A proper optical system is selected for a compact, wide waveband spaceborne hyperspectral imager by comparing with existing optical systems applied to spaceborne hyperspectral imagers. Firstly, the advantages and disadvantages of optical systems for the hyperspectral imagers are discussed. Then, the principle and characteristics of three spectral-splittering methods with a prism, a grating or FT(Fourier Transform) as dispersion elements are compared and analyzed. Finally, based on the research objective of a hyperspectral imager, a reflective optical system is chosen. The system is composed of an off-axis Three-Mirror Anastigmatic(TMA) telescope and two Offner convex grating spectrometers. By changing the magnification of two spectral imaging systems, two array detectors with different pixel sizes can be matched. The detailed design results are presented,which indicate that the Modulation Transfer Function (MTF) of 128 wavebands from 400 nm to 2 500 nm is all over 0.6, distortion is less than 0.44% and the spectral bend(smile) is less than 0.03%. The chosen reflective optical system can satisfy the technical requirements of the compact spaceborne hyperspectral imager and can efficiently decrease the volume and weight. By enlarging the relative aperture of the optical system, the low diffraction efficiency of gratings can be compensated.

In order to minimize the mass of primary structure of a Long Slit Spectrometer (LSS), and to improve the robustness of structural response, the primary structure of the LSS was optimized based on robust optimization methods. The effects of the structure geometry tolerance and material property tolerance on the structure robustness were analyzed. Accordingly the structure geometry tolerance which has significant sensitivity to the structure robustness was adjusted. The robust optimization model of primary structure of the LSS with the constrained conditions of the fundamental frequency and the objective function of total mass was established. A Monte Carlo simulation and an ant colony optimization algorithm were applied to solve the optimization model. Experimental results show that the optimized structure has reduced the mass by about 17.5% compared to the original design. Although the mass of the optimal robust design is larger than the mass obtained by deterministic based optimization, it is insensitive to variations on design variables within a feasible region. The optimal robust structure design satisfies design requirements.

By taking the advantages of a Liquid Crystal Spatial Light Modulator(LCSLM) in large stoke, high density and a lower voltage driver, an adaptive optical(AO) system for correcting the aberration of the human eye was developed by using the LCSLM as a key element. The modulation principle of LCSLM was introduced and the relation curve between the phase modulation and the drive voltage was also measured by a ZYGO interferometer. Then, the Shack-Hartmann wavefront sensor and LCSLM were used for aberration detection and correction, respectively. For a subject eye with 5 m-1(5D) mopia, the wavefront error is reduced to 0.086λ PV and 0.013λ RMS after adaptive optics (AO) correction, which has reached the diffraction limit. Furthermore, the blurred photoreceptor cell on the fundus oculi is clearly imaged on a CCD camera. These results show that the LCSLM based adaptive optical system has the ability of correcting the aberration of the human eye efficiently, and the quality of image is also improved a lot.

In order to realize the possibility of a single mode fibre coupler used as a sensor, the theory of an optic fibre coupling sensor is analyzed. According to the relation that the coupler’s coupling ratio is sensitive to the coupled fused part length change and vibration frequency, a detection technology for strain and vibration parameters is proposed. The strain and vibration experimental system based on a micro-strain instrument and a cantilever is set up and its working principle is described in detail.The strain response of the fibre coupling sensor is investigated through a micro-strain test and the effects of temperature and transverse interference on the output ratio are given. Experimental results indicate that strain response of the fibre coupling sensor is excellent and the sensor temperature remains a constant in the coupling ratio range from 10% to 90%. The dynamic experiments of a piezoelectric sensor and a coupling fiber-optic vibration sensor are investigated and a 0-50 Hz low and 4 kHz high frequency responses are approved during the vibration testing. These results show that the single-mode fibre coupling sensor can measure a vibration signal practically, meanwhile,other influencing factors including the fused part materials, coupler structures and fabrication need to be resolved for engineering applications in the future.

