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Issue 3 ， 2000
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Method of coordinate transformation for IM & IMC calculation in aerospace camera system
Abstract：As the resolving power of aerospace photography is demanded to be higher, the precision of IMC(Image Motion Compensation)system must be higher. For this reason, the sources for inducing image motion need to be considered more comprehensively. Namely, the measurement precision for all factors that affect the IM and the calculating modle for IM should be more accurate. In this paper, the coordiante transform methods were used to calculate the IMC of aerospace camera system. Firstly, the theory, the technical ways and the methods for realizing IMC in aerospace camera system were concluded ; Secondly, in form of homogeneous matrix, all the coordinate transformation were summed up, from which all the basic parts of IMC mathematics calculation model were realized and a general mathematics model for calculating IMC was put forward; Thirdly, the calculation of IMC using coordinate transform methods were expatiated. Finally, the methods of simplifying the vector expression of IM velocity and calculating the error of IMC were discussed birefly, so as to obtain the precise and simplified expressions of IM velocity and error estimation of IMC. Through changing the four parts of the calculation model, the method can be applied to IMC systems of all sorts of aerospace cameras.Keywords：coordinate transform methods;IMC;aerospace camera system- 65
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Published：2020-08-12 -
Star image simulation software of star-tracker
Abstract：Star tracker is a high accurate attitude measuring instrument used in various spacecrafts. The operation process of the star tracker consists of stars imaging on focal plane through optical lens, star light-to-charge conversion with a CCD sensor, preprocessing of star signal for eliminating noise, centroid calculation with sub-pixel algorithms, and at last the attitude computing and coordination conversion. In this paper, the operation process simulation is implemented except the attitude computing. Some simulation results are given in the paper. The method used in the paper is useful for evaluation of star tracker performance. This software can be used in both various space sensors development and astronomical research. But, if it is used in astronomical research, atmospheric effect must be taken into account.Keywords：star-tracker;star image;simulation- 56
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Published：2020-08-12 -
Optical assembly of CCD focal plane for space camera
Abstract：In order to apply space camera to the measurement in large field of view and high resolution, the technique of optical assembly with several CCDs is discussed. Its principle,methods of adjusting and testing as well as the structure of focal plane are described. The assembly with three TDI CCDs is finished on the facility which is composed of a long work-distance microscope and a precise X-Y rail, using the method in which the beam-spliter and the mechanical adjusting are applied. The measuring error is less than one third pixel,the optical assembly has the advantages of simple constitution,low cost and good adaptability.Keywords：optical assembly;focal plane;TDI CCD- 107
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Published：2020-08-12 -
Method for star identification using connection cluster
Abstract：The most accurate instrument for satellite attitude determination is star tracker now, in which the key problem is the identification of star map. In this paper, cluster match is performed only with the observed star position information and using the star angular distance between observed star map and guide star catalog, then match identification is made with respect to the connection of the observed star map, at last, utilizing the computer(main frequency 120M)simulation the effects of threshold and position noise on identification and identification time are analyzed. When the threshold is 0.05°,position noise δ is less than 0.02°, in any areas, the identification efficiency is 100%, and the average identification time is less than 0.2s.Keywords：star tracker;star identification;connection;cluster- 64
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Published：2020-08-12 -
Quality control after matching or image using constraint of epipolar line bunch
Abstract：It is ineluctable in stereo vision that a large numbers of error matched pixel will be present. The quality control after matching is a general method for detecting error matched pixel. This paper described a method for further improving the veracity of matching. A constraint of epipolar line bunch based on Radial Geometry and continuity suppose was given to detect the similar matched pixel and weed out the error pixel by using correlative information of the pixel. The experiment proved that the constraint has better ability for weeding out error pixel. It increased the veracity of matching.Keywords：quality control;image matching;radial geometry;epipolar line- 76
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Published：2020-08-12 -
