  In this paper, we show that in the presence of large-scale circulation (LSC),
Taylor's hypothesis can be invoked to deduce the energy spectrum in thermal
convection using real space probes, a popular experimental tool. We perform
numerical simulation of turbulent convection in a cube and observe that the
velocity field follows Kolmogorov's spectrum ($k^{-5/3}$). We also record the
velocity time series using real space probes near the lateral walls. The
corresponding frequency spectrum exhibits Kolmogorov's spectrum ($f^{-5/3}$),
thus validating Taylor's hypothesis with the steady LSC playing the role of a
mean velocity field. The aforementioned findings based on real space probes
provide valuable inputs for experimental measurements used for studying the
spectrum of convective turbulence.
