classical “quartets” caused by the different multiplicity of their contact with the caustics is performed on the
basis of the experimental materials observed with the use of explosive sound sources. The estimated values of
the phase shift between the signals of the “quartet” significantly differ from those divisible by 90
expected in accordance with the theory. This is possible if the significant (ray) splits at the turn point located at the boundary
between the water layers differing in the sound velocity gradient (with gradient growth with distance from the
axis of the underwater sound channel). In this case, an additional signal is generated that arrives at the receiving
point virtually simultaneously with the principal one, though differing from it by one contact with the caustic.
At a certain limitation of the frequency spectrum, the split signal is accepted as a single summary signal with a
phase shift with respect to the reference one formed in accordance with the vector addition rules. In the exper-
iments analyzed, a series of explosion-generated signals was registered at various distances from the source,
which allowed us to implement certain statistical estimates. Thus, the mean square dispersion of the phase shift
values changed from 16
at a distance of 150 km to 60
at a distance of 510 km from the source; the mean value of the correlation coefficient between the phase-adjusted signal pairs decreased from 0.92 at a distance of
150km to 0.73 at a distance of 510 km from the source.