Comparison of speckle reduction diversity tools for active millimeter-wave imaging.
Imaging concealed objects with millimeter-wave coherent radiation is accompanied by speckle. Like all interference phenomena, speckle depends on three light parameters of the millimeter-wave laser beam--phase, wavelength, and angle of incidence--and can be reduced by the diversity of these three parameters. Diversity tools to improve images of concealed objects have been compared. We report measurements, simulations, and image reconstruction results over the whole W-band (75-110 GHz) and demonstrate where each tool works the best. Multiphase diversity is successful in reducing speckle contrast: multiangle to improve the image quality, and multispectral to recognize a small object's features. A simple postprocessing eliminates the areas still covered by interference.
Jaeger
Irina
I
Lab for Micro- and Photonelectronics, Electronics and Information Processing Department, Vrije Universiteit Brussel, Brussels, Belgium. ijager@etro.vub.ac.be
Stiens
Johan
J
Zhang
Lixao
L
Islam
Saiful
S
Koers
Gaetan
G
Vounckx
Roger
R