Bouguer correction

1. An approximation of the Earth's gravitational pull as a function of elevation. The additional mass beneath an object standing on the ground at a high elevation (such as on a mountain) leads to a higher amount of gravitational force. If the strength of gravity at sea level is known, then its value at higher elevations can be approximated using the Bougeur correction. Standardly, the correction equals 0.4186 ρh, where ρ is the assumed average density of the Earth, and h is the difference in altitude between the place where the strength of gravity is known and where it is being approximated. This value is added to the value of gravity at the lower location to yield an approximation of its value at the higher one.
2. Compare free-air correction