Doublets analysis techniques suitable to obtain very accurate determin
ation of arrival times of seismic phases on different stations are pre
sented. These methodologies represent a very powerful tool to recogniz
e the seismotectonic structures and to study the propagation character
istics of seismic waves. The signals similarity analysis, performed in
the frequency and time domain, has been applied to increase the preci
sion in arrival times definition of seismic phases generated by the sa
me sources and having the same path. Tests on synthetic events have sh
own how it is possible to recognize the time delay between digital tra
ces with a sensitivity less than the sample rate. In particular, in th
e time-domain analysis the results obtained using different interpolat
ion functions (parabolic and sine for the cross-correlation operator)
are compared. The analysis slightly suffers from a random noise compon
ent added to the signal, allowing the phase picking of highly noised t
races. On the contrary, the frequency domain analysis offers the best
results in case of high signal-to-noise ratio, while it appears less '
robust' with respect to high noise influence. The application of relat
ive location techniques on the obtained arrival times allows to define
with very high detail the geometrical shape of seismogenetic structur
es. As an example, a case of spatial doublets, recorded by the seismic
network of Northwestern Italy, that occurred during two days in an ar
ea of the Maritime Alps (Italy), has been considered. In spite of the
low magnitude of the events, an accurate reconstruction of the spatial
distribution of the sources was obtained, allowing to discriminate th
e fault plane from the auxiliary one in the focal mechanism solution.