Millimeter-wave Passive Imaging Superresolution Theory And Image Enhancement Algorithm

Passive millimeter wave (PMMW) imaging system is one of the tools to detect this radiant energy and convert it to images. It provides special advantages over the optical and Infra-Red (IR) systems, especially under the poor weather with frog, clouds and mist which are effectively transparent at millimeter wavelength. Due to the reflection of the sky radiation by the metallic, building, road surface and the airstrip, the PMMW images are often acquired with good contrast. Meanwhile, the millimeter wave can partly see through the nonmetallic materials, so it is easy to be hided. Then compared to the active imaging, the passive is more likely to survive on the battlefield. Besides, the passive imaging system is easy to escape from the radar's tracking. Consequently, PMMW imaging system is more and more popularly used and has attracted more concerns. The PMMW imaging technique will be a new research trend in the future.This thesis was completed following the PMMW imaging project, focusing on the research of the PMMW imaging theory and the PMMW images'super resolution and enhancement. In this paper, the research and analysis about the PMMW imaging systems was presented. Then we researched and calculated the ideal imaging process of passive millimeter wave focal plane array imaging systems and proposed the imaging model. Simulations were conducted to verify the imaging model.Due to the higher diffraction in millimeter wave range and the influence by the atmosphere, the PMMW images are often acquired with poor resolution. In order to enhance these images and recover the spatial resolution, super resolution algorithms are often applied. In this paper, we presented the analysis and research on these topics and proposed singular value decomposition (SVD) based linear and nonlinear image enhancement technique for PMMW images. Then these algorithms were applied to the PMMW experiment system and the corresponding results were presented.