  Even though the existence of intermediate-mass black holes (IMBHs, black
holes with masses ranging between $10^{2-4}\,M_{\odot}$) has not yet been
corroborated observationally, these objects are of high interest for
astrophysics. Our understanding of the formation and evolution of supermassive
black holes (SMBHs), as well as galaxy evolution modeling and cosmography would
dramatically change if an IMBH were to be observed. From a point of view of
traditional photon-based astronomy, {which relies on the monitoring of
innermost stellar kinematics}, the {\em direct} detection of an IMBH seems to
be rather far in the future. However, the prospect of the detection and
characterization of an IMBH has good chances in lower-frequency
gravitational-wave (GW) astrophysics using ground-based detectors such as LIGO,
Virgo and the future Einstein Telescope (ET). We present an analysis of the
signal of a system of a binary of IMBHs (BBH from now onwards) based on a
waveform model obtained with numerical relativity simulations coupled with
post-Newtonian calculations at the highest available order. IMBH binaries with
total masses between $200-20000\,M_\odot$ would produce significant
signal-to-noise ratios (SNRs) in advanced LIGO and Virgo and the ET. We have
computed the expected event rate of IMBH binary coalescences for different
configurations of the binary, finding interesting values that depend on the
spin of the IMBHs. The prospects for IMBH detection and characterization with
ground-based GW observatories would not only provide us with a robust test of
general relativity, but would also corroborate the existence of these systems.
Such detections should allow astrophysicists to probe the stellar environments
of IMBHs and their formation processes.
