  The direct discovery of gravitational waves from compact binary systems leads
for the first time to explore the possibility of black hole spectroscopy. Newly
formed black holes produced by coalescing events are copious emitters of
gravitational radiation, in the form of damped sinusoids, the quasi normal
modes. The latter provide a precious source of information on the nature of
gravity in the strong field regime, as they represent a powerful tool to
investigate the validity of the no-hair theorem. In this work we perform a
systematic study on the accuracy with which current and future interferometers
will measure the fundamental parameters of ringdown events, such as frequencies
and damping times. We analyze how these errors affect the estimate of the mass
and the angular momentum of the final black hole, constraining the parameter
space which will lead to the most precise measurements. We explore both single
and multimode events, showing how the uncertainties evolve when multiple
detectors are available. We also prove that, for second generation of
interferometers, a network of instruments is a crucial and necessary ingredient
to perform strong-gravity tests of the no-hair theorem. Finally, we analyze the
constraints that a third generation of detectors may be able to set on the
mode's parameters, comparing the projected bounds against those obtained for
current facilities.
