This PDF file contains the front matter associated with SPIE Proceedings Volume 8196, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listings.

The launched space optical Remote Sensors, including the three generations of space film remote sensor, the space CCD remote sensor and the IRMSS for resources survey, the first generation CCD and IR remote sensor for disaster monitoring, the first generation CCD and IR camera for ocean monitoring, the related remote sensor in polar orbit and geostationary orbit for meteorological detection and forecasting, the first generation related remote sensor for deep space exploration, etc, are presented in detail in the paper. The related technologies, including system design technology, the lens technology, the FPA video technology, the manufacture technology, the AIT technology, etc, are also introduced in the paper. The Chinese great achievements in the field of space optical remote sensor are shown. The prospects on future development of the space serial optical remote sensors and the related technologies are made.

Current research on space-based exploration for the ionosphere needs more advanced technologies. Because the spectral signals in the ionosphere distributing basically in the farultraviolet waveband are very weak. Usual spectrometer structures and detectors such as CCD can't receive enough information. Based on this principle of atmospheric sounding, the imaging spectrometer prototype for ionosphere detection application was designed to solve the problem. This prototype consists of the telescope and the imaging spectrometer. The simple structure and small number of mirrors can help higher transmission efficiency be achieved and weak signals detection be implemented. The telescope is an off-axis parabolic mirror and the spectrometer is a modified Czerny-Turner spectral imaging system. Modified Czerny-Turner spectrometer contains a spherical mirror, a fixed plane grating and a toroidal mirror. By adjusting the incident angle to the collimating mirror and using toroidal mirror, coma and astigmatism were corrected well. We also optimize distances between the grating to the focusing mirror and the focusing mirror to the image plane to improve disadvantages of traditional Czerny-Turner structure. Designed results demonstrate that aberrations are substantially corrected, and high image quality can be obtained in broad waveband. The photon counting Wedge-Strip-Anode detector with micro-channel planes as the receiving plane is accepted for the instrument prototype. The other photon counting 2-D detector responding well for weak light such as Cross-Delay line detector and MAMA detector can also be used for detection. The calibration and performances testing system is made of a vacuum system, a deuterium lamp, a monochrometer and the instrument prototype. Results obtained from the experiment show that the spectral resolution is 2.4 nm and the spatial resolution is 80 μm. The other calibration experiments are running. The technology of the spectrometer prototype is important for the research and applications of ionosphere remote sensing.

A dosimeter for space ionization radiation field is developed, energy deposited in the sensitivity volume of ionization chamber induces an output current signal as weak as 10-¹⁴A, and the dynamic range of the signal is very high. Now, an ionization chamber is designed and a variable gain current feedback preamp module is designed for the weak output current amplification is connected to output of the ionization chamber anode. The amplifier module includes I-V converter with T shaped resistance net, zero correct circuit, low pass filter, voltage linear amplifier circuit, gain control circuit and voltage output circuit. A complete analysis of this current preamp with respect to its circuit structure, dynamic properties, its equivalent input noise and the temperature effect is given. The effects of stray impedances on the behavior of the current feedback preamp are taken into account and the techniques necessary to achieve an optimum stable electrometer, with respect to noise, Dc drift, leakage currents, are applied. Experiments show that the energy of dosimeter deposited in the sensitivity volume of ionization chamber induces an output current signal as weak as 10^-14A, the current preamp can detect weak current effectively with the range from 100fA to 10μA through switchable gain.

Determination of relative three-dimensional position and orientation between two reference frames can be solved by the pose measuring methods based on monocular vision model. Owing to the special T-shaped configuration, the definition of object rotational matrix in the terms of quaternion elements helped in representing the problem by six nonlinear equations from which a closed-form solution can be obtained for all the unknown parameters. The calculating formulas of elements in the rotational matrix were deduced from the coordinates of feature points in camera frame as well as the converting vector which was also introduced into the process acting as corrected term. An approximate pose could be found by the assumption of zero difference in depth of all points in camera frame, then the converting vector should be initialized by the third row of current rotational matrix. The principle of computing priority of the max value in quaternion expression was proposed to ensure the convergence of the iteration loop through which the final pose was achieved in a few iterations. Simulation experiments show the validity of the solution and analysis of the calculating precision was made in detail. The measuring orientation error would constringe with the reduction of distance from camera focus to target object and performance of the algorithm went well in short distance, while the deformation went larger with the increasing of errors caused by imprecise correspondence.

