Sensing and imaging in scattering media using spatial speckle intensity correlations and field statistics in heavily scattering media

Jason A Newman, Purdue University

Abstract

Coherent imaging through or within heavily scattering random media has been considered impossible due to the randomization of the information contained in the scattered field. This randomization results in speckled images, with no apparent in- formation about the object of interest. Through the use of spatial speckle correlations over incident field position, the field incident on a heavily scattering random medium can be reconstructed, effectively allowing us to see and communicate through opaque heavily scattering materials. This correlation method is developed further to provide a theory and method for sensing and imaging moving objects hidden within heavily scattering random media. Even if an object is embedded within an opaque material and is effectively hidden, its movement alone is enough to reveal it to an observer. These speckle correlation methods provide new avenues for sensing, imaging, and communicating in traditionally problematic environments. The field statistics for strongly scattering media, where Gaussian statistics no longer hold, are presented. A circular Bessel density function, derived from the K-distribution for intensity, is used to describe the electromagnetic field statistics in the Anderson localization regime. Numerical terahertz field data is used to demonstrate the validity and applicability of the circular Bessel density function. These field statistics provide a framework for improved understanding of wave propagation in and near the Anderson localization regime.

Degree

Ph.D.

Advisors

Webb, Purdue University.

Subject Area

Computer Engineering|Electrical engineering|Computer science

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