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Issue 12 ， 2008
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Real FFT based on graphics processing unit for image processing
Abstract：Through the analysis of the general real Fast Fourier Transform (FFT) algorithm, a improved real FFT algorithm is presented based on Graphics Processing Unit（GPU）. General real FFT reduces the computation consumption of the conventional complex FFT by about 40%, and the presented real FFT improves the reduction to 50%. On the basis of the specific configuration of the data storage, the presented real FFT can be applied in two directions continuously to calculate the two dimensional Fourier transform. What’s more, the parallel real FFT transform can be implemented by using the 1D complex FFT function from the CUFFT library. The precision and the efficiency of the presented real FFT are inspected by the Wiener filter’s application. The image processing results demonstrate that the presented real FFT is operating properly and working well. With the help of the presented real FFT, Wiener filter can restore a 2048x2048 8-bit image degraded by motion in 19.26ms. It is 2.34X speed compared to the Wiener filter based on complex FFT on GPU, and is 37.46X speed compared to the Wiener filter based on real FFT on CPU. The experiment results show the presented algorithm is of practical use.Keywords：real FFT;image restoration;GPU;real-time computing- 26
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Published：2020-08-13 -
Non-uniformity correction in stray radiation suppression of infrared optical system
Abstract：The remnant stray radiation may cause image anomaly after taking suppressiones of optical and mechanical design in infrared optical system, Such as movement of lense during zooning may change the solid angle of narcissys ,which caused narcissus variation in the system. To minimize the effects, we provided a direct and fast method for suppressing the narcissus variation by two point non-uniformity correction. As an example, the stray radiation analysis and suppression of an infrared zoom optical system is presented. The result confirms that the method can improve image anomaly caused by remnant stray radiation .The disadvantage is reduction the contrast of the image.Keywords：stray radiation;narcissus;100% cold-stop efficiency;non-uniformity correction- 31
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Published：2020-08-13 -
The Design and Analysis of the Infrared Imaging System for Cloud Meteorological Observation
Abstract：The cloud as the goal, the infrared band of the goal and background was analyzed, and the work band of the infrared imaging system for cloud meteorological observation and the main technical parameters for the infrared imaging system were determined. The optics and structure of the infrared imaging system for meteorological measuring cloud which was based on uncoled infrared focal plane array (UIRFPA) detector were designed. Adaptive Non-uniformity Correction (NUC) for infrared images and the focusing mechanism on temperature were designed for the system.Keywords：Cloud meteorological observation;Uncoled infrared focal plane array (UIRFPA);Non-uniformity correction (NUC);infrared imaging system- 53
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Published：2020-08-13 -
Airborne Electro-Optical imaging equipment to test the design of the system
Abstract：Along with the technical development, the aircraft-borne electro-optic imaging system is getting more and more complex, system's test is also getting more and more remarkable to equipment's potency and the expense influence, but the present product universal existence testability design consideration insufficiency, the automaticity not high, the failure diagnosis does not arrive and so on questions. In order to sharpen the aircraft-borne electro-optic imaging system's testable ability, this article has carried on the comprehensive testable system design to the equipment, has specially used the method which unifies the fuzzy theory and the expert system, has solved the existence shortcoming, may cause the failure diagnosis rate to reach above 97%. Therefore, uses the method which in the testable design unifies the fuzzy theory and the expert system is effective.Keywords：airborne equipment;test;fault diagnosis- 31
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Published：2020-08-13 -
Engineering analyze of airborne optoelectronic platform frame structure
Abstract：Considering practical environment, whether parts in an airborne optoelectronic equipment may break, deform? How much deform of a part is? If it possible utilizing less material in a part and it’s performance is not affected? Using engineer analysis software we tackle the problem. Expounding characteristic of airborne optoelectronic platform frame structure show us syntony frequency is importation, adding sustentation and bore can increase it, minishing moment of inertia by reduce distance part to rotor can increase it too. Setting XXX optoelectronic platform frame seat structure for example, describe the progress of engineering analyze, by drawing as a result, stress, meet an emergency, distortion, safety factor can keep a view manifestation completely, we find out the weak link and redundancy part.The examples in the article illustrate guidance and importance of engineer analysis, it supplies us guidance for a better design.Keywords：Engineering analysis;drawing as a result;weakness link and part of redundancy;guidance and importance- 50
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Published：2020-08-13 -
