The incidence angle more correctly describes the relationship between a radar beam and a surface, but the actual surface is usually assumed to be horizontal.
入射角依存性
incident angle dependence
入射角度は指定された角度未満である。
The angle of incidence is less than or equal to a given angle.
When light passes from the first isotropic medium into the second, the ratio of the sine of the angle of incidence, i, to that of the angle of refraction, r, is constant with regard to these two media and has no relation to the angle of incidence. This ratio is called the refractive index of the second medium with respect to the first, or the relative refractive index, n.〔【出典】第十六改正日本薬局方(平成23年3月24日 厚生労働省告示第65号)〕