Monostatic and bistatic reverberation statistics west of the Mid-Atlantic Ridge

Monostatic and bistatic reverberation of highly resolved signals from very rough bottoms at one site is statistically analyzed. Scattering at a mean f requency of about 230 Hz from a large number of bottom footprints is consid ered. The reverberation envelope is found to be non-Rayleigh, with the degr ee of departure from Rayleigh dependent upon the bottom grazing angle for t wo cases considered, theta(g)approximate to 5 degrees and 40 degrees, and u pon the bistatic angle in the entire range, phi approximate to 0 degrees to 180 degrees. These rough bottom observations can be explained by adopting a continuous scattering model having a Rayleigh envelope, added to a discre te scattering model (arising from a small number of individual features wit hin the sonar footprint) having a distinctly non-Rayleigh envelope. These m odels, plus a heuristic mechanism of self-selection within the discrete sca ttering model, arguably explain the observed angle dependence of the reverb eration statistics. (C) 1999, Acoustical Society of America. [S0001-4966(99 )05010-9].