  Atom interferometry detectors like AION, ZAIGA, and AEDGE will be able to
detect gravitational waves (GWs) at dHz covering the band between large
space-based laser interferometers LISA/TianQin/Taiji and ground-based
facilities LIGO/Virgo/KAGRA. They will detect the late inspiral and merger of
GW sources containing intermediate-mass black holes (IMBHs) in the mass range
$10^2-10^5\,{\rm M_\odot}$. We study how accurately the parameters of an IMBH
binary can be measured using the noise curve of AION. Furthermore, we propose a
detection scheme where the early inspiral of the binary is detected using the
regular broadband mode while the merger is detected using the resonant mode. We
find that by using such a detection scheme the signal-to-noise ratio (SNR) of
the detection as well as the detection accuracy of the parameters can be
enhanced compared to the full detection of the signal using the broadband mode.
We, further, assess the impact of the necessary detection gap while switching
from broadband to resonant mode studying the case of a short ($30\,{\rm s}$)
and a long ($600\,{\rm s}$) gap. We find that the improvement in SNR and
detection accuracy is bigger for the shorter gap but that even in the case of
the long gap such a scheme can be beneficial.