In order to keep the temperature of CCDs on an attitude varied space camera within a limited range, a thermal control system of the CCD Focal Plane Assembly (CFPA) is designed. Base on the theory of differential thermal expansion between the two materials having different CTE values,a thermal switch as a crucial part in the thermal control system is designed. According to the calculation of the orbit, the obstructive relation of all parts and the characteristics of attitude varying, the scheme of two radiators controlled by a thermal switch is presented, and the thermal design of the CFPA is specified. The performance of the thermal design is simulated by the TMG software. The results indicate that the temperature fluctuation of the CCD is 12.34 ℃ under passive-thermal-control, whereas it is only 1.73 ℃ under both passive-thermal-control and active-thermal-control. Experiments show the thermal control system can meet the need of the mission and the thermal design is efficient and reasonable.

With the aim to resolve the influence of the performance degeneration of FBG sensors on multiplexed demodulation, the affects of reflection sidelobes on the demodulation of a series multiplexing FBG sensor was analyzed based on the demodulation theory of FBG strain sensors. When the performance of the FBG sensors was degenerated, it was found that the bandwidth of the reflection spectrum was broadened, the peak value fell, and the reflection sidelobe was augmented by both theoretical deduction and simulation. The effects of reflection sidelobes and the link-connected loss on the FBG multiplexed demodulation were analyzed in detail, then the floating demodulation threshold and suppressing reflection sidelobe were presented to resolve the effect and to reduce the error rate of the multiplexing demodulation. Finally, the theory is validated and the method is demonstrated experimentally. Experimental results show that the error rate of the multiplexing demodulation reduces from 11.36% to 0, and the accuracy of the measurement result is greatly improved.

Ion Beam Figuring (IBF) technology was investigated for application to a high-precision optical aspheric. With the analysis of the IBF system, the motion model formulas of an ion source subsystem were presented for figuring aspheric optics and other optics by the IBF facility. The de-convolved process of the dwell time function was transferred to a linear matrix equation, which could be easily optimized to get the optimized dwell time solution. Using an analysis of the location errors, this paper proposes that the final figure errors caused by the location errors of the ion source five-axis motion subsystem could be attributed to a coefficient factor. The best way to avoid the location precision requirements is to take both the ion beam material removal function and the location errors into account in designing the five-axis system accurately. The simulation example proves that the dwell time function obtained from this model is effective in assuring the final optical element figure precision(0.038 1λ).The final optical element figure errors from the location errors of the ion source five-axis motion subsystem are bound by the range of maximum difference. So this model can be used for all kind of optics to determine the dwell time function and to design the location subsystem error precision, and also to assure that the IBF process is stable and feasible at the minimal cost.

Several experiments to obtain a mid-infrared 4.65 μm laser output with a Second Harmonic Generation (SHG) in AgGaSe2 crystals by a 9.3 μm pulsed TEACO2 laser were introduced. Based on the principles of nonlinear optics and laser frequency doubling, the spectral line and time shape of the pulsed TEA CO2 laser were selected and controlled,respectively, to meet the basic requirements of the pumping laser source for the wavelength and time distribution. Then taking the laser source as the fundamental wave, the research work on the SHG is performed. Experimental results show that the same AgGaSe2 crystals made by the different manufacturers displays the different surface damaged characteristics, but the bulk damaged thresholds form all the crystals are higter than their surface damaged thresholds.The experiment offers a frequency-doubled maximal single pulse energy of 12.9 mJ and an average power of 940 mW.

The size and structure of a three-line array stereoscopic mapping camera are mainly determined by its optical system. To realize the miniaturization, lightening and high reliability of the camera,several kinds of optical system configurations,refraction,reflection and refracting-reflecting optical systems, are analyzed and compared by the requirements of the optical system. In accordance with the environment adaptability and structure layout of the camera,a telecentric system is adopted to design a new optical system to meet the requirement of stereoscopic mapping. The MTF value of each lens in designed optical system is close to the diffraction limit at Nyquist frequency of 77 lp/mm. The distortion of each optical system is less than 2.4×10-5 for the forward and backward sight cameras and 2×10-5 for the straight-sight camera.The tested result shows the MTF of each optical system can reach 0.43 at Nyquist frequency of 77 lp/mm, which is 0.2 higher than a static MTF in laboratory and meets the requirements of the mapping camera for precision.

