Research On Short Millimeter Wave Near Range Active And Passive Array Detection And Imaging

Short millimeter wave (SMMW), which frequency is 100-1000GHz and wavelength is 3mm-0.3mm, has the advantages of microwave and infrared. It has some ability to penetration while retaining high resolution. The objects with different physical properties can be distinguished according to their scattering or radiation energy. So currently, SMMW near range object detection and imaging is a very important development direction. SMMW passive imaging has a capability with all-time and all-weather, the geometric shape, texture, temperature and other characteristics of the object can be obtained. The three-dimensional stereoscopic image of the object can be obtained in active imaging, and the effect is more ideal. If two imaging methods are combined, which learn from each other, more comprehensive and detailed information can be obtained about the object. The priori conditions can be provided for object detection and identification. At the same time, the extensive application about SMMW near range detection and imaging technology can be promoted in medical, navigation, traffic control, public safety and other areas.Three aspects are studied in this paper, which are SMMW near range object scattering and active imaging technology, SMMW near range object radiation and passive imaging technology, active and passive combined array imaging technology.The research work is as follows:(1) SMMW transmission characteristics are analyzed in sunny weather, including the atmospheric absorption, refraction, scattering and attenuation. The research focus is SMMW transmission characteristics in the rain. The model is established about raindrop attenuation cross-section, and the rainfall attenuation curves are obtained in SMMW frequencies. SMMW transmission characteristics are analyzed briefly in the clouds and fog. Finally the special transmission characteristics and application are discussed in SMMW non-atmosphere window frequencies.(2) The research on near range object scattering is impacted by glint effect. To reduce the effect, a wave number domain phase compensation method is proposed. And the experiment results are consistent with the object characteristics, showing the method is effectively. To realize the objective space scattering characteristics distribution roundly, the study of SMMW near range object scattering imaging is launched. The principle of scattering imaging is expounded, and three imaging algorithms for different shape objects are advanced. Finally, the imaging system design and test methods are discussed, and the reference is provided for engineering realization of the system.(3) According to the characteristics of SMMW object radiation, the modeling, calculation and analysis of SMMW object radiation are carried out. By means of microwave and infrared, the law of SMMW radiation is revealed at different frequency and temperature. Further SMMW passive array imaging principle and system design are analyzed, and the researche focus is imaging features and image restoration methods.(4) The principle and key parameters are analyzed about SMMW active and passive combined array imaging system. The engineering research is carried out about SMMW active and passive combined array detection system. To key components, signal processing hardware and software implementation of the system, it has a detailed analysis. In the end, some outdoor experiments are done with a successfully developed prototype, and the results are analyzed.Summary, the researches are carried out about SMMW near range object active and passive array detection and imaging technology. The theory, algorithm, system construction and other aspects are studied intensively about active scattering and imaging, passive radiation and imaging, active and passive combined detection and imaging, all that promote the development of SMMW near range active and passive detection and imaging technology.