Optical-wavelet transform application in image processing
Abstract：The image is divided up several subsegments in space for process of aim. With characteristics of domains and multiresolution of Wavelet function, subsegments which have meassages of aim are processed with Optical-Wavelet Transform and the function of Wavelet Transform which have messages of aim are performed with multicenter at the same time. It avoids the mathematical operation which is heavy and complicated, and the speed of image processing is improved. Objects features are given quickly and accurately. The method that edge of image is extracted by means of one-dimensional Optical-Wavelet Transform is described in this paper. The image is divided up many subsegments by means of optics. On the basis of the characteristic of Wavelet function, the image information is processed by Optic-Wavelet Transform in the subsegment. The edge information of the image is picked up in many optic channels at the same time. On the basis of the theory of Wavelet Transform, the principle of Optic Wavelet Transform is expounded in the paper. A suit of the integrate experimental system of Optic-Wavelet Transform is built, the experimental data with theoretical foundation is given.Keywords：Wavelet transform;edge extracting;optical correlation;dividing image- 61
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Published：2020-08-12 -
Chaos generation based on neural network
Abstract：Back propagation neural network and chaos dynamics are combined in this paper. The global-optimum and dynamic-adjusting neural network is trained by the chaos series from non-linear system so as to approach the mapping feature of that system. So, a chaos generation scheme based on the neural network is proposed. By using nonlinear neural network with learning ability, this scheme doesn't have to be designed to be a single system structure for a certain nonlinear chaotic map. At last, using DSP technology, a Chaos Neural Network Co-processer Flashboard is made based on the CGNN. The chaos is used as a encrypeted key in the encryption telecommunication.Keywords：Chaos;BP Neural Networks;DSP- 56
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Published：2020-08-12 -
Measuring technique or weak radiation spectrum
Abstract：The multichannel parallel measuring technique was successfully applied to conventional scanning spectrometer, and the spectral coded measuring system based on WDP500-2A plane grating monochrometer has been developed and tested. With the entrance slit and exit slit of the monochrometer replaced by two multislit encoding mask respectively, the system not only has high radiation flux but also achieves the advantage to measure multispectral elements simultaneously, all these have remarkably improved its performance to analyze the weak radiation spectrum. To simplify the encoding kinetic mechanism, the masks which have cyclic encoding configuration have been designed. The slits in the encoding mask have been made into the shape of circular arc so as to compensate the spectral line curvature of the grating and reduce the metering error effectively.Keywords：multichannel technology;modulation spectrometry;S-matrix- 50
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Published：2020-08-12 -
Partial least-squares method for calibration with NIR spectrophotometer
Abstract：Near Infrared Reflectance(NIR)spectrophotometer is widely used in analyzing grains, water and oil. The spectrophotometer is able to analyze without destroy the chemical property of sample. There are many methods in its quantitative spectral analyses. Partial Least Squares(PLS)method is a good alternative to the more classical multiple linear regression. 40 tobacco sample data are described to illustrate the spectrophotometer calibration on PLS regression and Multiple Linear Regression(MLR). The result is related to calibration in chemical analysis. The values of components from PLS method is more precise than that from MLR method. It is proved that the PLS regression is a powerful multivariate calibration method and more suitable to the on-line or real-time analysis.Keywords：NIR spectrophotometer;partial least-squares method;quantitative calibration methods- 57
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Published：2020-08-12 -
Young's modulus measurement for micro-machined material
Abstract：It is necessary to measure Young's modulus of micro-mained materials because of the special manufacture process by using silicon etching technique. This is a new theme proposed with the appearance of micro-machined parts. In this paper the published methods of Young's modulus measurement for micro-machined materials are summarized, after that, both acoustically-excited and instantly-excited methods of Young's modulus measurement for micro-machined materials are proposed. These two methods have some features such as simplifying the test devices, easy operation and high accuracy.Keywords：Young's modulus;micro-machined material;acoustically-excited;instantly-excited- 83
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Published：2020-08-12 -
Elastohydrodynamic behaviors or point contact with surface transverse waviness
