The space-based photoelectric imaging system has a great effect on recent high-tech local wars.However,the importance and inherent frangibility of the space-based photoelectric imaging and remote sensing device make problem of safety and protection more serious.In this paper, frangibility and manifold threats against space-based photoelectric imaging and remote sensing device, such as various plat- forms based anti-satellite laser weapons, kinetic kill vehicles, high power microwave weapons, are presented. In allusion to these threats, several defend technology, countermeasure and corresponding methods including space-based self-protection warning, multi-spectral artificial target, multi-spectral camouflage and smoke interference, photoelectric sensor reinforce, increasing the ability of flexibility of photoelectric imaging platform, carriage of self-protection weapons and so on, are analyzed, in which up to date technologies of laser radiation for space-based photoelectric imaging sensor protection, for example liquid crystals for protection,are emphasized. Some advice for new concept and low cost defend technology development are presented.

The forming pro cess and screening characteristics of red phosphorus smoke were elaborated. The mass extinction coefficients and granularity distribution of red phosphorus smoke to 10.6μm laser emission with two kinds of incident power were tested in a smoke to laser of chamber. The absorption efficiency factors, scattering efficiency factors and extinction efficiency factors of a single particle of red phosphorus smoke to laser of 10.6μm were calculated according to Mie scattering theory in far-infrared band. By the experiments, the average extinction coefficient of red phosphorus smoke to 0.552 W is 0.6027m^2/g and to 1.032 W is 0.5739 m^2/g. The average diameter of the smoke particles is 2.47 μm when the smoke formed 5 min. By the analysis, the extinction ability of red phosphorus smoke to 10.6μm laser emission depends upon the absorption effect. The mass extinction coefficient decreases while the smoke concentration increases. Under the same condition, the extinction coefficient of the smoke to 10.6μm laser emission will decrease when the power of incident laser emission increases or the air relative humidity decreases.

Identification of laser menaces is an important aspect in laser warning and data disposing. The identifying method has direct effect on its veracity. Based on the fact that technique parameters of laser signal have some fuzzy characters in presenting menaces ,a method of identifying laser menaces based on fuzzy decision is presented. The fuzzication mathematical models of laser technique parameters such as laser energy, wavelength,repeat frequency, and fuzzy decision rules library of identifying laser menaces are built, which are set up by using fuzzy decision theory. Professional system of fuzzy decision is designed. Using different kinds of sensors in the laser warning system, parameters such as laser orientation, wavelength,repeat frequency, and characteristic of pulse are acquired. In virtue of the professional system of fuzzy decision, the type of the laser menaces is identified. Simulation result shows that the method can exactly identify the laser menaces , offer references for the study on the other data fusion of and has some practical value. The method can laser warning.

Deception jamming methods such as passive positive deviation jamming , active positive deviation jamming and active negative deviation jamming etc on laser rangefinders and corresponding technical requirements are systematically discussed. Meanwhile the jamming effect evaluation model of passive delay fiber jamming system is established with its technical feasibility parameters calculated, and a conclusion is drawn that the passive delay fiber jamming system is practical.Available and potential countermeasures of laser rangefinder are also presented.

Infrared smoking screen is an effective way to confront the infrared imaging anti-ship missile, for researching on the theory of the smoke screen confronting the infrared imaging anti-ship missile, the motion models of the warship, screen smoke and missile are given, the judgement method of the smoke＇s interfere effectiveness is discussed from the point of SNR of missile influenced by smoking screen＇s thickness,the infrared smoking screen confronting the infrared imaging anti-ship missile is dynamically simulated and the principle and the means of the arrangement about the smoke and elusion of the warship are derived from simulation, the simulation conclusions are of great value to the tactics use of the screen smoke confronting the infrared imaging guided missile.

Predominance of imaging laser radar is introduced in guidance system, A plan that simulation with heterodyne imaging laser radar guidance system is presented, then its four applying important sections are analyzed： optics, data processing, general library, stabilization and tracking. Combining influence of different ambient and device performance parameters on this system, modules of every section are analyzed and multifold mathematical models are presented. It is indicated that further functions of this system are required in the end.