To solve the problem of thermal control coatings degradation in space environment, it is necessary to study coatings degradation law in simulated space environment, thus a radiometer design based on calorimetry was proposed for in situ measurement of thermal control coatings solar absorptance. The radiometer structure was designed according to the requirement of in situ measurement. By conducting thermal analysis on radiometer, the heat transfer equations were built and a calculation model based on transient thermal equilibrium was established by energy conservation principle. A SR107 thermal control coating was tested in isoperibol. The experiment result shows a within 3% relative error between the solar absorptance of SR107 and the coating calibration value, with a 5.24% measurement uncertainty. It validates the effectiveness of radiometer experiment and lays a foundation for further development of thermal control coating performance test.

A ringing effect often occurs in restored images, and its typical feature is that there are Gibbs-like oscillations in the neighboring areas of an image with sharp gray scale variations. The existence of the ringing effect causes it to be difficult for the restored images to be subsequently processed and some image quality evaluation methods to be invalid. In this paper, we studied several image restoration methods for diffraction-degraded remote sensing image: a Wiener filtering algorithm that is a simple and rapid image restoration algorithm, which is especially suitable for images without noise and with accurate PSF estimation and a small degree of blurring; an RL (Richardson-Lucy) algorithm that can gradually improve the image definition with an increase in iterations but the ringing effect becomes more and more significant; and a TV (total variation) algorithm that is a normalization algorithm based on noise and ringing suppression. We used multiple parameters to evaluate the restored images, including BDQ (block difference quality), GMG (gray mean grads), LS (Laplacian operator sum), and LE (large entropy), for which reference image are not required, as well as PSNR (peak signal noise ratio), SSIM (structural similarity), GRM(Gradient Ringing Metric) and HVSWGM (weighted gradient metric based on human visual system), for which reference image are required. The results show that the HVSWGM method is insensitive to the ringing effect occurring in image restoration and the evaluation result is completely consistent with a subjective evaluation result with a human visual system, and that many non-reference methods fail completely in assessing restored image with ringing effect, and only BDQ method is able to conform to subjective evaluation method to some extent.

In this paper, a real time method for detecting multiple dim targets in deep space background is presented and special attention is paid to occlusion handling. We matched the stars in tow continuous images to get their speed at first and found moving target pairs through speed in both images, a kalman filter whose equation was updated by the centroid was adopted to track the target. The star's area was used to judge occlusion, a two Gaussian mixture model was build using the pixels' gray value of fusing region and we used the predicted value which the kalman filter given to detect the target. The model's parameters were estimated using the expectation-maximization method and applied to separate the target and the star as well as computing the precise centroid. Extensive experiments on real images sequences show that the proposed approach could effectively meet the requirements of the real-time detection with a low false alarm rate and a high detection probability, simulation results show that it can also create a accuracy centroid when occlusion happens.

The special topography of mountain terrain will induce the retrieval distortion in same species and surface spectral lines. In order to improve the research accuracy of topographic surface characteristic, many researchers have focused on topographic correction. Topographic correction methods can be statistical-empirical model or physical model, in which the methods based on the digital elevation model data are most popular. Restricted by spatial resolution, previous model mostly corrected topographic effect based on Landsat TM image, whose spatial resolution is 30 meter that can be easily achieved from internet or calculated from digital map. Some researchers have also done topographic correction based on high spatial resolution images, such as Quickbird and Ikonos, but there is little correlative research on the topographic correction of CBERS-02B image. In this study, liao-ning mountain terrain was taken as the objective. The digital elevation model data was interpolated to 2.36 meter by 15 meter original digital elevation model one meter by one meter. The C correction, SCS+C correction, Minnaert correction and Ekstrand-r were executed to correct the topographic effect. Then the corrected results were achieved and compared. The images corrected with C correction, SCS+C correction, Minnaert correction and Ekstrand-r were compared, and the scatter diagrams between image digital number and cosine of solar incidence angel with respect to surface normal were shown. The mean value, standard variance, slope of scatter diagram, and separation factor were statistically calculated. The analysed result shows that the shadow is weakened in corrected images than the original images, and the three-dimensional affect is removed. The absolute slope of fitting lines in scatter diagram is minished. Minnaert correction method has the most effective result. These demonstrate that the former correction methods can be successfully adapted to CBERS-02B images. The DEM data can be interpolated step by step to get the corresponding spatial resolution approximately for the condition that high spatial resolution elevation data is hard to get.

