Research

Thrust R1

Subsurface Sensing & Modeling

Subsurface Sensing and Modeling explores the physics of promising new non-linear and multi-modal subsurface probes and develops accurate, efficient, wave-based forward modeling algorithms. These models are essential to the understanding of new subsurface probes and form the basis of the Thrust 2 inverse methods. The research thrust is divided into two areas:

Nonlinear & Dual Wave Probes investigates the fundamental physical mechanisms involved in subsurface imaging and the development of new imaging modalities. A principal theme of research is the use of multiple interacting probes of either the same physical nature (e.g., electromagnetic waves of different wavelengths), or of different nature (e.g., an acoustic wave and an optical wave). These probes may be independent or coupled through some physical interaction.

Nanoscale Imaging is based on broadband optical interferometry. Entangled-photon Sensing and Imaging is another imaging modality using two optical probe waves. Imaging with two interactive waves of different physical nature has also been pursued; a Gordon Center team (Dual-Wave Methods for Biomedical Imaging: Acousto-Optic and Opto-Acoustic Imaging) uses a diffuse optical wave and an ultrasonic wave, interacting in an optically scattering medium, to obtain enhanced diffuse-optical tomography images as well as images of opto-mechanical properties. Development of High-Resolution THz Imaging Systems aims to use terahertz imaging for non-destructive evaluation of the local properties of semiconductor material.

Effective Forward Models investigates models that can be used to advance fundamental understanding and as tools for engineering design, analysis and optimization. Research addresses the barriers that limit rapid, real-time analysis and inversion and serves as the bridge between Thrust 1 and Thrust 2, generating simulated data for a fixed sensor configuration and serving as an integral part of the reconstruction algorithms in:

• ground penetrating radar propagation through rough surfaces, modeling of large collections of weak scatterers such as mitochondria in cells, simulation of the effects of inhomogeneities, rough layers, frequency-dependent dispersive media, and sensor/media coupling (Wave-Based Computational Modeling for Detection of Tumors, Buried Objects and Subcellular Structures).
• elasticity imaging of inclusions imbedded in soft tissue (Biomechanical Imaging).

For more information on Thrust 1, please contact Thrust Leader Carey Rappaport at rappaport@ece.neu.edu.