Spatially Multiplexed Optical MIMO Imaging System in Cloudy Turbulent Atmosphere

摘要

Active optical imaging is preferred over Radio Frequency (RF) counterparts due to its higher resolution, faster area search rate, and relatively easier interpretation by a human observer. However, in imaging through atmosphere one should consider dispersive effects of multiple scatterings and turbulence-induced wave perturbations, which give rise to intensity fluctuations, and wave-front distortions. All these phenomena broaden and distort the spatial impulse response known as the Point Spread Function (PSF). In this paper, a multiplexed Multi-Input Multi-Output (MIMO) imaging system design is introduced. At the transmitter, a computer generated holographic beam-splitter is used to generate arrays of beamlets, providing faster area search rate and a uniformly distributed illumination all over the target. Then at the receiver, an array of photo-detectors is used to collect the reflected rays. While a Monte-Carlo Ray Tracing (MCRT) algorithm, developed at Pennsylvania State University, Center for Information and Communications Research (CICTR), is used to model imaging in multiple scattering turbid media, phase-screens are employed to simulate turbulence-induced wave-front distortions. Hence, a comprehensive frame work is exploited that takes into account possible sources of degradation. Using this frame of work, system performance is analyzed under different meteorological conditions and restoration techniques such as Blind Deconvolution (BD) are used to retrieve the original image by deconvolving PSF and observed image.