Taping method: it is possible to measure a distance between two points in vertical line with tape.
Barometric leveling: the barometer is used to find relative elevations of points on the earth’s surface.
Trigonometric leveling: the difference in elevation between two points can be determined by measuring the distance between them and the vertical angle to one point from the other.
Differential leveling: it is the most commonly employed method. A telescope is used to read graduated rod held on fixed points.
Other methods such as GPS, Photogrammetry, Laser device and etc.