Research On Passive Imaging Detection Technology In The Millimeter-Wave Band

Millimeter-wave wavelength is between microwave wavelength and infrared wavelength. In addition, the common characteristics of microwave and infrared, it has other inherent characters. Compared to microwave, millimeter-wave has good directivity, strong anti-jamming ability, and can penetrate plasma etc. Compared to infrared, millimeter-wave is hardly influenced by climatic condition, and can distinguish metal targets from environment around. So, millimeter-wave passive detector is more effective than optoelectronic detector at the conditions of bad weather or battle dust, it can operate under all-weather conditions. Recently, with the development of millimeter-wave solid devices and high speed signal processing technology, the focal plane arrays multi-beam imaging technology with high imaging precision and real-time has been applied to military and civilian gradually, meanwhile, it has become one of the hotspots at present research.In this paper, the domestic and overseas research survey of millimeter-wave passive detection system and radiation measurement theory and techniques are introduced firstly, then studies and development trend of millimeter-wave passive detection technology are explained in recent years, the principle, composing and key techniques of millimeter-wave focal plane imaging system are also analyzed.Secondly, the direct demodulation detection system of 8mm wave band 32-channel on the background of millimeter-wave focal plane imaging is built, according to millimeter-wave passive detection theory, at the same time, the principle experiment is carried out, and the basic theory of millimeter-wave detection are confirmed.Then, the processing methods of imaging result of millimeter-wave passive detection system are mainly discussed, and the wavelet nonlinear extrapolation algorithm is applied to millimeter-wave radiometric image enhancement, furthermore, a super-resolution method based interpolation and improved nonlinear extrapolation algorithm is proposed. As a result, on the one hand, the spatial resolution of millimeter-wave radiometric image is improved; on the other hand, the visual quality...