Abstract:The atmospheric background is analyzed and the atmospheric radiation intensity and transmittance at different pitch angles are calculated. By analyzing the radiation principle of a high dynamic target in atmosphere, both the calculation model of the infrared characteristics of the target affected by high temperature gas and the calculation result of the infrared radiation intensity of the target in different wavebands are given. The Signal to Clutter Ratio (SCR) and detection range are calculated by formulas and are analyzed. Finally, the conclusion that the detecting ability is limited is reached.

Abstract:Chemical-mechanical polishing is one of the key surface treatment processes for CdZnTe crystal. The chemical-mechanical slurry is an important factor affecting the surface quality of CdZnTe wafers. At present, most of the polishing slurry for CdZnTe wafers in our country is imported from foreign countries. This has greatly hampered the development of CdZnTe crystals of our country. In this paper, the alkaline chemical-mechanical slurry is prepared by using silica solution and NaClO as the main raw materials. Then, the slurry is used to polish the surface of CdZnTe wafers. The characterization result shows that the polished surface has its roughness less than 2 nm and the slurry can be used to treat the surface of CdZnTe wafers with high quality

Abstract:A real-time infrared image displaying system based on Camera Link is designed for an infrared camera. The analog signal from an infrared detector is converted to the digital one in an analog to digital converter. As a control core, the FPGA is used to process the signal and transmit it remotely via optical fibers. Then, the FPGA at the receiving terminal is used to convert the signal to the Camera Link protocol data and transmit it to the image collection card of the computer for data collection and conversion. Finally, the image data is displayed via the software in the computer.

Abstract:A 10-bit ramp generator for column-level Analog-to-Digital Converter (ADC) circuits of CMOS image sensors is designed. The integral structure, operation mode and simulation result of the circuit is presented in detail. In the circuit, a two-stage conversion mode is used and a resistor-array ramp generator is designed. The circuit design, simulation and layout design are achieved on the platform of Cadence. The proposed ramp generator is taped out in an 0.5 μm DPTM CMOS process. The simulation result shows that this design meets the related requirements basically.

Abstract:An infrared target extraction algorithm based on the energy of a target is proposed. By utilizing the phenomenon that the image may smear when the relative angular velocity of a target exceeds the instantaneous field of view, the algorithm enhances the signal-to-noise ratio of the target and background through energy accumulation. Thus, a remote infrared target with the signal-to-noise ratio less than or equal to 5 can be detected and tracked. The algorithm has a small computation amount and is easy to be implemented on hardware. The experimental result shows that this algorithm can detect and track an infrared target which is 15 kilometers away with a detection probability of 96%.

Abstract:Although the least square method is widely used in the calibration of infrared thermal cameras at present, its accuracy is not ideal. To reduce the influences of the system random error, environmental fluctuation and unstable blackbody temperature of a thermal camera on the calibration result, a calibration model for infrared thermal cameras based on a weighted least square method is established. Both calibration experiments and radiation measurement experiments are carried out by the weighted least square method and the least square method respectively. The experimental results show that the calibration model based on the weighted least square has a higher fitting accuracy and its mean measurement accuracy in radiation measurement experiments is improved by 2.3% compared with that of the least square method. The calibration based on the weighted least square method is of practical value and of a certain referential significance.

Abstract:Soil is the foundation for human survival, the most important environmental information reflected in earth remote sensing images and also the basis for studying other environmental elements. So, it is of great significance to study the characteristics of soil. At present, there has been a few studies of the polarized thermal radiation characteristics of soil in 2π space. In this paper, the polarized radiance of soil is measured. The result shows that the polarized radiance of different soil types is different at different detection angles. At the detection angle of 60°, the study of the polarized radiance of soil is more effective. With the change of the azimuth angle, the polarized radiance of soil will change. In the range from 0° to 60°, the polarized radiance of soil has a rising trend with the increase of the azimuth angle. But in the range from 240° to 320°, the polarized radiance of soil has a declining trend. The change of the detection band will cause the polarized radiance of soil to be changed. The order is CH1>CH4>CH4>CH2. The polarizing angle has a certain influence on the polarized radiance of soil too, but the fluctuation amplitude is gentle. For different soil types, the polarized radiance is different and the response to different factors is also different.

Abstract:The influence of work function of transparent conductive oxide on the performance of μc-Si(n)/c-Si(p) heterojunction solar cells is analyzed by using a AFORS-HET software. The simulation results show that the work function of transparent conductive oxide has a great influence on the performance of solar cells, such as Voc and FF. When the work function of transparent conductive oxide at the interface of TCO/μc-Si:H(n) is less than 4.3 eV, the thickness of μc-Si:H(n) emitting layer is 6 nm, the work function of transparent conductive oxide at the interface of μc-Si:H(n) /TCO is greater than 5.2 eV and the transparent conductive oxide is ZnO, the TCO/μc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/μc-Si:H(p )/TCO solar cell has its photoelectric conversion efficiency up to 23.78% (VOC:758.6 mV, Jsc:40.94 mA/cm2, FF:76.58%). The result shows that the performance of the μc-Si:H(n)/c-Si(p) heterojunction solar cell is closely correlated with the work function of transparent conductive oxide. Through the work function of transparent conductive oxide, the efficiency of solar cells can be improved.

Abstract:Taking the real Zu Yeqing tea produced in Leshan, the inferior Zu Yeqing tea and the Maofeng tea produced in Emei Mountain as the research objects, a classification algorithm for different kinds of tea based on near infrared spectroscopy is put forward. The algorithm uses Multiplicative Scatter Correction (MSC) to preprocess the near infrared spectral data of the above three kinds of tea for removing the random variation in the spectral data maximally. Then, it uses Principal Component Analysis (PCA) to reduce the dimensionality of the spectral data for removing redundant. Next, it carries out Linear Discriminant Analysis (LDA) for further feature extraction. Finally, it uses the K_Nearest Neighbor algorithm to classify the first features in the LDA result so as to realize the qualitative tea classification. The experimental results show that this algorithm can classify the above three kinds of tea effectively. Its correct recognition rate is up to 100%. This study provides a new idea for the classification of tea.