The velocity of propagation of a uniform plane wave , given by (a) the product of the wavelength and the frequency divided by (b) the refractive index of the medium in which the wave is propagating. ( 188 ) Note 1: In free space , the refractive index may be considered as unity. Note 2: In free space, the group velocity and the phase velocity are equal.
PHASE VELOCITY
Meaning of PHASE VELOCITY in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012