A photon-counting imaging detector with a wedge-and-strip anode (WSA) can record position information on a single photon or incidence particle, so it can acquire the two-dimensional image of an objective under very low lighting conditions. In this paper, a detail description of a detector prototype built by us is firstly given, including its configuration and operating principle, then the imaging distortion of the detector is analyzed, correction methods are proposed and distortion-free images are obtained. Resolution tests are taken using a USAF1951 resolution target placed in front of the detector. The detected image shows that the 6th element in the 2nd group of the USAF1951 target can be differentiated by the naked eye. Finally, in order to remove the subjectivity error produced by human eye observation and to ensure measurement accuracy, the imaging modulation index is computed. The computed results show that, for the 6th element in the 2nd group of the USAF1951, its imaging modulation index can reach 57% and 37% in the vertical and horizontal, respectively. This result indicates that proposed detector prototype can differentiate the strips above absolutely with a 7.13 lp/mm, i.e., the spatial resolution reaches 0.14 mm.

With respect to the primary mirror of a large optical system, the influence of mid- and-high frequency errors on the Fractional Encircled Energy (FEE) based on classical scalar diffraction theory was analyzed. With the relation between full frequency errors and FEE, the mathematical model between the Gradient Root-mean Square (GRMS) errors of mid- and-high frequency errors and FEE was established by assuming that the surface error is a stationary Gaussian random progress.The numerical computation and actual surface profile data of the model were validated. It is found that the FEE almost declines in an exponential form with the increase of GRMS of the mid- and-high frequency errors, and the various frequency errors transform the edge energy of the ideal intensity distribution to the centre and wider domain of the intensity distribution.The energy transfer curve oscillates with the increase of the GRMS. It is concluded that the influence on FEE is less than 5% when the GRMS of the mid- and-high frequency errors are less than 12 nm/mm and 30 nm/mm,respectively, under the special optical diameter,and obtained results can be used to control the influence of mid-and-high frequency errors on the FEE and can provide a support for the further finishing and figuring of the optical surface profile.

The noise source and characteristics of a Solar Blind Ultraviolet Intensified Charge Coupled Device (SBUV-ICCD) are analyzed. As the single P-E(photo-electronic) response can be diffused into neighboring pixels in CCD when the system gain is to be set a higher value in working conditions,this paper takes the SBUV-ICCD as a liner and shift invariant,and imports the P-E pulse response into the calculation of SNR,then the Fourier transform is used to deduced a SNR model. This model uses a 2D Gaussian function to fit the single P-E pulse response of the SBUV-ICCD,and it is simpler than those of traditional methods. The effect of the gain on the SNR of SBUV-ICCD is analyzed and the SNR of the SBUV-ICCD is measured when the irradiance is between 10.3 pW/cm2 and 810.6 pW/cm2.The results show that the RMS of the module is 0.78,which can be used in the analysis of performance of SBUV-ICCD.

To achieve a steady harmonic mode-locked pulse (HMLP), the theory of rational harmonic mode-locking and the transmission characteristics of a nonlinear amplifying loop mirror were analyzed. A figure-8 shape pulse laser including an outer ring and an inner ring was constructed to theoretically and experimentally investigate the passively mode-locked technology of an erbium-doped fiber laser. By modulating the pump power to 167 mW,146 mW or 126 mW,not only a steady HMLP,but also several rational HMLPs were observed. It is found that these pulses show the same properties as those of 3th-order,5th-order,6th-order HMLPs by analyzing the repetition rate of pulse train. The reason is that the Sagnac ring in the figure-8 shape pulse laser plays the same role as the modulator used in an actively mode-locked pulse laser.

