What is altitude?

Altitude is the vertical distance of an object above a fixed reference point. The reference point is usually sea level, but it can also be the ground level at a specific location.

Altitude is used to measure the height of mountains, airplanes, and other objects. It is also used to create topographic maps, which show the elevation of different areas of land.

There are two main types of altitude:

* Absolute altitude is the height of an object above sea level.

* Relative altitude is the height of an object above a specific ground level.

For example, the absolute altitude of Mount Everest is 8,848 meters (29,029 feet). The relative altitude of the top of a hill might be 100 meters (328 feet) above the surrounding ground level.

Altitude can be measured using a variety of instruments, including:

* Altimeters

* Barometers

* GPS receivers

Altimeters measure the air pressure to estimate the altitude of an object. Barometers measure the atmospheric pressure, which can be used to calculate the altitude. GPS receivers use satellites to calculate the position of an object, which can also be used to determine the altitude.

Altitude is an important measurement for a variety of applications, including:

* Aviation

* Navigation

* Meteorology

* Surveying

* Hiking

* Skiing