Chrysoula Tsogka, University of Crete
Abstract:
This talk concerns the problem of active array imaging of weak localized scatterers in randomly inhomogeneous media when only intensities are measured. To image we propose a methodology based on cross-correlations, which can be obtained from multiple-frequency intensity only measurements. The cross-correlations are the elements of the time reversal matrix for one receiver and multiple sources emitting at multiple stepped frequencies. We show how the time-reversal matrix can be obtained from intensity only measurements using an appropriate illumination strategy and the polarization identity. Imaging is based on back-propagating the elements of the time reversal matrix that correspond to cross-correlations at nearby frequencies and for nearby sources. A simple linear algebra implementation of the thresholding operation is implemented using a mask, that is a matrix with only zero and one elements. The robustness of our approach is illustrated with several numerical simulations carried out in an optical imaging regime.