In order to realize the spectral analysis of a weak signal, a Hadamard spectrometer with a high luminous flux and high resolution is established by using a Offner optical structure in the system. The performance of Hadamard S silt and Hadamard cyclic-S silt is compared. Then,the multi-micro-silicon-slit matrices are produced by MEMS technique,and the diffraction phenomenon is analysed by using the software of Matlab. Based on the diffraction theory, the diffractive formula is presented. A set of experiments are carried out to compare the performance of Hadamard S15 and Hadamard cyclic-S15,results show that the luminous flux of the presented device with Hadamard S15 is 1.45 times that of the device with Hadamard cyclic S15.The experiment verifies that the programmer using the Matlab language is reasonable,the measurement system is stable,and the S15 slit is fit for the Hadamard spectrometer.

A new method of Electrical Discharge Machining(EDM) for small-holes was presented, in which the critical value of machining could be less than that generated by a primitive EDM system. The characters of small-hole EDM in an area equalization by the current dividing were studied,and the effects of the current dividing on the drilling speed,electrode wear and the discharge gap were researched. Research results provide a deeper understanding for the small-hole EDM in area equalization by the current dividing. Experiments to verify the stability and feasibility of the EDM in area equalization by the current dividing were carried out and experimental results show that the drilling speed and discharge gap decrease a little and the electrode wear increases slightly. Moreover, there is a consistency in process effect between single and double electrodes, which is conductive to the control of a dimension precision. Finally,a 0.6 mm×0.6 mm square is obtained through the current dividing using the process parameters of 1 mm×1 mm in the signal electrode EDM, which proves that the method in EDM by the current dividing is effective for the small-hole machining.

Wire Electrochemical Micromachining (WEMM) is a new method of micro fabrication. In order to improve the machining accuracy, the in situ fabrication of a wire electrode and the following process of the WEMM are integrated into one system, and the WEMM technology by using in situ fabricating wire electrode is investigated in this paper. Effects of the diameter of wire electrode on the machining accuracy of WEMM are investigated theoretically. Then,the in situ fabrication of wire electrode is proposed to fabricate a micro meter scale wire electrode, and the tungsten wire electrode with a diameter of 5 μm is electrochemically fabricated in situ for the production of micro structures. Micro blades with a slit width of 20 μm and micro sharp-angle structures with a radius of 1 μm are machined experimentally. Experimental results indicate that because of the compatibility of the technologies, the in situ fabrication of wire electrode can improve the machining accuracy of WEMM, and the micrometer scale structures can be fabricated.

To improve dynamic performance and to meet the demands of high precision,fast transient response and real-time tracking ,an automatic control method for stabilizing a airborn platform is researched.On the basis of the principle of Adaptive Inverse Control(AIC), an adoptive inverse control system is designed.Then,the system takes the model reference adaptive inverse as a controller to stablilize the axis of the platform and utilizes its character of open circle to improve the system capability. The algorithm for the identication and control of model uses the least square method (LSM) to identify the parameters and the PID control and AIC analysis to compare its output. Simulation experiments indicate that the precision of the AIC system can reach 29″, which shows the proposed system has several advantages of sensitive response, non-overshoot, good anti-disturbance, and minimal stable error. Its dynamic/static performance is superior to those of conventional PID methods.

In order to remedy some defects in a traditional handy system for measuring the crack width in a concrete structure ,such as the difficulty inaccuracy focusing and the blur image due to the small focus depth and aberrations, a new system based on a wave-front coding was designed to extend the focus depth.The normalized parameters of a cubic phase plate and the relationship between these parameters and their corresponding real design parameters were discussed. Then a handy measurement system based on the wavefront coding with CODE V was designed. Finally, the cubic phase plate was fibricated and a preliminary experiment was carried out. Experimental results indicate that the field depth of the wavefront coding system based on a single lens can be extended to 15 mm when the resolving power is 50 μm and the F number is 6, which is 4.5 times as deep as that of traditional optical systems in theory at the same F number. The system can satisfy the requirements of extending focus depth and imaging in measuring the crack width of a concrete structure.

A kind of focusing structure for a space remote sensor was designed, which combined a harmonic drive,a screw, and a line guide rail to compensate the shortcomings of traditional focusing structures. A motor model was selected according to the analysing on a resistance torque,then the resolution of focusing structure was calculated to be 0.43 μm. The structure was tested in a dynamic environment with the whole machine, and focus precisions were compared before and after the dynamic environment testing. The testing data indicate that the line tilt is less than 20″ and the displacement error is less than 5 μm, which meets the requirement for use.Experimental results prove that this focusing structure is characterized by his compact volume, high rigidity and well precision.

