Convert solid angle between steradian, square degree and full sphere (spat).
Solid angle measures the portion of space seen from a point, just as a plane angle measures the portion of a circle. The steradian (sr) is the SI unit; a full sphere measures 4π sr (about 12.566 sr), also called 1 spat. Select the units and enter a value. For example, 1 sr equals about 3,282.8 square degrees, and a full sphere equals 4π sr.