Proc. SPIE. 10836, 2018 International Conference on Image and Video Processing, and Artificial Intelligence
KEYWORDS: Thermography, Signal to noise ratio, Infrared imaging, Detection and tracking algorithms, Video, Field programmable gate arrays, Infrared radiation, Image enhancement, Video processing, Reconstruction algorithms
Due to that the infrared thermal imaging system has the characteristics of low contrast and small dynamic range, this paper proposed an real-time infrared image enhancement algorithm based on Limit Contrast Adaptive Histogram Equalization (CLAHE) and also provided the algorithm implementation. The algorithm firstly divides the pretreated image data into several sub-regions of size, and then the histogram of the sub-region is calculated respectively, the clipping threshold of histogram is determined according to the image gradient information, the captured pixels are evenly distributed to each gray level. Finally, bi-linear interpolation is used to remove the unbalance effect of block edge transition. Experimental results show that compared with traditional algorithms, this algorithm is capable of suppressing the noise and highlight the edges and details of the image, as well as meeting the real-time requirement.
In this paper, the key technologies of single photon detection in airborne laser ranging are analyzed. Aiming at the engineering application, we propose the next investigation of single photon detection. 1) the compensation of pulse propagation in atmosphere; 2) the problem of ranging accuracy for moving targets; 3) high accuracy optical axis coherence of receiving and transmitting. Further research can improve the airborne adaptability of single photon ranging system.
Target Simulator could simulate Infinity Distance Dynamic Target with Optical Characteristics. It provides simulative target for IRST to test its technical indexes of target detecting on the ground. A scheme of Off-axis RC Target Simulator, which has high resolution and Compact Characteristics. This scheme not only could simulate full wave optical Characteristic target of high resolution, but also Use full aperture Light of Compact optical system. The results show that the focal Length is 800mm, the aperture is 130mm, the length is 290mm,the width is 190mm, the height is 190mm, the modulation transfer function of full wave near diffraction-limited , the distortion is less than 2%,and the weight is less than 10kg.
In the field of airborne photoelectric detection, medium wave imaging lenses with large field of view are mainly used for assistant navigation. A new type of optical system of wide field of view is introduced in this paper. It has compact structure, and could match cooling medium wave IR detector with different F numbers. It is proved that the system could realize the large field of view, image illumination uniformity, low distortion, the same resolution in the whole field of view. The structure of the imaging system introduced in this paper provides a reference for the design of medium wave detection system of large field of view of Variable F number.
In this paper, a performance test system is designed, which is used to produce the difference in temperature between the target and the background, and simulate the infinite infrared targets. The medium-wave imaging system detects infrared target and generates target image. The evaluation of the performance of the medium-wave imaging system is completed by using the standard test method and data processing and analysis of images in the laboratory. The test system, which has the field of view of 30°×30°, the focal length of 34mm, and the distortion is less than 3%, could meet the need of testing the temperature sensitivity, resolution and transfer function of the medium-wave imaging system which the field of view is more than 90°.
Laser echo has an important application in target detection and identification, beam quality analysis and so on. In the paper, a receiver for detecting laser echo signal is designed. Combined with the far field target plate, the facula performance test of photoelectric products can be carried out at the outfield experimental station. The laser echo receiving device mainly includes optical system, photoelectric conversion module, signal processing system, data processing and display control system and so on. The optical focal length of receiver is 1299.99mm, caliber 160mm, and image resolution is 320*256. Finally, the correctness of the laser echo receiver is verified by simulation experiments.
Compared with microwave radar, Laser radar has high resolution, strong anti-interference ability and good hiding ability, so it becomes the focus of laser technology engineering application. A large scale Laser radar cross section (LRCS) measurement system is designed and experimentally tested. First, the boundary conditions are measured and the long range laser echo power is estimated according to the actual requirements. The estimation results show that the echo power is greater than the detector's response power. Secondly, a large scale LRCS measurement system is designed according to the demonstration and estimation. The system mainly consists of laser shaping, beam emitting device, laser echo receiving device and integrated control device. Finally, according to the designed lidar cross section measurement system, the scattering cross section of target is simulated and tested. The simulation results are basically the same as the test results, and the correctness of the system is proved.
In order to improve capability of detection, infrared optical system, in a complex electromagnetic environment, is
required to have high sensitivity and dynamic range. The value of dynamic range shows the range of infrared radiation
detected by infrared optical system. The wider dynamic range of infrared optical system, the more objective information
detected, and this helps to analyze and identify targets more. Based on the definition of dynamic range of infrared optical system, a method of testing and data processing of dynamic range is described in detail. And it is proved to be feasible and suitable for testing the dynamic range of infrared optical system with wide Field of View.
Illumination system is one of the most important parts of the micro-lithography object lens. Its performance can greatly
affect the lithography machine's etching graphic quality. In this paper, we discuss a DUV micro-lithography illumination
system which can achieve high uniformity and a large illuminated area on the mask. According to the large numerical
aperture requirement, a refractive illumination system is designed and optimized with software ZEMAX. The system
also meets the requirement of large illumination area on the mask, and no aspherical lens is used. Characters of different
illumination structures and modes are introduced here. Then by using the software of TracePro, illumination systems
with different kinds of aperture are modeling and illuminaces are analyzed. We research effect of illuminace on the mask
which bring by different kinds of aperture. Also in this paper, we make a study of relationship between different
illumination mode and different kinds of graphics. Finally, we compare the results and give suggestion about how to
choose illumination mode. That is meaningful for choosing different aperture in illumination system of microlithography.
In cryogenic infrared optical system, any inner component of this system above absolute zero will emitt infrared
radiation. These radiation, striking detector surface through transmitting in optical system, makes self-stray radiation of
infrared system. This self-stray radiation is dominant stray radiation in cryogenic infrared system, and it is a key factor of
reducing image quality of cryogenic infrared system. How to suppress self-stray radiation becomes a critical work in the
whole design process of cryogenic infrared system. Take a space remote sensor as an example, distribution change of
self-thermal radiation on the detector surface when the space remote sensor under different temperature, emissivity or
surface state is presented in this paper. Phenomena of self-thermal radiation in optical system is also researched from two
aspects of self-radiation of emitting sources and transmission of thermal radiation in optical system. Consequently,
several key factors of making thermal radiation of detector surface change are found. Therefore, corresponding measures
of suppressing thermal radiation are proposed. And self-stray radiation of cryogenic infrared optical system has been
effectively suppressed and the performance of the space remote sensor has been ensured within its technical requirement.
Cryogenic space remote sensor(CSRS), working on the Sun-synchronous orbit, is used to make observation of deep
space and implement scientific research tasks. To observe small targets in deep space, CSRS should have quite low
noise. Stray light is a major part of noise that affects the imaging quality, therefore, stray light control is a critical part of
CSRS. CSRS is cooled to 10K, and works on the orbit which is never directly illuminated by the Sun and far away from
other radiation sources such as the Earth and the Moon, so stray light from these objects can be neglected. This paper
focuses on stray light from self thermal emissions of CSRS components, which plays a more important role in acquiring
qualified image. Based on the theory of radiation energy transfer in the optical system, a method is proposed to
calculate self thermal emission. After analysis of self thermal emission, measures suppressing stray light are put
forward. Also in the paper, a few simulations to testify the scheme mentioned above are presented. Component
emittance and paint absorbance are measured at various wavelengths as inputs for simulations. The results show that peak value of irradiance is well restricted to meet the system's requirement.