Magnetically Suspended Flywheel (MSFW) is an actuator for the high precision attitude control of spacecrafts such as satellites.In order to improve the reliability and flexibility of a MSFW control system for space applications,a FPGA-based digital controller for Active Magnetic Bearing (AMB) is investigated. Firstly, the model of the magnetic bearing system is set up and several kinds of suitable control strategies are chosen. Then, by using the idea of on-chip hardware and software co-design, an AMB controller based on a FPGA and a LEON3 soft processor is presented,and a prototyping platform is built to test control algorithms and to verify the system performance. Finally, a self-repairing FPGA-based AMB controller is proposed. Comparing with the DSP-FPGA-based AMB controller, the FPGA-based controller has decreased the failure rate by 10% and the board area by 30%. Experimental results indicate that the beating of flywheel rotor and the torque output error are less than 20 μm and 4×10-3N·m,respectively, and the inconsistency between positive and inversion is less than 10% under the control of the FPGA-based AMB controller and the working speed scope of MSFW.These data prove that the proposed controller has achieved a higher precision.

To improve the measurement and evaluation methods of a machined micro/nano scale V-shaped groove, a single-point diamond turning was employed to machine the V-shaped groove of optic glass in micro/nano scale, and a non-contact laser measuring technology was used to analyze the topography of machined V-shaped groove. The micro/nano scale cutting of the V-shaped groove of optic glass was conducted by using the sharp cutting edge of a single crystal diamond. Then, the machined V-shaped groove was measured by a 3D laser meter to compare its profile,and the evaluation mode of the shape error PV and tip arc-radius of the V-shaped groove was established. Finally, the form principle of cutting depth and the angle of V-shaped groove were analyzed and the effect of sub-micro scale cutting depth on the shape error PV and the tip arc-radius was investigated. The results show that there exists a critical cutting depth of 0.386 μm,when cutting mode is transferred from a brittle cutting to a ductile cutting in sub-micron-scale space. In ductile mode cutting with a cutting depth less than 0.386 μm, the diamond tool tip can be replicated to the workpiece surface and to produce a sub-micro-scale V-shaped groove with a cutting depth less than 0.386 μm and a shape error PV about 0.103 μm. In addition, the tip arc-radius of V-shaped groove decreases in ductile mode cutting when the cutting depth is decreased, so to get a V-shaped groove with the tip arc-radius of 0.182 μm,the cutting depth should be controlled below the critical V-form cutting depth of 0.365 μm. These results also show that the parameterized model of shape error PV and tip arc-radius can be established by using 3D data derived from non-contact laser measurement, and can be employed to evaluate the machining precision of micro-scale V-shaped grooves.

In order to achieve the accuracy of short-time navigation of a Strapdown Inertial Navigation System (SINS),a navigation error mathematic model is established, and the effect of inertial device errors on the navigation accuracy of the system is analyzed. Aiming at the characteristic of short-time navigation,the navigation equation of carrier in a navigation coordinate is simplified with strapdown inertial navigation mechanism,then the attitude error equation of carrier is deduced by installation errors of inertial devices and the equivalent zero-shift of the gyroscope. Combing with the navigation equation,attitude error equation and the errors of inertial devices,the mathematic models of velocity errors and position errors are derived. Based on the error mathematic models, the state-space model and the block diagram of error models are established. Finally,a module of error models is built in Matlab/Simulink and is combined with the strapdown inertial navigation algorithm to calculate navigation data in ground within 150 s. The experimental results show that the relative system error of x-axis of navigation coordinate is less than 20%, and those of y-axis and z-axis are less than 4%, respectively. Furthermore, the influences of change of an accelerometer accuracy on SINS navigation errors are analyzed.

