  Tens of thousands of solar-like oscillating stars have been observed by space
missions. Their photometric variability in the Fourier domain can be
parameterized by a sum of two super-Lorentizian functions for granulation and a
Gaussian-shaped power excess for oscillation. The photometric
granulation/oscillation parameters scale with stellar parameters and they can
also make predictions for corresponding parameters in radial velocity
measurements. Based on scaling relations, we simulate realistic radial velocity
time series and examine how the root-mean-square scatter of radial velocity
measurements varies with stellar parameters and different observation
strategies such as the length of integration time and gaps in the time series.
Using stars with extensive spectroscopic observations from the spectrographs
(SONG and HARPS), we measure the granulation amplitude and timescale from the
power spectrum of the radial velocity time series. We compare these
measurements with literature values based on Kepler photometry. We find that
the granulation amplitude in radial velocity can be well predicted from the
photometry and scaling relations. Both granulation timescales in radial
velocity agree with those predicted from photometry for giants and sub-giants.
However, for main-sequence stars, only one granulation timescale in radial
velocity is in agreement with the photometric-based values, while the other
timescale generally lies at lower frequencies compared to the result of
photometry. In conclusion, we show the photometric scaling relations from
Kepler photometry and the scaling relationship to Doppler observations can be
very useful for predicting the photometric and radial velocity stellar
variabilities due to stellar granulation and oscillation.
