For imaging applications in randomly inhomogeneous acoustical media,
the results summarized here lead us to the following conclusions:
(1) Single frequency methods (including MUSIC)
are not statistically stable, and therefore cannot be used without
modification
in the presence of significant amounts of spatial heterogeneity in the
acoustic wave speed distribution.
(2) In contrast, time domain methods are statistically stable for any
objective functional having the characteristic that
the random Green's functions appear in Hermitian conjugate
pairs of *g g ^{*}* (Borcea

To isolate the targets in random media, we need either multiple views (using multiple arrays) so we can triangulate, or we need to extract a direct measure of range from the data. In the SAT examples shown here, we used arrival time for the range estimation.

6/7/2002