The processing and adjustment of the GPS observations
were made using the SKI Pro software of Leica,
which was adequate as an analysis tool due to (i) the
small distances of the measured baselines (Dixon,
1991), and (ii) the very high rate (5 s) of sampling
and long recording time (45–60 min) (Lagios et al.,
1998; Lagios, 2000; Ganas et al., 2002)