Isolated mode signals by angle and dispersion

The pattern of focused mode signals has been obtained by a method based on decomposing the modes of a real waveguide over the basis from the modes of a real waveguide with whole numbers and fractions. Variants of a noise-immune representation of isolated mode signals are given. The method is applicable under shallow sea conditions and has been tested on signals calculated for an ideal waveguide and a waveguide with real parameters, and it has been implemented in a full-scale experiment in the Barents Sea at distances of 7–17 km. A 200 Hz wideband signal was initiated by an emitter in resonance with a wide band at a level of 10 dB per 20 Hz, which did not prevent the use of complex wideband signals for compression in individual modes. As a result, a dynamic range higher than 30 dB was obtained for mode signals, which makes it possible to estimate the waveguide parameters and observe weak fluctuations as waves propagate in the medium.