Abstract：The surface roughness has a considerable impact on the success of the lubrication conditions on some occasions. The model of point contact and mathematical model of surface transverse waviness are described on the basis of the study on the characteristics of point contact with regard to surface roughness. And time-dependent solutions are obtained employing a numerical method. The elastohydrodynamic lubrication behaviors of surface transverse waviness are analyzed in pure rolling conditions, and the characteristics of film pressure and film depth varying with parameters in contact area are revealed.Keywords：surface transverse waviness;point contact;elastohydrodynamic lubrication- 53
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Published：2020-08-12 -
Low noise electronic design method for laser range finding and tracking system
Abstract：There are all kinds of noises in electronic component and device, photo-translating device, e. g. shot noise, 1/f noise, thermal noise and background noise in system etc. Noise reducing is all along the main task of. increasing the active distance of system. In this paper, based on the essential theory of noise, the primary noise source and the design method of low noise for laser range finding and tracking system are demonstrated in engineering field. An example of design procedures for the head amplifier applied in engineering is introduced.Keywords：Narrow-band filter;shot noise;thermal noise- 42
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Published：2020-08-12 -
Soft X-ray slit transmission grating spectrograph
Abstract：The principle of soft x-ray slit transmission grating spectrograph is introduced in this paper and the resolution calculation formula can be obtained. Simultaneously, the geometry structure and corresponding parameters are given. On the condition of vacuum, some experiments on target shooting for different materials are carried out. The soft x-ray spectrograms of different materials are gained and from these spectrograms, we can conclude the spectroscopy and do some plasma diagnoses. Some good spectrograms are chosen from the result and are scanned by microdensimeter. From it, the relationship between the light intensity and the distance can be gained. It can be used in demarcation experiment and some quantitative analysis on elements.Keywords：Soft X-ray;slit grating;spectrum resolution- 49
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Published：2020-08-12 -
Calibrating the pointing precision of satellite laser ranging theodolite by observing stars
Abstract：The pointing precision of the satellite laser ranging theodolite is a key factor, which affects the blind-tracking and daytime observation. It can be improved by observing the stars and thus meet the observation demands. A method of calibrating the pointing precision of the laser ranging theodolite by observing the stars is described in this paper. Firstly, the model of state parameters is established, which will affect the pointing precision of theodolite. And then, the state parameters are obtained via choosing and observing some stars. Finally, The calibrating result of laser ranging theodolite in Changchun Observatory is also presented in this paper.Keywords：stars;calibration;satellite laser ranging;Theodolites;pointing precision- 43
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Published：2020-08-12 -
Method of measuring star at sea in daytime
Abstract：The theodolite designed for measure ship is a special optical equipment based on TV tracking and measuring for the use of navigation orientation system. When the measure ship carries out the measure assignment, it provides exact course data via measuring fixed star day and night. Its principal functions are to obtain undershoot error, count course angle and revise course error of inertia navigation system. For a variety of reasons, the measure in daytime can not meet the case. This article brings forward and discusses a new method of video manual interpretation.Keywords：measuring star in daytime;undershoot error;course error;Video interpretation- 72
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Published：2020-08-12 -
Producing and welding of tiny bridge-belt
Abstract：In order to solve the difficulties in producing and welding tiny bridge-belt,twn methods- producing by electrochemical etching and laser welding with powder cladding were put forward. The scheme is proved to be successful and practical in meeting the requirements of low cost, high quality and batch processing. These methods can also be extended to produce and weld other tiny and frail work-piece.Keywords：tiny bridge-belt;electrochemical etching;powder cladding;laser welding- 46
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Published：2020-08-12 -
Method or improving measurement precision for optical fiber sensor
Abstract：Improvement on measuring precision of a optical fiber sensor, based on principle of laser interference, was proposed through the investigation of both the optical system and the opticalelectron measuring system. The theoretical foundation, the selecting principle of circuit parameters and the designing method of preamplifier were given and analyzed in detail for the phase modulation of low noise of weak signal and the demodulation procedure of telephone digits. A precision of 0.05nm for micro-displacement measurement has been obtained by this new method.Keywords：optical fiber;measurement;Noise- 95