Study on method for geometric superresolution based on subpixel
Abstract：In order to enhance the resolution of CCD pixel while keeping the pixel dimension, the problem of CCD geometric superresolution is researched. Beginning with the actuality of superresolution, the existing methods and correlative shortcomings are given, and the mathematic model of the subpixel superresolution is constituted. The method for improving the geometric resolution of CCD based on subpixel is presented. Two linear CCDs, which are shifted by half dimension of the pixel in the line direction, are integrated in one component. In operation, the reading_out time is reduced by half. At last, the image data is interweaved to synthesize the high resolution image. Two methods, bilinear interpolation and sub_pixel imaging, are simulated with the software MATLAB7.0.1. The qualitative and quantitative analysis is given. The simulation show that in sub_pixel imaging method, the resolution of synthesized image, compared with low resolution image, is enhanced by about one times, and the PSNR, compared with bilinear interpolated image, is enhanced by 0.2 dB. Sub_pixel imaging method could synthesize high resolution image in real time, and the image blur, which is induced by under sampling, is mitigated greatly in this method.Keywords：Charge Coupled Device;Subpixel;Geometric Superresolution- 35
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Published：2020-08-13 -
A new kind of shock absorb structure of aero remote sensor
Abstract：By aviation optical remote sensor vibration-induced vibration is like shifting affect aviation optical remote sensor imaging quality one of the main factors, Therefore a good damping system for improving remote sensing imaging system for clarity and resolution capabilities is very important. This paper presents different from the traditional pressure-loaded damping structure of a new type lifting - damping structure, the installation of sensors suspension, solve the pressure-mounted sensors installed in the bottom of the problem of space, they can achieve good damping effect Image quality assurance. After analysis indicates that the vibration of aircraft structure completely overload conditions of the strength requirements. The damping structure has been applied to engineering practice.Keywords：Aero remote sensor;Shock absorb;Suspend installing- 38
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Published：2020-08-13 -
One Method of Autofocusing with Automatic Calibration for Aerial Camera
Abstract：The aviation camera is an airborne precision optical instrument, and the environment parameters of high altitude such as temperature , pressure are influenced the optical system badly, especially brought the transformation of focus.In order to acquire the vivid image, the real-time and precise autofousing technology is very necessary. The paper introduced a method of autofocusing with automatic calibration , and the relationships of grating constant，the circumvolve velocity of reflector and response time of receive component were analyzed, in addition the direction of grating and the position of focus plane were discussed, at last the choose of lamp-house for autofocusing were researched. The method of autofocusing with automatic calibration were used in some type aviation camera, and which was satisfied the request , and acquired good image.- 34
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Published：2020-08-13 -
Research On Forward Motion Compensation In Panoramic Aerial Camera With TDI CCD Based On DSP
Abstract：It will inevitably bring motion, which is called forward motion, to aerial images due to relative movement between scenes and sensitive medium. In order to improve aerial image resolutions, the motions must be compensated, so the scene and sensitive medium will keep relative stillness when photographing. First, this paper analyzes causes of image forward motions, relationships between compensation precision and requirements for servo control system, and operations of compensation structure-scanning mirror, then proposes a novel kind of forward motion compensation system using DSP chip, which implements control algorithm digitally. Meanwhile this paper also discusses some critical issues, such as compensation precision, algorithms selection, phase calculation and time constrains in servo control system when using DSP. Finally this paper describes hardware architecture and software flow chart suiting for engineering.Keywords：aerial camera;forward motions compensation;DSP implementation- 47
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Published：2020-08-13 -
Research of the Scanning Angle of Panoramic Aerial Camera
Abstract：The scanning angle (SA) is an important parameter of Panoramic Aerial Camera. The angle of SA has relations with the scanning start angle (SSA), the target slope angle (SA) and the overlap rate. This paper analyzes the relationship of them and suggests that the current method of calculating SA is very difficult to be realized in engineering. It proposes a method of calculating SSA and SA according to TSA. Its main characteristics are, with achieving the overlap rate as a premise, to calculate SSA and SA reasonably and to try to put the target into the middle of swath coverage, making the coverage as wide as possible. The method is very simple and is easy to be realized in engineering.Keywords：scanning angle;panoramic aerial camera;overlap rate- 40
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Published：2020-08-13 -
manufacture fine optical performance surface of aspheric silicon carbide mirror