An analytical expression of optical breakdown threshold for water has been abtained after simplifying the rate equation of free electron experimentally measured breakdown threshold picosecond and femtosecond laser pulses in the density.The calculating results have been compared with of pure water and impure water induced by nanosecond, visible and near-infrared. For nanosecond laser pulses, the generation of free electrons in distilled water is initiated by multiphoton ionization but then dominated by avalanche ionization. For shorter laser pulses, multiphoton ionization becomes more important, and the effect of collision and recombination on breakdown threshold losses gradually during breakdown. A good quantitative agreement is achieved between calculated and measured results.

Maximum range is one of the major parameters of pulse laser range finder, Several common measurement methods are analyzed. A novel method combining outdoor light extinction ratio with indoor time sequence gain coefficient ratio is proposed, For two pulse laser range finders, outdoor light extinction ratio, indoor time sequence coefficient and maximum range are measured and compared. The results and error analysis are given. The results prove that the maximum range of the pulse laser range finder whose operating wavelength is 1.06μm and 1.54μm could be measured accurately, and it is hardly effected by weather condition and target properties, nor is effected by time sequence gain circuit. The method has high accuracy, repeatability and serviceability . By this method, other major parameters of the pulse laser range finder such as ranging accuracy, gating range, gating accuracy and range resolution can also be measured.

To minimize the elements inserted in the cavity of 2μm band tunable laser and reduce the cavity loss, a special designed prism based on the disperse property of LiNbO3 crystal was used as tuning and Q-switching element . Two faces cut at Brewster＇s angle make the prism work well as tuning element. In a flash-lamp pumped Cr-Tm：YAG 2μm laser with the LiNbO3 prism, active Q-switching operation was realized at room temperature, while the tuning range of 1.95 -2.08μm was obtained with the prism. The repetition rate of the Q-switched laser was 1-5 Hz. The experimental result shows that the Q-switching and tuning method is valid.

Mode-locking fiber laser has many merits such as compactness, stability and good mode. Using a novel transmitted type semiconductor saturable absorber mirror （SESAM） as an output coupler, a Yb3+ doped double-clad Q-switching mode-locking fiber laser is constructed . The shortest period of the envelope of the Q-switched mode-locking is about 500 ns with a repetition rate of 110 kHz and an average output power of 45 mW. The repetition rate of the mode-locking pulse train is 26.7 MHz. The setup of mode-locking laser using transmission type SESAMs is simple and easy to adjust, than that using reflection type SESAMs. So it＇s convenient for insert dispersion compensation elements to achieve femtosecond pulse mode-locking laser.

On the basis of analysis on the stadia equation of the low light level （LLL） night vision system, the possibility is demonstrated that using pulse infrared laser array can improve the stadia of the LLL night vision system. The pseudo random laser enhancement technique is put forward to handle the limitation that the laser assistant system is easy to be detected. The pseudo random coding theory is studied, the control circuits of pseudo random laser modulating and image capturing synchronously are designed. The pulse infrared laser assistant system is established, many experiments and some observation evaluation on the experiments have been carried out. Some good results are obtained.

The aerodynamic flow about an aircraft or other vehicles in flight has a marked influence on the performance of the onboard optical sensor system. Missile interceptor seeker windows undergo significant heating and stress during supersonic flight. These effects lead to window and flow field distortions that can significantly degrade the image quality on the seeker. A method is developed to predict the optical transmission of the turbulence flow field. The approach and some computer simulation results are presented.

To solve the problem of the fractional of the laser energy absorption in solid output windows of conventional gas lasers, the free-vortex aerodynamic window is designed based on the aerodynamic theory and numerical simulation, The position and width of the diffuser＇s intake are studied by means of numerical simulation of the overall flow field in this paper. The appropriate width and position are obtained. At last, the overall flow of the free-vortex aerodynamic window is calculated and discussed using the finite element method, the calculation results show that the design is reasonable.

