Solid angle (in spherical coordinates)

Description

In geometry, a solid angle is the two-dimensional angle in three-dimensional space that an object subtends at a point. It is a measure of how large the object appears to an observer looking from that point. In the International System of Units (SI), a solid angle is expressed in a dimensionless unit called a steradian . Any area on a sphere, totaling the square of its radius and observed from its center, subtends precisely one steradian.

Related formulas

Variables

ΩSolid angle (in spherical coordinates) 2)
θThe colatitude (angle from the North pole) (deg)
d_θThe colatitude (diff) (deg)
d_ϕThe longitude (diff) (deg)