In order to realize the aircraft attitude measurement,this paper presented measurement methods to obtain the aircraft attitude by using the spatial cosine relationship in the single-station theodolite and using the planes to intersection in the multi-station theodolite. When the single-station theodolite was introduced in a measured distance from the aircraft posture information,an exhaustive approach was used to access to the aircraft axis of the feature points and the location in the space was used to obtain space posture parameters. When the multi-station theodolite was introduced to get the information of the aircraft flight attitude by using the planes to intersection,a two-dimensional image was used to obtain the objective axis by Hough transform fitting algorithm. And then,the vertical distance of the origin to the central axis of a target and the angle between the central axis normal of the targer and the X-axis were calculated to obtain the linear equation in the two-dimensional plane.The two-dimensional axis of target image and the camera system's optical center can only identify a space plane,then the planes to the intersection method was used to obtain the space axis and to get the aircraft yaw axis angle and pitch angle. Experimental results show that that of the single-station theodolite is less than 1° when its distance is less than 6 000 m and that of the multi-station theodolite is less than 0.6° when its intersection angle is between 30° and 150°.According to the test results of the precision comparing,it is concluded that the mathematical model is correct and the algorithm is reasonable in extracting effectively parameters of the aircraft's attitude.

A method based on the feature extraction of a wavelet packet energy spectrum and the recognition of a Support Vector Machine(SVM) was presented to solve the problem of recognizing the floating and suspending impurities in ampoules. Firstly, an impurity zone’s image was extracted as an object image through the image sequence difference and point detection division. Then, a 1D signal could be obtained through adding the ROI row by row in the axis direction of an ampoule. The 1D signal was decomposed by a wavelet packet, the independent primary components in the wavelet packet feature vector were extracted by using Primary Component Analysis(PCA), and the wavelet packet energy spectrum of the independent primary components was taken as the feature of impurity types.Furthermore,the extracted feature was taken as the input vector of a SVM,and the sample features could be classified rapidly by a sequential minimal optimization method through training. Different types of core functions and corresponding parameters were selected for training and testing in the experiments,and obtained results show that the recognition period of SVM has decreased by 60% and the recognition precision improved by 35%,respectively, as compared with those of the BP network. This method can meet the requirements of the floating particles for feature extraction and rapid recognition in production.

In order to monitor the working state of a control cell of drift angle for an optical remote sensor and to test its function, performance and reliability, a closed-loop test method for the controlling cell of adjusting drift angle in real time was given. Using this method and the computer technology, a testing system was designed to analyse the controlling signals and form the information of a coder by the control tactic of drift angle. Then, the information of the simulation coder was feedbacked to the controlling cell to realize the tests for the control tactic, driving ability and the error disposal. The controlling cell of adjusting drift angle was tested in a work frequency of 1.2 kHz, a least interval of coder feedback of 10 ms and the warp of feedback less than ±1 code. The experimental results show that the testing system can exactly monitor the working state of the controlling cell of drift angle for the remote sensor and can cover the entire path in the control tactic,which totally satisfies the requirements of the controlling cell of drift angle for closed-loop and real time testing.

The interior origination element biases between a laser scanner and a navigation system were calibrated to satisfy the survey precision requirement of a lidar. Firstly, control areas are detected and ascertained through laser intensity map, and then the control points are calculated with laser footprint measurements averagely within a control area. Equations including biases and navigation parameters based on control points are set up for optimal estimation. The general least square method with a white technology is adopted to handle the coupled noise covariance and to give an optimal estimation of biases under the least square principle. Experiment results show that this algorithm can restrain imprecise coefficient matrix errors caused by a navigation system. The precision of fixing angle biases is superior to 0.01° and the precision of fixing level-arm biases is superior to 3 cm. As compared with traditional methods in general, the average estimation precision has improved by 6.54% under the condition of a relaxed small angle and by 5.27% in the measurement noise to be amplified. These data confirm that the algorithm can satisfy the calibration requirement for both precision and robust under strong noise conditions.

