Angle of incidence (optics)

The ray can be formed by any waves, such as optical, acoustic, microwave, and X-ray.

In computer graphics and geography, the angle of incidence is also known as the illumination angle of a surface with a light source, such as the Earth's surface and the Sun.

[2] This means that the illumination angle of a certain point on Earth's surface is 0° if the Sun is precisely overhead and that it is 90° at sunset or sunrise.

"[citation needed] Grazing incidence diffraction is used in X-ray spectroscopy and atom optics, where significant reflection can be achieved only at small values of the grazing angle.

Ridged mirrors are designed to reflect atoms coming at a small grazing angle.