  Coronal seismology is extensively used to estimate properties of the corona,
e.g. the coronal magnetic field strength are derived from oscillations observed
in coronal loops. We present a three-dimensional coronal simulation including a
realistic energy balance in which we observe oscillations of a loop in
synthesised coronal emission. We use these results to test the inversions based
on coronal seismology.
  From the simulation of the corona above an active region we synthesise
extreme ultraviolet (EUV) emission from the model corona. From this we derive
maps of line intensity and Doppler shift providing synthetic data in the same
format as obtained from observations. We fit the (Doppler) oscillation of the
loop in the same fashion as done for observations to derive the oscillation
period and damping time.
  The loop oscillation seen in our model is similar to imaging and
spectroscopic observations of the Sun. The velocity disturbance of the kink
oscillation shows an oscillation period of 52.5s and a damping time of 125s,
both being consistent with the ranges of periods and damping times found in
observation. Using standard coronal seismology techniques, we find an average
magnetic field strength of $B_{\rm kink}=79$G for our loop in the simulation,
while in the loop the field strength drops from some 300G at the coronal base
to 50G at the apex. Using the data from our simulation we can infer what the
average magnetic field derived from coronal seismology actually means. It is
close to the magnetic field strength in a constant cross-section flux tube that
would give the same wave travel time through the loop.
  Our model produced not only a realistic looking loop-dominated corona, but
also provides realistic information on the oscillation properties that can be
used to calibrate and better understand the result from coronal seismology.