A rotary varifocal mechanism driven by ultrasonic motor was designed to remedy the shortcomings of a traditional varifocal mechanism in moving along the axial or radial directions,such as large occupation space, complicated configuration, long time consumption, low control precision, and the lack of self-locking function.This new varifocal mechanism has the advantages of the small space, simple configuration, short time for zoom completed, high control precision of rotating angle, strong repeatability, and self-locking function. The results of 100 shutoff characteristics of repeatability experiments show that the longest and the shortest shutoffs are 0.756 ms and 0.748 ms,respectively, when the average rotation speed is 150 r/min. Therefore, the maximum error of the shutoff time is 0.008 ms, the largest rotating angle error of the rotary varifocal mechanism is 0.432′,and the largest angle error displacement in the imager is less than 0.015 mm.These data can meet the system requirement.

By using the self-manufactured special processing equipment, the inner frame of a unmanned airborne optoelectronic stabilization platform is fabricated by the aluminum matrix composites with high volume fraction (55%～57%) SiC particles based on a pressureless infiltration technology. Benefiting from the composite's good mechanical properties, such as ultra-high modulus (the Young’s modulus is 213 GPa and the specific modulus is approximately three times of those of Al, Ti, and steel), low thermal expansion coefficient and very high thermal conductivity(235 W/m·K), the inner frame has decreased the maximum deformation by 60% and increased the fundamental frequency by 65% as compared with those of aluminum alloy materials,respectively. Therefore, a significant lightening effect is achieved and the thermal control load is also reduced. The test result indicates that the stable accuracy of the system achieves 20 μrad. The research applies the SiC/Al composites to airborne photoelectric platforms for the first time,which makes a effective exploration for the new aviation material's application.

The traditional image restoration algorithms based on a Hopfield neural network are unable to compress the noise and protect the details at the same time. In order to solve the problem,a new algorithm based on the modified Hopfield neural network with a continuous state change and the wavelet domain Hidden Markov Tree (HMT) model is presented. The wavelet domain HMT model is utilized as the prior information about the statistical relationship between the two image wavelet coefficients, and is introduced into the neural network model by a regularization term. The final restoration image is obtained by using the energy convergence property of the Hopfield neural network. Furthermore, a highly-parallel weight matrix determination algorithm is proposed,and then the weight values are computed batch by batch through the operation to the pattern images to avoid the multiplication of large scale matrices. Experimental results demonstrate that the visual quality of the restoration result is improved evidently for either real images or artificial images, and the Improved Signal to Noise Ratio(ISNR) is improved more than 0.3 dB compared to that of the traditional algorithms. The objectives of compressing the noise and protecting the details are achieved at the same time.

Aiming at a large amounts of computation existing in attitude measurements, a new method of 2-D object attitude measurement based on a covariance matrix is presented. Firstly,an image is segmented by the threshold and the center of an object is extracted. Then,the covariance matrix of the object is computed and decomposed by a orthogonal decomposition,and the elliptic equation defined by the covariance matrix is gotten. Finally,the lengths and orientations of both axes are calculated to obtain the scale change and rotation between the two images. The attitudes of objects in 256 pixel×256 pixel images are calculated with a log-polar algorithm and the presented algorithm respectively. The experimental results show that the angle error is within ±1°, and the scale error is within ±2% with proposed method,which is superior to those computed by the log-polar method, while the computation time is only 1/16 that of the log-polar method. The presented method can calculate the rotation and scale change fast and accurately, and can meet the requirement of real-time processing.

In order to detect circles automatically and to obtain the parameters in images precisely, a method to measure circles in industrial CT images was developed. Firstly, the sub-pixel edge of an image was detected based on a Facet model. Then, a method for calculating the existence probability map of circles and its defects were analyzed. To overcome the defects of long-time calculation and memory consumption, the present method made sure the potential range of the center of a circle and the stored message, which met the required numerical values in a chain. Finally, the circles were detected based on the improved method, and the circle parameters were calculated with Least Square Algorithm(LSA). The method was applied to measure an image with 10 circles obtained from an industrial CT system with the spatial resolution of 2.0 lp/mm. The results show that this method has greatly improved the calculation rate, and the measurement accuracy for circles is better than 0.5%. It can satisfy the measurement requirements of the circles for the higher speed, higher precision and non-contact.

