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浏览/检索结果: 共3条，第1-3条 帮助 限定条件 专题：长春光学精密机械与物理研究所    第一署名单位    第一作者单位    通讯作者单位     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Level 0 and level 1 data processing for a type of hyper-spectral imager (EI CONFERENCE) 会议论文 2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 21, 2009, Shanghai, China Li X.; Yan C. 收藏  |  浏览/下载：62/0  |  提交时间：2013/03/25 Hyper-spectral imaging (HSI) is a kind of optical remote sensor that can simultaneously obtain spatial and spectral information of ground targets. We are now designing a data processing system for a type of space-borne push-broom HSI  then it performs radiometric and spectral calibration based on the ground calibration results and onboard calibration collection. The detailed algorithms for bad pixel replacement  which has 128 spectral channels covering the spectral range from 400nm to 2500nm. With its large amount of spectral channels  radiometric and spectral calibration were presented. After processing  the HSI collects large volume of spectral imaging data need to be efficiently and accurately processed and calibrated. In this paper  the digital numbers downlinked from the spacecraft can be converted into at-sensor absolute spectral radiance of ground targets  the detailed Level 0 and Level 1 data processing steps for the HSI were presented. The Level 0 processing refers to a set of tasks performed on the data downlinked from the spacecraft  thus providing accurate quantified spectral imaging data for various applications. 2009 SPIE.  including decoding to extract science data  separating the science data into files corresponding to different tasks (e.g. ground imaging  dark imaging  and onboard calibration)  checking data integrity and instrument settings  data format conversion  and Level 0 files creation. The Level 1 processing performs several steps on Level 0 data. Firstly  it corrects the image artifacts (mostly the SWIR smear effect)  subtracts the dark background  and performs the bad pixel replacement according to the prelaunch measurement   Rigorous vector analysis of diffractive microlens by using of finitedifference time-domain method (EI CONFERENCE) 会议论文 2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China Liu Y.; Liu H. 收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25 We use finite difference time domain (FDFD) method as rigorous vector analysis model to simulate the focusing process of diffractive microlens (DML). Differing with most analysis model which the near field distributions are calculated by FDTD and then far field are obtained by using of propagation method  we obtain the fields in whole computational space by using of FDTD only. The advantages are that all the results are vector based and the computational time is saved greatly. In this paper  we present two methods to obtain wave amplitude  one is comparison method  and the other is integral method. Depending on wave amplitude in the whole computational space  one can conveniently obtain distributions of electric field intensity and calculate the time-average Poynting vector. We also present the formulation for calculating diffractive efficiency of DML based on time-average Poynting vector which denotes energy flow. As demonstration  a DML is analyzed by using of these algorithms. The time depended graphic results of FDTD show the process of wave propagation. The distribution of electric field intensity illustrates the focusing of the normal incident light. The focus pattern in the focal plane is also show. The diffractive efficiency of the DML is calculated by using of the energy flow method in this paper. The results show the high accuracy and efficiency of the model. 2009 SPIE.   Dome design and coupled thermal-mechanical analysis of supersonic missile (EI CONFERENCE) 会议论文 2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China Xing-qiao A.; Qun W.; Hong-guang J. 收藏  |  浏览/下载：40/0  |  提交时间：2013/03/25 A review of high-speed flow pressure and aerodynamic heating effect on Supersonic missile's dome is given. The dome should have excellent properties in optical  mechanical and chemical characteristics. A design of dome on supersonic mode is described according to tactical guide line of a missile. The dome made of quartz which is about 8mm thick and 141mm in window diameter. To check up the reliability of the dome  a reasonable finite element model (FEM) of dome is established  and a thermal-mechanical Analysis to the dome by finite element software NASTRAN has carried on  through these can obtained the distribution of temperature field and stress field when the speed is 2.3Ma. The results indicated that the stress was concentrated in the joint of the dome end and the Missile Section  and the maximum stress was 16.4Mpa. The stress of other nodes was smaller than the allowable stress of quartz glass. Reference to the results of the analysis  a lightweight revision to the dome structural dimension and a new method of dome fixing have put forward  which can reduce the stress concentration. 2009 SPIE.