Abstract：In order to manufacture fine optical performance surface of aspheric silicon carbide(SiC) mirror, the technology of surface modification for SiC mirror is presented, and the technology of fabrication of surface modification aspheric SiC mirror is studied. First, ways of surface modification on SiC mirrors are introduced, and especially the technology of ion beam assisted deposition(IBAD)-Si on SiC mirror surface is emphasized.Then several polishing agents, such as CeO2, Al2O3 and SiO2, are used in experiments for polishing SiC samples with surfaces modification. It is verified that high polishing efficiency is acquired in experiment with polishing agent of CeO2, and the best optical surface is fabricated in experiment with polishing agent of SiO2. Finally, on the basis of experiments, 650mm×200mm off-axis aspheric SiC mirror with surface modification is manufactured by the technology of computer-controlled optical surfacing. The testing results indicate that the surface accuracy of the aspheric SiC mirror with surface modification is better than λ/50(RMS)（λ=0.6328μm）, and surface roughness is less than 1nm(RMS).Keywords：off-axis aspheric;silicon carbide mirror;computer-controlled optical surfacing;surface modification- 43
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Published：2020-08-13 -
opto-Structural System design of long focal length wide-field optical remote sensor
Abstract：According to the long focal length wide-field off-axial three mirror system of high quality in space telescope , the majorized issue of the opto-Structural System was discussed. To design the lightweight precision truss, which is fitted to characteristic of the light high resolution space camera, the method of mode analysis and the principles of designing the main truss are studied. Then the analysis of its supporting structure was made by means of FEM(Finite Element Method)and optical design software. It has proved that the performance such as self-weight deflection, fundamental frequency, thermal stability of the long focal length wide-field off-axial optical system all meets the requirement.Keywords：optical remote sensor of long focal length wide-field;system of TMA;supporting structure;truss- 67
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Published：2020-08-13 -
Testing technology for large aperture SiC asphere mirror
Abstract：In order to realize testing of a large aperture SiC convex asphere, ,aberration free testing method and compensator tesing method are analyzed. After majorized comparison, null lens testing method is selected. Offner null lens for large SiC Convex asphere are designed．The design results indicate that the precision of the system’s is PV：0.0082，RMS：0.0029（=0.6328nm）， large aperture zygo interferometer is used and convergent testing method is adapted . The final testing results or the mirror is 0.022（RMS）. Th e design method is universal and the design results can be used in the compensator design for other convex SiC mirror．The testing result of convex asphere is improved, the selection of the material and supporting structure etc. is majorized, it give more chance for new style of convex asphere mirror.Keywords：Convex asphere;SiC;null test;null lens design- 44
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Published：2020-08-13 -
IAD-Si Coatings on RB-SiC Space Mirrors for super-polished surface
Abstract：To eliminate surface limitation caused by Silicon impurity in RB-SiC apace mirrors, a relatively thick Si film is deposited on well finished RB-SiC substrate by ion assisted depositing(IAD) process to provide a better polishable surface. Firstly，The process of RB-SiC surface coating is summarized, on the polishing point of view. Secondly, severial properties of IAD-SiC coatings were tested. Results show that the amorphous film can satisfy all requirements of RB-SiC surface coating technique. Then, polishing experiments on 10±0.5µm thick IAD-SiC layers were accomplished and testing results of surface roughness and reflectivity were given: surface roughess of the coating after polished achieved less than 0.5nm RMS ; moreover, reflectivity of IAD-Si polished surface with reflective films increased up to 4.5% than that of RB-SiC in 360-1100nm wavelength. The results indicated that IAD-Si coating technique and the new polishing process showed an access to high quality RB-SiC space mirrors.Keywords：RB-SiC;surface coating;IAD-Si;surface reflectivity- 72
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Published：2020-08-13 -
Study of Equipment for Testing of Airborne Opto-electronic Reconnaissance Platforms
Abstract：The article researched based on a requirement of testing for Opto-electronic Reconnaissance Platforms of the institute. We expound and proved the principle of testing method for platform dynamic capacity. Moreover, the article analyzed the possibility of application of new equipment for dynamic testing. The author researched about the principle and design ideal of the new equipment based on the existing technology standard. Followed, we talk about the key parts of the new equipment, which based on the friction transmission principle .The article analyzed the error of the design and real process course. At last, we catch the conclusion and the real three-dimension designing. The whole conclusions of the researchment offered a new thinking for similarly testament of air-load platform in laboratory condition.Keywords：Opto-electronic Reconnaissance Platforms;dynamic testing;ground target dynamic imitate equipment;friction transmission- 69
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Published：2020-08-13 -
Influences analysis of the pentaprism scannig system due to alignment error and fabrication angles error
