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The radio velocity convention
Starting from Eq. 4, we obtain to first order in
 |
(6) |
In this case, we can establish a linear velocity scale (see
Sect. 1.3.2)
 |
(7) |
This linear velocity scale is only a first order approximation, which is
called the radio velocity convention. Indeed, it is well adapted to the
radio spectrometer because 1) their natural output is a spectral axis
regularly spaced in frequency and 2) the radio velocity convention gives a
linear relation between the velocity and the frequency scale. This is why
this convention is the default in CLASS.
Gildas manager
2015-03-01