In consideration of the motion blur and defocus blur of images, a robust bispectrum-based method is proposed to estimate the blurred parameters in noisy images. Firstly, the bispectrum of a blurred standard test image is calculated. Then,the curve fitting is used to obtain the functional relationship between the statistical characteristics in bispectrum and the degraded parameters. Finally, the BP neural network trained by the above mentioned functional relations can identify the parameters in point spread function in other noisy images. The experimental results show that the proposed method is effective for defocus and motion images in certain ranges. When SNR is 25 dB，the obtained tolerance of blurred parameters is less than 0.5 pixel.

A video de-noising method based on the 3D Wavelet Transform and Block Context Model(3DWTBCM) is proposed according to the strong correlation between the two frames of video sequence. On the basis of the characteristics of the coefficients in 3D wavelet domain and noise distribution, wavelet coefficients are partitioned into subblocks firstly in the light of local relativity of these coefficients and then the Context model is used in the corresponding subblocks. The wavelet coefficients in each block are divided into several parts by means of their energy distribution in the 3D Context model and each part is estimated by its independent energy distribution.Finally, suitable thresholds are obtained. Experimental results show that 3DWTBCM achieves better de-noising performance than hierarchical 2D de-noising methods and its PSNR is improved more than 0.5-1.2 dB on average in comparison with those of common 3D de-noising methods. In terms of visual quality, 3DWTBCM can effectively preserve the video detail while de-noising the wavelet coefficients and especially can provide video frames with rapid movements and more textures.

To solve the transmission and storage problems resulting from massive hyperspectral remote sensing data, a lossless compression algorithm based on the optimal recursive bidirectional prediction for hyperspectral images is presented. Different compression models for each band are chosen according to their spectral correlation factors. If the spectral correlation factor is less than 0.9, the bzip2 compression model is chosen. Otherwise, the single band optimal previous prediction is performed on the reference band and the optimal recursive bidirectional prediction is performed on the non-reference band.Furthermore, the residual images are coded by JPEG-LS. The algorithms designed in this paper has been applied to the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data,the result shows that the average compression ratio is 3.217, which is 0.09-1.374 higher than those from other lossless compression algorithms. This method is fast and works efficiently, so it can be widely used in practice.

It is valuable to fuse a Green Fluorescent Protein (GFP) fluorescence image and a corresponding phase contrast image for the research of the protein function and the localization of sub-cellular structures. With the aim to eliminate the false images come from the fusion of fluorescent images and phase contrast images by the multi-scale fusion algorithm based on the ARSIS concept in remote sensing images, a variable-transparency concept is proposed.A set of functions are designed based on visual effects. Then, each pixel is assigned a multi-scaled transparency,and original images are synthesized from the results of a Stationary Wavelet Transform (SWT). Furthermore, 30 groups of images are used to estimate parameters involved in the function set and then 117 groups are assessed by means of qualitative tests. Quantified indexes related to the fused product and original images, such as the quality index Q and the high frequency correlation coefficient HPCC, are calculated for inside and outside of the fluorescent area, respectively. The experimental results demonstrate that compared with common algorithms, including the transparency method, chessboard method and the SWT substitution method, the proposed algorithm can keep the interactive user-transparency and improve the definition of fused products while reducing the effect of the dark background of fluorescent images.

Compound Light Scattering Materials(LSMs) with polystyrene(PS) as the light scattering agents and Polymethylmethacrylate(PMMA) as the matrix were studied.The relationship between the haze and transmittance of samples and the amounts of agents was analysized for adjusting and controlling the light scattering properties of polymer materials which took the PMMA as the matrix.The results show that LSMs can be obtained with only a small amount of PS dispersed in PMMA. Experimental results also show that the transmittance of LSMs is 80% provided the content of PS is 1%. The haze could be improved from 50% to 80% with the aid of PMMAPS and the PMMAPS is able to increase the haze of LSMs by improving the compatibility between PMMA and PS. Therefore, LSMs with high haze and transmittance can be achieved by adjusting the amounts of PS and PMMAPS.