Abstract:
The ATOC95 experiment was conducted in the winter of 1995 with transmission
paths from Pioneer Seamount to Hawaii (range = 3515 km). The internal wave
environment is strongly range dependent, and significant mode coupling occurs to
the late arriving energy. The ability to localize a source is an indication of
the remaining source information in the signal. A mode travel time difference
range estimator was developed and shown to be biased by internal wave-induced
mode coupling. A range estimator was developed which matched the received
wavefronts with those of predicted wavefronts at various ranges. Forward
simulations were done using a frequency interpolation method of the PE, and a
set of random realizations of the Garrett--Munk spectra for internal waves. With
this ensemble of calculations as a forward model, three different measures were
calculated from the data and simulations to do an inversion for the background
internal wave strength in the ocean. A method was developed to simultaneously
invert the source location and the internal wave strength using the mode arrival
time and mode spread as the two observables.