Research On MMW/SMMW Objects Radiation Characteristic And Detection Technology

The millimeter wave (MMW) passive detection technology is applied in many fields, such as astronomy, remote sensing, military affairs and so on, owing to important practicality and wide potential application. With the application, the research on detection system advances towards higher frequency band, i.e. submillimeter wave (SMMW) band. For the developing of passive detection system of relevant band, the objects radiation characteristics and energy detection in 0.3mm-3mm waveband are studied in the paper.The radiation energy received by detectors includes the energy radiated by objects and reflected from the environment. And the radiation energy transmitted in the atmosphere may be affected by the atmosphere molecules or the hydrometeor, such as rain drops. It's important to analyze objects radiation and atmosphere transmission characteristic before the research on radiation energy detection. So the paper mainly includes four aspects, i.e. objects radiation theories, radiation energy transmission in the atmosphere, objects radiation characteristic modeling and radiation energy detection.On the objects radiation theories aspect, Rayleigh formula is amended based on Planck equation in 0.3mm-3mm waveband. The emissivity and reflectivity of different interfaces are studied. And the differences of radiation characteristic between some normal metal and nonmetal objects are analyzed.On the radiation energy transmission in the atmosphere aspect, the scattering theory and physical characteristic of atmosphere molecules or hydrometeor are analyzed. Based on the absorption and scattering properties of hydrometeor, the attenuation caused by rain drops or else particles in 0.3mm-3mm waveband is studied. The relationship curves of frequency and attenuation coefficient or cross-section are put forward.On the objects radiation characteristic modeling aspect, the calculation method of sky radiation temperature is studied which counts on weather fact. The relationship of physical temperature and radiation temperature is analyzed. Then the vary temperature objects radiation temperature model, i.e. VTRT model, is introduced. Its rationality is validated by the experiment. At the same time, the radiation temperature distribution of a scaled vehicle model is simulated and forecasted by VTRT model.On the radiation energy detection aspect, based on the research of objects radiation and transmission characteristic, the energy detection mode and relevant influencing factors are analyzed. The distance equation of radiometer is amended including the atmosphere attenuation. Then the 360GHz AC total power radiometer is designed. And its relevant parts are chosen and designed.In conclusion, the objects radiation characteristics and detection technology in 0.3mm～3mm waveband roundly from radiation energy generation, transmission and detection are studied in the paper. It provides the theoretical and technical supports for the development of passive detection system in 0.3mm～3mm waveband.