The paper considers the variability of characteristics of a signal propagating in a shallow-water waveguide under conditions of horizontal refraction. Structure and properties of the sound field in horizontal plane such as the signal shape, its spectrum, and features of the phase and amplitude fronts are studied using the theory of vertical modes and horizontal space-time rays. An analysis of the propagation of chirp signals (270–330 Hz) is carried out for the Shallow Water 2006 experiment, in a situation where the acoustic track is crossed by a moving packet of intense nonlinear internal waves and multipath effects are observed in the horizontal plane Baiey et al., JASA EL, 2011. Space-time rays, corresponding to propagating waveguide modes and the corresponding dynamics of signals are calculated for model constructed on the base of observational oceanographic data obtained in August 2006. The modeling results are compared with experimental data. Work supported by ISF, Grant 946/20.
Manulchev et al. (2025) studied this question.