This monograph is devoted to the systematic presentation of the theory
of sound- wave propagation in layered structures. These structures can
be man-made, such as ultrasonic filters, lenses, surface-wave delay
lines, or natural media, such as the ocean and the atmosphere, with
their marked horizontal stratification. A related problem is the
propagation of elastic (seismic) waves in the earth's crust These topics
have been treated rather completely in the book by L. M. Brek- hovskikh,
Waves in Layered Media, the English version of the second edition of
which was published by Academic Press in 1980. Due to progress in
experimental and computer technology it has become possible to analyze
the influence of factors such as medium motion and density
stratification upon the propagation of sound waves. Much attention has
been paid to propagation theory in near-stratified media, Le., media
with small deviations from strict stratification. Interesting results
have also been obtained in the fields of acoustics which had been
previously considered to be "completely" developed. For these reasons,
and also because of the inflow of researchers from the related fields of
physics and mathematics, the circle of persons and research groups
engaged in the study of sound propagation has rather expanded.
Therefore, the appearance of a new summary review of the field of
acoustics of layered media has become highly desirable. Since Waves in
Layered Media became quite popular, we have tried to retain its positive
features and general structure.