Low-mode acoustics of shallow water waveguides

Target strength in oceanic waveguides

“…As our analysis has shown, this quantity most frequently has a complex interference structure, which noticeably Because multistatic underwater observations are initially designed to adapt to the propagation condi tions, the use of the BTS in engineering calculations and estimates of such systems seems important. The possibilities of selecting energy carrying waveguide components, including the use of matched filtering methods, were also investigated in marine experiments [6,11,29,30]. In the acoustic designing of underwater observation systems, which is especially important for a multistatic underwater acoustic observation system, it is necessary to use multiparameter numerical BTS calculation models [3][4][5][6].…”

“…The possibilities of selecting energy carrying waveguide components, including the use of matched filtering methods, were also investigated in marine experiments [6,11,29,30]. In the acoustic designing of underwater observation systems, which is especially important for a multistatic underwater acoustic observation system, it is necessary to use multiparameter numerical BTS calculation models [3][4][5][6]. Note that in engineering calculations using the hydrolocation equation, losses during propagation from the source to the body and from the body to the receiver are estimated separately.…”

“…4a). Narrowband linearly frequency modulated pulses [6,25] are used as the probing signals. It is implied that the arrays span the depth of the waveguide, thus allow ing selection of waveguide modes owing to spatialfrequency filtering and time gating.…”

“…Multistatic hydroacoustic (HA) observation of spa tially localized inhomogeneities is performed using a set of transmitting and receiving systems distributed in an extended ocean region [1][2][3][4][5][6][7][8]. In this case, a signal of each partial projection is determined by the bistatic tar get strength (BTS), which characterizes the value of the body scattered (diffracted) field in a waveguide [9,10].…”

“…Because of the multiwave propagation, the total signal in a waveguide has a complex interference structure, thus impeding observation. Attenuation of this type of interference may consist in separate measurements of each partial waveguide component of a diffracted field and their subsequent accumulation, e.g., incoherent summation [5][6][7][8]. The diffracted signals of individual partial components are separated via spatiotemporal fil tering.…”