Forward scatter
（重定向自Forward scattering）
![Saturn eclipses the Sun, as seen from the Cassini–Huygens space probe. The forward scattering of light makes the faint outer rings more obvious.](/Images/godic/202501/14/Saturn_eclipse0604.jpg")
In telecommunication and astronomy, forward scatter is the deflection—by diffraction, nonhomogeneous refraction, or nonspecular reflection by particulate matter of dimensions that are large with respect to the wavelength in question but small with respect to the beam diameter—of a portion of an incident electromagnetic wave, in such a manner that the energy so deflected propagates in a direction that is within 90° of the direction of propagation of the incident wave (i.e., the phase angle is greater than 90°).