What is levelling? ?

Levelling is the process of measuring and determining the height or elevation of a point or points on the Earth's surface relative to a known reference point, such as sea level. This is typically done using a levelling instrument, such as a level or a theodolite, and a series of measurements taken at different points to create a level surface or determine the slope of the land. Levelling is commonly used in construction, surveying, and engineering to ensure accuracy and precision in measurements and calculations.

Levelling is the process of determining the height or elevation of points on the Earth's surface relative to a known datum. Levelling is used to create topographic maps, to design and construct roads, bridges, and other structures, and to monitor changes in land elevation over time.

There are two main types of levelling: spirit levelling and laser levelling. Spirit levelling uses a spirit level to measure the slope of a line of sight. Laser levelling uses a laser beam to project a level plane.

Spirit levelling is the traditional method of levelling. It is accurate and reliable, but it is also slow and labour-intensive. Laser levelling is a faster and more efficient method of levelling. It is less accurate than spirit levelling, but it is sufficient for most applications.

Levelling is an important tool for a variety of applications. It is used to create topographic maps, to design and construct roads, bridges, and other structures, and to monitor changes in land elevation over time.