| 释义 |
球面度qiúmiàndù立体角的单位,当立体角的顶点位于球心,它在球面上所截取的面积等于以球半径为边长的正方形面积时,该角就是一球面度。{steradian; SI unit of solid angular measure, equal to the solid angle subtended at the centre of a sphere by an area on the surface of the sphere that is equal to the radius squared} |