Leumas Physics

Relativistic Doppler Effect (Longitudinal)

fp = f·sqrt((1 - beta) / (1 + beta))

What it says

The observed frequency of light from a source receding along the line of sight at speed fraction beta = v/c is red-shifted relative to the emitted frequency. For an approaching source use a negative beta, which raises the observed frequency.

Symbols

SymbolQuantityDimension
fpObserved frequency (Hz)T^-1
fSource frequency (Hz)T^-1
betaSpeed as fraction of c, v/c (dimensionless)1

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Connects to

Filed under Relativity · derive through it in the explorer