With the maturing design of micro electrical mechanism systems （MEMS） , the metrology for MEMS is becoming the hot research in the micro system technology. In this paper, the summodified-laplacian （SML） focus measure and depth estimation method are used to measure the tip deflection of a thermally actuated polymer micro robotic actuator. Ten one underwater images of the micro actuator working at 42℃ have been used to illustrate the idea of measuring the tip deflection using optical focus method. The results can be used for metrology of MEMS. Optical focus method is used to measure the tip deflection, which can act as a feedback input to the actuator. Then, an accurate control of the motion of actuator can be achieved.

Because of the influence of nature meteorological condition, background environment and the structure of target, the detection of weak and small targets in infrared image is one of the difficulties among image targets detection and identification.A new small target detection method is presented,in which the infrared image intensity surface is well fitted by the least square support vector machine （LS- SVM）, and then the maximum extremum points are detected based on the fitted intensity surface. It is decided whether the extremum point is a target position or not by comparing the gray level of the point with the average gray intensity of its local area. The second order directional derivative operators are deduced from the LS-SVM with the radial basis kernel function, as an example. The computer small target detection experiments are carded out for the real and simulated images. Experimental results demonstrate that the proposed algorithm is robust and efficient.

It is an important task to detect the small targets in a sequence of images against complex background. An algorithm of small target detection based on pattern lateral inhibition is proposed.Small target detection in complex background is considered as a problem of finding the special patterns in similar patterns. The special patterns are enhanced with the Lateral Inhibition network. At the same time,multi-level processing is presented to improve treatment effects.The performances of several traditional filters and the method in this paper are compared.Two defininitions of SCR and SCR gain are defined to evaluate the performance of the approach Experimental results show that the approach proposed is effective in detecting the small targets in clutter.

According to different imaging system,moving point target detection in image sequences can be divided into two categories：moving point target detection in infrared image sequences and moving point target detection in visible image sequences. Most of existing arithmetics are aimed at infrared image sequences,so the main purpose of this article is to look for a new detection method which can be used in the two kinds of image sequences. A new arithmetic of moving point target detection for cloudy sky background is proposed.In the stage of background suppressing, a method that combines high-pass filter with mathematic morphology filter is applied. Based on the idea of TBD, three frames are conjointed to accomplish target segmentation. Track energy cumulation is used to detect the targets.Theoretic analysis and simulation results prove that this arithmetic is simple and easy to be realized, it can be used in infrared image and visible image ,furthermore it has no restriction on target＇s velocity and direction.

For the real-time detection of small target in the IRST systems, a temporal-spatial fusion filtering algorithm is proposed. The algorithm suppresses background and enhances targets by morphologic Tophat transform in spatial, and detects moving target by improved frame difference method in temporal. After the fusion image segmentation of the temporal and spatial processing result, the real target can be detected by the relation of the possible target＇s position in adjoining frames on the basis of the target＇s moving continuity and regulation. The algorithm entirely considers the characteristic that the small moving target can be detected in temporal and spatial, it enormously increases the target＇s SNR after the temporalspatial fusion enhancement. The detecting results of the true airplane＇s infrared image sequences in cloud background show that the algorithm can be more effective to detect low SNR moving small targets in complex background and reduce false alarm. The algorithm is easy to realize in hardware and can be applied effectively in the real-time target detection of the IRST systems.

Before the infrared target is recognized by BP neural network,the recognition precision will be low and the structure of BP neural network will become complex if samples＇ data is not preprocessed and features are not extracted. In the paper, the principal componenet analysis is used to solve these problems.This method can extract main factors that explain the targets＇ sample and these factors are not correlative each other which can well satisfy the features optimization. The study result indicates that while the processed data is put into the neural networks,the precision of recognition is improved, the training time is reduced,and the structure of neural networks becomes simple.The innovation of the paper is two common methods are combined to recognize the infrared target. Firstly the principal component analysis is used to process the sample data,then the BP neural network is used to recognize the target.Compared with the traditional simple method,it improves the precision, furthermore reduces the calculation.

