- qspec.doppler ( f , v , alpha , return_frame = 'atom' )[source]
The Doppler-shifted frequency $f^\prime = \begin{cases}f\gamma(v)(1 - \frac{v}{c}\cos(\alpha)), & \mathrm{atom}\\ f[\gamma(v)(1 - \frac{v}{c}\cos(\alpha))]^{-1}, & \mathrm{lab}\end{cases}$
- Parameters:
-
- farray_like
The frequency $f$ of light (arb. units).
- varray_like
The velocity $v$ of a body (m/s).
- alphaarray_like
The angle $\alpha$ between the velocity- and the light-vector in the laboratory frame (rad).
- return_framestr
The coordinate system for which the frequency is returned. Can be either
'atom'
or'lab'
.
- Returns:
-
- outndarray
the Doppler-shifted frequency $f^\prime$ in either the rest frame of the atom or the laboratory frame ([
f
]).
- Raises:
-
- ValueError
return_frame
must be either'atom'
or'lab'
.