In astronomy and surveying, altitude (sometimes called elevation) is one of the two coordinates of the horizontal coordinate system.

Altitude refers to the vertical angle measured from the geometric horizon (0°) towards the zenith (+90°). It can also take negative values for objects below the horizon, down to the nadir (-90°). Although some will use the term height instead of altitude, this is not recommended as height is usually understood to be a linear distance unit, to be expressed in meters (or any other length unit), and not an angular distance.

The term zenith distance is more often used in astronomy and is the complement of the altitude. That is: 0° in the zenith, 90° on the horizon, up to 180° at the nadir.

See also

• Altitude
• Elevation
• Elevation (ballistics)

External Links

• Solar Altitude function for Excel, CAD or your other programs. The Sun API is free and extremely accurate. For Windows Computers.

Celestial coordinate system | Spherical astronomy

Altezza (astronomia)