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179 results on '"Fei, Jindong"'

3. Colorimetric calibration of coupled infrared simulation system

Author

Gao Yang, Fei Jindong, Ying Zhang, and Du Jian

Subjects
Materials science, Infrared, business.industry, Collimator, Astrophysics::Cosmology and Extragalactic Astrophysics, Temperature measurement, law.invention, Filter (large eddy simulation), Optics, law, Black body, Radiance, Calibration, Black-body radiation, Astrophysics::Earth and Planetary Astrophysics, business, Astrophysics::Galaxy Astrophysics, Remote sensing
Abstract

In order to test 2-color infrared sensors, a coupled infrared simulation system can generate radiometric outputs with wavelengths that range from less than 3 microns to more than 12 microns. There are two channels in the coupled simulation system, optically combined by a diachronic beam combiner. Each channel has an infrared blackbody, a filter, a diaphragm, and diaphragm-motors. The system is projected to the sensor under testing by a collimator. This makes it difficult to calibrate the system with only one-band thermal imager. Errors will be caused in the radiance levels measured by the narrow band thermal imager. This paper describes colorimetric temperature measurement techniques that have been developed to perform radiometric calibrations of these infrared simulation systems above. The calibration system consists of two infrared thermal imagers; one is operated at the wavelength range of MW-IR, and the other at the range of LW-IR.

Published
2015

4. Dynamic simulation for distortion image with turbulence atmospheric transmission effects

Author

Zhao Hongming, Chen Cheng, Du Huijie, Yu Hong, Fei Jindong, and Duzheng Qing

Subjects
Physics, Point spread function, Dynamic simulation, Wavefront, Cardinal point, Optics, Pixel, Turbulence, business.industry, Computer Science::Computer Vision and Pattern Recognition, Image processing, Ray tracing (graphics), business
Abstract

The imaging through atmospheric turbulence is an inevitable problem encountered by infrared imaging sensors working in the turbulence atmospheric environment. Before light-rays enter the window of the imaging sensors, the atmospheric turbulence will randomly interfere with the transmission of the light waves came from the objects, causing the distribution of image intensity values on the focal plane to diffuse, the peak value to decrease, the image to get blurred, and the pixels to deviate, and making image identification very difficult. Owing to the fact of the long processing time and that the atmospheric turbulent flow field is unknown and hard to be described by mathematical models, dynamic simulation for distortion Image with turbulence atmospheric transmission effects is much more difficult and challenging in the world. This paper discusses the dynamic simulation for distortion Image of turbulence atmospheric transmission effect. First of all, with the data and the optical transmission model of the turbulence atmospheric, the ray-tracing method is applied to obtain the propagation path of optical ray which propagates through the high-speed turbulent flow field, and then to calculate the OPD from the reference wave to the reconverted wave front and obtain the point spread function (PSF). Secondly, infrared characteristics models of typical scene were established according to the theory of infrared physics and heat conduction, and then the dynamic infrared image was generated by OpenGL. The last step is to obtain the distortion Image with turbulence atmospheric transmission effects .With the data of atmospheric transmission computation, infrared simulation image of every frame was processed according to the theory of image processing and the real-time image simulation, and then the dynamic distortion simulation images with effects of blurring, jitter and shifting were obtained. Above-mentioned simulation method can provide the theoretical bases for recovering the blur images and analyzing the turbulence atmospheric transmission effects.

Published
2013

5. The simulation of turbulence effect based on the technology of optical wavefront control

Author

Bing Dong, Yu Hong, Fei Jindong, Zhao Hongming, Du Huijie, Xinqi Hu, and Du Jian

Subjects
Physics, Wavefront, business.industry, Zernike polynomials, Astrophysics::Instrumentation and Methods for Astrophysics, Physics::Optics, Wavefront sensor, Deformable mirror, Atomic, molecular, and optical physics, Ray tracing (physics), symbols.namesake, Optics, symbols, business, Adaptive optics, Optical path length
Abstract

In the process of high-resolution astronomical observation and space optical mapping, the wavefront aberrations caused by atmosphere turbulence effect lead to reduced resolution of optical imaging sensor. Firstly, on the base of influence of atmosphere turbulence effect for the optical observation system, this paper investigates and analyses the development and technical characteristics of deformable mirror, which is the key device of optical wavefront control technology. In this part, the paper describes the basic principles of wavefront control and measurement using the current production line of deformable mirror, including micro-electromechanical systems (MEMS) deformable mirror which is one of the most promising technology for wavefront modulation and Shack-Hartmann wavefront sensors. Secondly, a new method based on the technology of optical wavefront control and the data of optical path difference (OPD) for simulating the effect of optical transmission induced by turbulence is presented in this paper. The modeling and characteristics of atmosphere turbulence effect applied for optical imagery detector of astronomical observation and space optical mapping has been obtained. Finally, based on the theory model of atmosphere turbulence effects and digital simulation results, a preliminary experiment was done and the results verify the feasibility of the new method. The OPD data corresponding to optical propagation effect through turbulent atmosphere can be achieved by the calculation based on the method of ray-tracing and principle of physical optics. It is a common practice to decompose aberrated wavefronts in series over the Zernike polynomials. These data will be applied to the drive and control of the deformable mirror. This kind of simulation method can be applied to simulate the optical distortions effect, such as the dithering and excursion of light spot, in the space based earth observation with the influence of turbulent atmosphere. With the help of the optical wavefront control technology, the optical sensor and ability of space optical detection system for correcting the target image blurred by turbulence of atmosphere can be tested and evaluated in the laboratory.

Published
2013

6. Application of multiple projector technologies for HWIL simulations

Author

Fei Jindong, Zhang Yi, Yang Zhaowei, Yu Hong, Du Huijie, and Gao Yang

Subjects
Engineering, Resistive touchscreen, InformationSystems_INFORMATIONINTERFACESANDPRESENTATION(e.g.,HCI), business.industry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, GeneralLiterature_MISCELLANEOUS, Digital micromirror device, law.invention, Projector, law, Computer graphics (images), Multi-band device, business, ComputingMethodologies_COMPUTERGRAPHICS
Abstract

IR projectors applied in HWIL simulations are responsible for generating a radiometric output which is similar to the imager output for a real world targets and background in desired wavelength to the seeker under test. Projector technologies meet more challenge as seekers performances improving. A variety of projectors has been constructed to satisfy different use. This paper describes three projectors which include a dual-band IR extended source projector, a MWIR Digital Micromirror Device(DMD) projector and a LWIR resistive array projector.

Published
2011

7. The research of non-uniformity correction technologies for resistor array dynamic infrared scene projector

Author

Zhao Hongming, Zhang Yi, Du Huijie, Fei Jindong, and Yu Hong

Subjects
Infrared image, Simulation test, Infrared, Computer science, business.industry, Fixed-pattern noise, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, law.invention, Projector, Projection system, law, Electronic engineering, Radiance, Computer vision, Artificial intelligence, Resistor, business
Abstract

The resistor array devices are commonly used to produce dynamic two dimensional infrared images in the infrared scene projectors. A non-uniformity caused by many factors is the main source of image fixed pattern noise of the projectors based on resistor array devices. A prior non-uniformity correction procedure must be done before the dynamic infrared image generation for the hardware-in-the-loop simulation test and evaluation. In this paper, the developments and details of the non-uniformity correction technologies for resistor array dynamic infrared scene projector are investigated. The research is commenced directed towards understanding the cause of spatially-distributed radiance non-uniformities of resistor array device, and the fundamental elements that underlie the non-uniformity correction technologies in dynamic infrared scene projection system.

Published
2011

39. Overview of the Chinese lidar satellite development

Author

Lv, Yueguang, Bao, Weimin, Chen, Weibiao, Shi, Zelin, Su, Jianzhong, Fei, Jindong, Gong, Wei, Han, Shensheng, Jin, Weiqi, Yang, Jian, Zhang, Xinwei, Dai, Jun, He, Tao, Zhao, Chenguang, Huang, Jin, Li, Xu, Huang, Genghua, and Cao, Haiyi

Published
2017
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