  In this work we present a set of synthetic observations that mimic the
properties of the Integral Field Spectroscopy (IFS) survey CALIFA, generated
using radiative transfer techniques applied to hydrodynamical simulations of
galaxies in a cosmological context. The simulated spatially-resolved spectra
include stellar and nebular emission, kinematic broadening of the lines, and
dust extinction and scattering. The results of the radiative transfer
simulations have been post-processed to reproduce the main properties of the
CALIFA V500 and V1200 observational setups. The data has been further formatted
to mimic the CALIFA survey in terms of field of view size, spectral range and
sampling. We have included the effect of the spatial and spectral Point Spread
Functions affecting CALIFA observations, and added detector noise after
characterizing it on a sample of 20 galaxies. The simulated datacubes are
suited to be analyzed by the same algorithms used on real IFS data. In order to
provide a benchmark to compare the results obtained applying IFS observational
techniques to our synthetic datacubes, and test the calibration and accuracy of
the analysis tools, we have computed the spatially-resolved properties of the
simulations. Hence, we provide maps derived directly from the hydrodynamical
snapshots or the noiseless spectra, in a way that is consistent with the values
recovered by the observational analysis algorithms. Both the synthetic
observations and the product datacubes are public and can be found in the
collaboration website http://astro.ft.uam.es/selgifs/data_challenge/.
