We report on ultrasonic measurements of the propagation operator in a
strongly scattering mesoglass. The backscattered field is shown to display a
deterministic spatial coherence due to a remarkably large memory effect induced
by long recurrent trajectories. Investigation of the recurrent scattering
contribution directly yields the probability for a wave to come back close to
its starting spot. The decay of this quantity with time is shown to change
dramatically near the Anderson localization transition. The singular value
decomposition of the propagation operator reveals the dominance of very intense
recurrent scattering paths near the mobility edge.Comment: 5 pages, 4 figure