# Flattening - 1st variant

## Description

Flattening is a measure of the compression of a circle or sphere along a diameter to form an ellipse or an ellipsoid of revolution (spheroid) respectively. Other terms used are ellipticity, or oblateness. The compression factor is b/a in each case. For the ellipse, this factor is also the aspect ratio of the ellipse.

Related formulas## Variables

f | flattening (dimensionless) |

a | larger dimension (semimajor axis) (m) |

b | smaller dimension (semiminor axis) (m) |