Introduzione e metodi di livellamento

Leveling is a technique to determine the difference in elevation between various points on the Earth.

Elevation is the vertical distance above or below the region’s mean sea level.

Specific points of known elevation, called benchmarks, are established within a region to carry out leveling in that region.

The general methods of leveling are trigonometric, barometric, and spirit leveling.

The elevation of an inaccessible point P can be determined using trigonometric leveling by measuring the horizontal distance and angle to point P. Then, using trigonometric principles, point P’s elevation is determined. 

Barometric leveling can be used to determine the elevation of point C using three altimeters. One is positioned at point C, and the other two are at locations A and B of known elevation. 

Air pressure readings from these altimeters are used to calculate point C’s elevation.

Spirit or direct leveling determines the elevation of point D using leveling instruments by taking vertical measurements to point D with reference to a horizontal line of predetermined elevation. 

Subtracting the vertical measurement from the horizontal line’s elevation gives point D’s elevation.