An optimized method is proposed to estimate the turbulent point spread functions （PSF） by using two consecutive short-exposure images in a sequence of turbulence-degraded images, in which the principle of constraint optimization has been applied in the process of restoration. The scheme of preserving peaks of the PSF has been adopted in the estimation of the PSF values, which is in agreement with the property of turbulent PSFs being stochastic changeable with some complex peaks. The problem of calculating the PSFs＇values has been boiled down to optimization estimation based on relax iterations. The discrete values of the PSFs can be estimated by minimizing the critical function, consequently the object image can be obtained. The restoration experiments show that the proposed algorithm is efficient with good restoration effect and fast speed.

The cross-entropy value illuminates the information difference between the template image and the real-time image on the average. In this paper, aiming at solving the problem of the radiation distortion and geometry distortion in the system of the photoelectric pod, the image matching tracking algorithm based on cross-entropy is proposed. Since the cross-entropy minimum rule is propitious to image matching with abundant information, the algorithm mentioned is provided with the very good antinoise properties, and the capability of resisting radiation distortion and geometry distortion.The results of simulation experiment show that this algorithm has steady matching tracking ability and well adaptability when radiation distortion happens. So it is a practical algorithm.

The detection and recognition of specific targets is one of key techniques of ATR. The recognition of a runway, as a specific ground target, is still an interesting research subject in the ATR. An algorithm of automatic runway recognition based on multi-scale linear object enhancement is presented according to runway characters of linear structure and high intensity. Experimental results show that the algorithm can enhance runway while restraining other objects of nonlinear structure and has better performance than the algorithm based on edge detection in the complicated background.

Edge detection has been an important domain in comprehension of image and computer vision, Its quality determines the result of subsequent analysis. Thus it＇s an important goal for people to find a kind of method that is insensitive to noise, precisely locates true edges and excludes false edges. In theory Canny operator is optimal in continuous domain for edge detection, but not optimal in discrete case, which may lead to inaccurate result. In order to solve the problem above, a good edge detection algorithm in discrete field is proposed. The smooth operator is inferred based on the Optimal Discrete Filter＇s theory, which can reduce the influence of noise, false edges and image error. The experimental result shows that the proposed method can achieve multi-scale edge detection and high SNR, satisfy the requirement for computer recognition. So it is a good edge detection method.

The influence of the variance of the presupposed measured error is analyzed briefly. A new method is presented on the basis of the on-line estimation for the variance of the measured error through spatial-temporal synthetical analysis. It can make full use of redundancy and complementary in- formation, which comes from the single sampled data of multi-sensors and the multi-times sampled data of single sensor, thereby, which improves the influence of modeling error caused by the shortage of prior information for the condition of observed. At the same time, utilizing the characteristic that filtering error covariance expresses filtering precision, the dynamic and reasonable distribution of the every sensor weight coefficient is accomplished. Finally,a new algorithm of multi-sensors fusion based on the variance of the measured error adaptive is given.Monte-Carlo simulation shows that this algorithm can obviously improve the efficiency of maneuvering target tracking.

SOPC is a flexible and efficient SOC design methodology which is developed by Altera Corporation. Small efficient infrared image processor can be developed with the technology advantage of SOPC. In the paper, an infrared image processor based on SOPC technology is discussed, which has realtime infrared image processing and display driving function. The processor mainly encompasses a nonuniformity correction module, a real-time image enhancement module and a display driver. A single SOPC chip EPXA4 of Altera Corporation implements the main function of the processor. Experimental results show that the infrared image processor based on SOPC has high real-time performance,small bulk and low power dissipation.

Germanate and fluoroaluminate glasses have potential applications as windows and dome in the field of middle-infrared （MID-IR）. In order to remove the residual water in germanate glass, some fluoride were added into the composition. Experimental results indicated that the content of OH group decreased with fluoride increasing. When the melting temperature was increased, the transmitting spectrum was obtained without absorption of hydroxyl. For fluoroaluminate glasses easily forming crystal dur- ing cooling, tellurium dioxide was doped into the fluoride glasses, the glass forming ability was improved and the glass could be easy to fabricate bulk. Meanwhile some physical and chemical properties of the two types of infrared material were reported.