which is a level surface)
effect of earth’s curvature
