doppler_radio

astropy.units.equivalencies.doppler_radio(rest)[ソース]

戻り速度の無線約束の等価対。

速度と周波数の関係の無線約束は:

\(V = c \frac{f_0 - f}{f_0} ; f(V) = f_0 ( 1 - V/c )\)

パラメータ
restQuantity

標準スペクトル当量(波長、エネルギー、周波数、周波数)がサポートする任意の量。

参考文献

NRAO site defining the conventions

実例.

>>> import astropy.units as u
>>> CO_restfreq = 115.27120*u.GHz  # rest frequency of 12 CO 1-0 in GHz
>>> radio_CO_equiv = u.doppler_radio(CO_restfreq)
>>> measured_freq = 115.2832*u.GHz
>>> radio_velocity = measured_freq.to(u.km/u.s, equivalencies=radio_CO_equiv)
>>> radio_velocity  
<Quantity -31.209092088877583 km / s>