IEVref: 702-02-22 ID: Language: en Status: Standard Term: group velocity Synonym1: Synonym2: Synonym3: Symbol: $|{\stackrel{\to }{v}}_{\text{g}}|$ Definition: the velocity vector at a point, in a propagation medium, of a signal which may be ideally represented by two superimposed sinusoidal waves of equal amplitude and slightly different frequencies approaching a common limiting value NOTE – In the most general case the reciprocal of the magnitude $|{\stackrel{\to }{v}}_{\text{g}}|$ of the group velocity vector is equal to the derivative of the reciprocal of the wavelength λ with respect to the frequency f: $\frac{1}{|{\stackrel{\to }{v}}_{\text{g}}|}=\frac{\text{d}\left({\lambda }^{-1}\right)}{\text{d}f}$ Publication date: 1992-03 Source: Replaces: Internal notes: 2017-06-02: Cleanup - Remove Attached Image 702-02-22-symb.gif 2017-06-02: Cleanup - Remove Attached Image 702-02-221.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: