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	Estimation of the Grassland Aboveground Biomass of the Inner Mongolia Plateau Using the Simulated Spectra of Sentinel-2 Images 期刊论文 OAI收割 REMOTE SENSING, 2020, 卷号: 12, 期号: 24, 页码: 22 作者: Pang, Haiyang; Zhang, Aiwu; Kang, Xiaoyan; He, Nianpeng; Dong, Gang \| 收藏 \| 浏览/下载：28/0 \| 提交时间：2021/03/15 aboveground biomass multispectrum hyperspectral Sentinel-2 the simulated spectrum estimation
	Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT 期刊论文 OAI收割 Astrophysics and Space Science, 2020, 卷号: 365, 页码: 158 作者: HXMT \| 收藏 \| 浏览/下载：49/0 \| 提交时间：2022/02/08 Insight-HXMT Geant4 simulation Background observation Astrophysics - Instrumentation and Methods for Astrophysics Abstract: Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, in-orbit backgrounds of these three telescopes had been estimated through Geant4 simulation, in order to investigate the instrument performance and the achievement of scientific goals. In this work, these simulated backgrounds are compared with in-orbit observations. Good agreements are shown for all three telescopes. For HE, (1) the deviation of the simulated background rate after two years of operation in space is 5 % from the observation (2) the total background spectrum and the relative abundance of the 67 keV line show long-term increases both in simulations and observations. For ME, (1) the deviation of simulated background rate is within 15 % from the observation, and (2) there are no obvious long-term increase features in the background spectra of simulations and observations. For LE, the background level given by simulations is also consistent with observations. The consistencies of these comparisons validate that the Insight-HXMT mass model, i.e., space environment components and models adopted, physics processes selected, and detector constructions built, is reasonable. However, the line features at 7.5 and 8.0 keV, which are obvious in the observed spectra of LE, are not evident in simulations. This might result from uncertainties in the LE constructions.
	Micro assembled fourier transform spectrometer (EI CONFERENCE) 会议论文 OAI收割 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China 作者: Liang J.-Q.; Zhang J.; Zhang J.; Zhang J.; Wang B. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 With the trend of minimization of Fourier transform spectrometer (FTS) which is particularly pronounced in many applications a model of a micro FTS with no moving parts is proposed and analyzed. During analyzng the gradients which mainly introduce phase error are accounted. Based on these assumptions and the improved Mertz phase correcting method the spectrum of signal is simulated with real extended light source. The resolution can be up to 3.43nm@800nm with high signal-to-noise ratio (SNR) limiting resolving ability 6.8dB. In addition the fabrication method of components are illuminated and demonstrated which can not only make it bear some advantages over conventional micro dispersive spectrometers but also afford some new concepts on the design of spectrometers with improved performance. 2009 SPIE.
	Analysis of spectrum narrowing of diode laser bar (EI CONFERENCE) 会议论文 OAI收割 Semiconductor Lasers and Applications III, November 12, 2007 - November 13, 2007, Beijing, China 作者: Liu Y.; Wang L.; Wang L.; Wang L.; Liu Y. 收藏 \| 浏览/下载：18/0 \| 提交时间：2013/03/25 Laser diode bar (LDB) are used increasingly often for many applications but spectral bandwidth of LDB are generally approximately 2-4nm far too wide for many demanding applications e.g. spin-exchange optical pumping terahertz generation and lidar. External-cavity feedback can improve the spectral properties of LD or LDB. However spectrum narrowing of LDB is more difficult than that of LD. Bar curvature (i.e. "smile") produced in the manufacturing process affects the spectrum narrowing greatly. By geometrical optics approach and ORIGIN software smile which can be corrected by plano-convex cylindrical lens is simulated and the result is in good agreement with experiment. The selection of grating which is also a critical factor of spectrum narrowing will be stated. Finally an external cavity consisting of fast axis collimator two plano-convex cylindrical lens and a diffraction grating is used. The scheme is implemented on a 19-element LDB and yields 3-fold reduction in spectral linewidth under the situation that all optical elements in the system which are not optimized. Further we use a slit in the experiment and analyze the spectrum narrowing of each element in LDB.
	Design of a scene simulator in land-based aerospace lab with the man-made light source system based on quantum theory (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Devices and Integration II, November 12, 2007 - November 15, 2007, Beijing, China 作者: Fang W.; Yi W. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 The paper presents a method with the technique of combination filtering of spectrum and the technique of DSP control for the simulation and recognition of the spontaneously lightening object and stellar map in the universe. The magnitude and the spectrum of a star can be simulated in a wide dynamic range. We established the mathematical models of the Vega's visible light spectrum and luminous flux density. Tungsten-halogen lamp as a light source is used to fit the linear light of the spontaneously lightening object in the universe. Through the experiment it shows that the more sub-channels there are while filtering spectrum in the visible spectrum and the more degrees the variable neutral density filters and the narrow-band attenuators have more close to the actual spectrum the simulated spectrum is. It is proved that using the PID technique is beneficial to the output of the accurate and steady radiation from the light sources. The experiment shows that the using of this method can get perfect result in fitting and simulating the spectrum magnitude and the stellar map of the spontaneously lightening object . The analysis of the consistent result and the experimental error is also discussed in detail in this paper.
	Numerical simulation and experiment of novel semiconductor/superlattice distributed Bragg reflectors (EI CONFERENCE) 会议论文 OAI收割 Optical Transmission, Switching, and Subsystems III, November 7, 2005 - November 10, 2005, Shanghai, China 作者: Zhao Y.; Zhao Y.; Zhao Y.; Wang X.; Wang X. 收藏 \| 浏览/下载：16/0 \| 提交时间：2013/03/25 We introduced a novel semiconductor/superlattice AlAs/(GaAs/AlAs) distributed Bragg reflector (DBR) and the reflection spectrum of the DBR at 980nm wavelength is simulated by employing transfer matrix method. By adjusting the thickness of AlAs layer and the period of superlattice GaAs/AlAs the DBR with center wavelength at 1500nm is also investigated theoretically. In experiment this kind of DBR is grown on GaAs (100) substrate. From the measured reflection spectrum the central wavelength is about 980 nm with high reflectivity.