Abstract:For various infrared photoelectric detectors operating in the wavelength region from 1 μm to 30 μm, mercury cadmium telluride (MCT) has become the most important semiconductor material. To obtain the best performance, the dark current in the MCT detectors must be minimized. By summarizing and analyzing the related references published in recent years, the progress of the research on MCT dark current is presented and the understanding and comprehension of the dark current in MCT photodiodes are discussed.

Abstract:The research and application of Artificial Neural Network (ANN) in the modeling of near infrared spectrum at home and abroad in recent years are overviewed. The ANN includes back-propagation network, radial-basis function network, support vector machine, self-organizing feature mapping, generalized regression neural network, probabilistic neural network, wavelet neural network, fuzzy network and neural network ensemble etc.. The basic operation principles, advantages and disadvantages of these networks are summarized. Finally, the trend of ANN in near infrared spectrum modeling in the future is proposed according to the development of ANN and the demands in industry and agriculture.

Abstract:A rectangular reflector for a space remote sensor is designed in detail by taking the choice of material, the lightweight of the reflector and the design of the supporting structure into account. The reflector uses a flexible supporting structure which has an open bottom and a low weight triangular reinforced six-point backside structure. The parameters of the flexible supporting structure are determined with a finite element analysis technique. Finally, the dynamic characteristics of a reflector assembly prototype are tested in a mechanical test environment. The test result shows that this structure meets the design requirement.

Abstract:Calibration method is a correction method which is frequently used to correct the nonuniformity of infrared focal plane arrays (IRFPA) at present. The algorithm of this method is simple and can be implemented with hardware easily. However, this method also has a shortage of low correction precision. For this, the actual nonlinear response curves of an IRFPA detector is obtained experimentally. Then, the influence of the number and selection of the calibration points on the nonuniformity correction precision of the IRFPA detector is further analyzed. This work has laid the basis for the improvement of the correction precision of the calibration method.

Abstract:An improved two-dimensional maximum entropy segmentation algorithm for infrared images based on fractal theory was proposed. The algorithm uses the image fractal dimension to excavate the spatial distribution information in image pixels. Then, it combines the original image grayscale with the mapped image grayscale from the fractal dimension to form a two-dimensional random vector and construct its joint probability distribution. On that basis, the two-dimensional maximum entropy principle is used to determine an optimal two-dimensional segmentation threshold and hence to obtain the final segmentation result. The experimental result shows that the improved algorithm is better than the traditional two-dimensional maximum entropy segmentation algorithm in segmentation effectiveness.

Abstract:The concepts and implementation principle of Region, Level of Detail (LOD) and NetworkLink in Keyhole Markup Language (KML) are presented. The method for rapidly loading large image files into Google Earth by using the KML super-overlay files created through KML tags including , and are described in detail. The batch creating of KML super-overlay files based on remote sensing image data is implemented by using VC . The practicality of this technique is verified in a project.