Abstract:High definition infrared imaging systems are those thermal imagers that have higher spatial resolution without sacrificing thermal sensitivity and generate video signals according to the high definition television standards (1280?1024, 1920?1080 or 1280?720). The higher the spatial resolution is, the smaller the detectable target is and the farther the target is from. The improvement of spatial resolution means that the number of detector pixels is increased, the pixel pitch is decreased and the signal-to-noise ratio in each pixel is enhanced. Digitization involves the incorporation of an analog-to-digital converter (ADC) into a readout integrated circuit (ROIC). Analog-to-digital conversion can be implemented with a high speed ADC at the chip level or be implemented with multiple medium speed ADCs at the column level or be implemented with multiple low speed ADCs at the pixel level. Because only digital data need to be transferred, the ADC at the pixel level is helpful to the reduction of system noise and is suited for implementation in the standard digital CMOS process. The recent advances and trends of infrared imaging systems in the aspects of high definition and digitization are presented.

Abstract:Factors resulting in vacuum failure are analyzed. The influence of leakage on the vacuum lifetime of a Dewar can be controlled strictly by using an ultrahigh sensitivity leakage detection technology. The outgassing decline characteristics in the vacuum jacket are described by using the outgassing model in the form of power i.e. q(t)=q₀(t/t₀)_-α. The vacuum decline process in the vacuum jacket of the Dewar can be accelerated by means of temperature. The influence of temperature on the outgassing rate of material is described by using the Arrhenius model q=q₀exp(-E/RT). The acceleration factor can be determined according to the results of theoretical analysis and outgassing experiment.

Abstract:As an emerging non-destructive detection technology, infrared fault diagnosis is developed rapidly in recent years. Compared with the traditional methods, infrared fault diagnosis has a series of advantages such as noncontact and high sensitivity. It is being widely used in the field of fault diagnosis. For the quantitative detection of defects, people has proposed many different methods and established the theoretical model for determining the relation of the defect size to its brightness in infrared thermal images. Each method has its shortcomings and limitation. There is still no a common theoretical model for the quantitative detection of different defects so far.

Abstract:Hyperion images have the features of high spectral resolution , large quantity of data, strong correlation among adjacent bands and high information redundancy. These features have brought many problems to the data processing and interpretation of them. To solve these problems, an idea of band selection and dimensionality reduction by combining the segmented principal component analysis with the band index algorithm is proposed. The adaptive band selection method, band index method and cumulative contribution rate method are used to carry out a comparative study in band selection. The results obtained by four band selection methods are analyzed in optimal band combination, feature reparability and image transformation. The experimental results show that the segmented principal component analysis and band index algorithm can not only restrain the phenomenon that some local important spectra may be filtered due to the global transformation, but also can take into account the adaptive partition subinterval correlation among the bands and effectively reduce the hyperspectral data dimension. The method is better than the traditional adaptive band selection method, band index method and cumulative contribution rate method in band selection.

Abstract:Starting from the characteristics and application status of infrared hyper-spectral data, the influences of different cloud amount, cloud height and water content on the observed spectra under different cloudy conditions are studied according to the minimum vector deviation theory of the observed spectra and background spectra under clear sky conditions. Then, a new method for detecting cloud in infrared hyper-spectral data is proposed. The channels which are not affected by cloud are detected in the cloud-polluted field of view. The feasibility and validity of the method are verified by using both the AIRS's data simulated by a RTTOV model and the measured data. The result shows that this method can effectively improve the utilization of infrared hyper-spectral data in cloud-polluted areas and can provide an effective approach to the inversion of atmospheric parameters under cloudy conditions.

Abstract:A high-voltage power driver for ultraviolet flame sensors is designed. Its operation principle is studied and explained. Finally, the related experimental results of the designed prototype are presented. The power driver operates in the mode of ``hiccup''. It has the features of simple structure and high step-up ratio and can meet the requirement of high operation voltage of flame sensors. Therefore, it is suitable for many small optoelectronic sensors.

Abstract:The methods for detecting small infrared targets in the case of noise and background interference are analyzed. A small infrared target detection algorithm which combines the cycle spinning contourlet transform with the adaptive threshold segmentation is proposed. Firstly, the method uses the cycle spinning to de-noise the original images. Secondly, it obtains the residual images by subtracting the de-noised image from the original image. Thirdly, it uses the adaptive threshold segmentation to segment the residual images so as to separate a few of candidate target points. Finally, it uses the continuity and consistency of target motion to detect the target. The simulation result shows that the proposed detection method can detect the small infrared targets in the sequential images precisely and it is more effective than the Contourlet transform and wavelet transform methods in detection.

Abstract:Three-dimensional physical and mathematic models are established for the internal heat transfer in a defective furnace. The temperature distribution and infrared characteristics of the surface when the defect in a furnace is detected in different positions are studied. The analysis result shows that the firebricks play a major role in the thermal insulation of the furnace. When the firebricks break down, the temperature of the outer surface of the furnace is abnormal. In the position of the defect, the difference between the maximum temperature and the normal operation temperature increases exponentially with the defect depth.