This project will investigate the feasibility of adapting novel microwave imaging hardware and software to permit quasi-real time monitoring and control of micro- or millimeter, wave-penetrable aerospace and commercial materials during their design, development, processing, and operational use. The innovation adapts modulated scattering arrays as multi-point sensors to provide rapid Nyquist-sampled mappings of the materi- al's local reflection and transmission coefficients. These measured data are then used in advanced microwave imaging algorithms based on diffraction tomography (DT) and the electric field integral equation (EFIE) to image equivalent currents, complex permittivity and field distributions. Resolutions of (1/2)Ï and (1/10)Ï in the material are achieved for DT and EFIE imaging, respectively. These microwave imaging techniques directly determine electromagnetic performance. They can also be used to detect and identify many types of material structural defects.
Potential Commercial Applications:Potential commercial applications include imaging of knots and other defects in wood; delaminations in paper products; aircraft, boat, and vehicle composites; control of microwave drying processes; detection of concrete reinforcing bars; detection of drugs and weapons caches; and monitoring of deep hyperthermia treatments