Abstract：The highly accurate measurement of optical surfaces can be realized by means of pentaprism scanning system, in order to analyze the influences on the line-of-sight error and angles measurement error of autocollimator due to alignment error and fabrication angles error of pentaprism scannig system. According to rotation transform matrix and vectorial ray tracing theory, a versatile vectorial ray tracing function and a relevant analysis program was written by MATLAB. Meanwhile, second-order approximations for computing the line-of-sight error and angle measurement of autocollimator in a certain range were derived by a 2D second-order polynomial fitting. The analysis result indicated that during the scanning measurement, the influences on the line-of-sight error of in-scan direction and vertical angle measurement of autocollimator are constants due to pitch angle of autocollimator and fabrication angles error of pentaprism, and there are quadratic with the yaw angle and roll angle of pentaprism; the line-of-sight error of cross-scan direction and horizontal angle measurement of autocollimator are linear with the yaw angle and roll angle of pentaprism in the scanning. When the rail error is 10" in roll、10" in yaw, and the misalignments of the system are ±3", the max angle measurement error in scan direction is 0.0010666".Keywords：optical measurement;pentaprism scannig system;error analysis;vectorial ray tracing;MATLAB- 38
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Published：2020-08-13 -
The Research of Easy-carry Interferometer for Uncoaxial Three-mirror Reflective System Wave Aberration Testing
Abstract：In order to facilitate the detection and assembly of off-axis three-mirror reflective optical system, developed a portable interferometer. The equipment utilizes the flat mirror as the mirror one, through the optical system use plane wave transforming for spherical wave to interfere. The equipment rejects the traditional way that a standard spherical lens corresponded to an optical system under test, decreasing the number of standard mirror and reducing the cost. The test is faster and the result is accurate and reliable. It is not more than 5 kilograms, smaller size, portable, inexpensive, great prospects for development.- 26
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Published：2020-08-13 -
A method of examining the imagine planes’ illumination non-uniformity of optical system on photoelectric equipment
Abstract：Since non-uniformity of image-forming system on photoelectric measuring equipment seriously limits his working performances, we have done some research on measuring non-uniformity of image-forming system to improve its image quality. The article proposes a method of examining the imagine planes’ illumination non-uniformity of optical system on photoelectric measuring equipment. First of all, we calibrate the CCD of photoelectric measuring equipment using integrating sphere as an uniform radiant source. Then we examining the imagine planes’ illumination non-uniformity of optical system. For simulating the background of sky, integrating sphere was used to provide an uniform radiant source. The photoelectric equipment was putted on the front of integrating sphere, and take a picture .By analyzing the picture, the imagine planes’ illumination non-uniformity of optical system was measured. For improving the result, we use the two-point multi-section correction to correct the photoelectric response non-uniformity of CCD. A group of experiment results is offered at last.Keywords：integrating sphere;illumination non-uniformity;charge-coupled device;non-uniformity correction- 27
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Published：2020-08-13 -
Application of SiC and SiC/Al in the TMA space telescope
Abstract：The environment of application of the space telescope is described, the importance and the influence of the material selection is introduced, the new material SiC and the SiC/Al which have high-thermal conductivity property and high specific stiffness, is employed in the TMA space telescope, the result of analysis and test both proved that these new materials have improved the mechanical character and the thermal stability of the space telescope, and the space telescope adaptive ability in space environment is.Keywords：space telescope;Specific stiffness;thermal stability;SiC;SiC/Al- 45
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Published：2020-08-13 -
Development of full-automatic solar tracker and its applications
Abstract：This paper describes the full-automatic solar tracker's principles，structure，main function and application. The full-automatic solar tracker has two tracking mode which can switches freely. The two methods which can switch by themselves achieve high-precision automatic tracking sun all time. The successful development of full-automatic solar tracker in the absence of developed sensors improves the measurement accuracy of direct radiation and the total radiation，Solves the problem which signal wire of direct radiation instrument rounds each other and achieves full-automatic measurement of direct radiation. As full-automatic accurate tracking sun can automatic measure sunshine duration it fills a gap of automatic measurement of sunshine duration in our country. In addition it can carry out automatic measurement of scattering radiation. It has other applications too.Keywords：full-automatic;solar tracker;development;Application- 31
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Published：2020-08-13
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