  We show in random matrix theory, microwave measurements, and computer
simulations that the mean free path of a random medium and the strength and
position of an embedded reflector can be determined from radiation scattered by
the system. The mean free path and strength of the reflector are determined
from the statistics of transmission. The statistics of transmission are
independent of the position of the reflector. The reflector's position can be
found, however, from the average dwell time for waves incident from one side of
the sample.