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Published：2020-08-12 -
Algorithm for misalignmental determination in computer-aided alignment of optical system
Abstract：How to determine the misalignment quickly, exactly and constantly is the key to the technology of computer-aided optical alignment. First, the mathematical simulation, which is the relationship between the misalignment and the aberrations is founded. Then, the concept of pseudoinverse and the algorithm of the singularity robust inverse are proposed in order to solve the problems of the numerical instability and the result inaccuracy which result from the solution for leastsquares method directly. Finally, the simulant calculation is processed using the numerical analysis model established in this essay. The result shows that the computation method is rational and effective.- 58
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Published：2020-08-12 -
GOMTool for system analysis
Abstract：Graphic Object Modelling Technique is an object-oriented system analysis method. It was developed on the basis of OMT(Object Modelling Technique)and applied to the software development of telecommunication. GOMTOOL is a tool in GOMT, which includes drawing graghics,checking models and generating text documents. In this paper,the design and implementation of GOMTOOL were introduced, which included how to design a graghic tool, check consistency and integrity of models and produce text documents. The tool was developed by visual C++.Keywords：object-oriented;object-oriented technique;object modelling technique;graph- 62
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Published：2020-08-12 -
Application of computer vision in detecting system or engine's surface defects
Abstract：Using the computer vision technology and the machine servo system, the defects on the cylinder-bore's surface are detected automatically. The main problems solved in this paper are how to segment the image of the cylinder-bore; how to select threshold value; how to determine the object defects. To solve the problems, the value is chosen by the histogram average fitting method, the defects and the sizes are acquired by the regression formula. Experimental results show that the method has the features of high precision and high automation, which overcomes the weaknesses in traditional detecting method.Keywords：defect detect;computer vision;engin- 58
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Published：2020-08-12 -
Overview of non-traditional micromachining technologies
Abstract：The research activities on non-traditional micromachining technologies to shape microstructures with 3 DOF and to make microstructures with ultimate size are summarized in this paper. Compared with silicon process and LIGA process, the non-traditional micromachining technologies without mask such as stereolithography, micro EDM and micro mechanical machining have got great progress in recent years, which have advantages especially in shaping microstructures with 3 DOF. At the same time, SPM processing technology accelerates miniaturization to ultimate size area. The research and development of micromachining technologies by integrating multidisciplinary novel ideas and advanced technologies will give the possibility for getting much further progress in MEMS/micromachines.Keywords：MEMS;Micromachine;Micromachining;stereolithography;micro EDM;SPM processing- 73
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Published：2020-08-12 -
Development of microgripper technology
Abstract：Microgripper technique was one of important parts in micromachine techniques. Firstly, the application background was recounted in the paper. The development and actualities of research in microgripper technique were reviewed. Secondly, microgrippers were classified. The structural arts and work principle were analyzed. Finally, the development of microgripper techniques was prospected.Keywords：Microgripper;MEMS;review- 67
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Published：2020-08-12 -
All-solid-state Q-switched lasers with Nd3+-doped crystals oscillating at 1.0μm
Abstract：The all-solid-state pulsed Nd3+ laser, pumped by quantum well laser diodes(LDs)and oscillating around 1.0μm, are remarkable for their compact structure and reliable performance and can be widely used in many fields. In this paper, the recent progress and application of these all-solid-state Q-switched laser are reported, mainly including actively(electro-optical or acousto-optical)Q-switching and various passively Q-switching techniques. The experiments show that the employment of the Cr4+ doped crystals as passive Q-switches may result in high repetition rate and high peak power pulsed output and is much suitable for the development of low cost, medium or low output pulsed lasers.Keywords：LD pumping;all-solid-state pulsed laser;Q-switching technique- 53
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Published：2020-08-12
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