steradian[stə rā′dē ən]
the basic unit of solid angular measure in the SI system, equal to the solid angle subtended at the center of a sphere by an area, on its surface, that is equal to the square of its radius: one sphere equals 4π steradians: abbrev. sr
Origin of steradianste(reo)- + radian
A unit of measure equal to the solid angle subtended at the center of a sphere by an area on the surface of the sphere that is equal to the radius squared. The total solid angle of a sphere is 4&pgr; steradians.
Origin of steradianste(reo)– + radian.
If A = r2 then solid angle &OHgr; = 1 sr.
ste(reo) + radian