The simulation of space-based visible surveillance images can offer technical support to the index argumentation, scheme design and ground-tests of spatial optical system. Based on the analysis of the space-based visible surveillance principle, this paper establishes the simulation framework of space-based visible surveillance images, as well as its workflow, and simulates the images of the celestial background and space objects respectively with OpenGL. Firstly, concerning its visual features, the celestial background can be divided into point objects and surface objects. The rendering methods based on OpenGL for both objects are given and the basic space background rendering workflow is also established. The 14-magnitude stars are rendered in the simulation of celestial background which can satisfy the need of the space-based visible surveillance. Secondly, this paper calculates the orbital elements of the objects through utilizing TLE data and SGP4/SDP4 model and obtains the positions of them in the CCD through coordinate transformation. Simultaneously, the brightness model is built up in combination with the distribution features of the space objects' surface and the simulation of the space objects' images is realized with the attainment of the brightness in the CCD through greyscale conversion. Finally, the space-based visible surveillance images are generated by overlapping the star background and the objects' images. The fidelity of the simulation images is almost identical to the images which are obtained by the SBV camera, which convincingly proves that the proposed rendering method can effectively simulate the celestial background and the target images when observed with space-based visible camera.

A real-time infrared mixed targets detection system is designed to detect targets of uncertain number or sizes in a sky background during the real project. The system takes Digital Signal Processor (DSP) as its main processor and takes Field Programmable Gate Array (FPGA) as a preprocessor. As to the problem of mixed targets of different sizes, the method adopts degrading resolution of image to reduce the range of target size. To suppress the background and enhance the SNR of image, weighted mean-value filtering operations are used. To segment the image, a self-adaptive threshold segmentation approach is adopted. Finally, based on motion trajectory consistency, false targets are eliminated and real small targets are reserved through improved pipeline filter. The experimental results indicate that the method can satisfy the real- time requirement of infrared target detection system.

Small visible optical space targets detection is one of the key issues in the research of long-range early warning and space debris surveillance. The SNR(Signal to Noise Ratio) of the target is very low because of the self influence of image device. Random noise and background movement also increase the difficulty of target detection. In order to detect small visible optical space targets effectively and rapidly, we bring up a novel detecting method based on statistic theory. Firstly, we get a reasonable statistical model of visible optical space image. Secondly, we extract SIFT(Scale-Invariant Feature Transform) feature of the image frames, and calculate the transform relationship, then use the transform relationship to compensate whole visual field's movement. Thirdly, the influence of star was wiped off by using interframe difference method. We find segmentation threshold to differentiate candidate targets and noise by using OTSU method. Finally, we calculate statistical quantity to judge whether there is the target for every pixel position in the image. Theory analysis shows the relationship of false alarm probability and detection probability at different SNR. The experiment result shows that this method could detect target efficiently, even the target passing through stars.

The detecting technology is very important for the discovery of space objects. The target is submerged by the complex background noise which is the environment of outer space and the device produced. The difficulty of the detection is increased. The detect system mainly has three kinds of working patterns including the fixed tracking pattern, the fixed star tracking pattern and the target tracking pattern. Theses pattern differences perform as moving target in moving background, moving target in static background and static target in moving background in the images. We bring up a new framework for detecting target in three kinds of working patterns based on the feature stability difference. The first step is preprocess. Secondly, we extract features from image sequence. Then we construct a stability function about features for every pixel. Finally, we can detect the position of target according to the value of stability function, then map the position of target in the feature domain to the original image, and search in original image for the accurate centroid of the target. Qualitative and quantitative results prove that the proposed algorithm has strong anti-noise performance and fit for kinds of working pattern of detection system for target detection conveniently.

Spacecraft would be expected to encounter diverse extreme environmental (EE) conditions throughout their mission phases. These EE conditions are often coupled. Star tracker is a high accurate 3-axis attitude measuring instrument used in various spacecrafts. In this paper, an effective scheme to the thermal/optical analysis in optical system of star sensor was described and the concept of thermal optical analysis of star tracker optical system was introduced in detail. Using finite element analysis (FEA) and ray tracing, we can study the relationship of optical properties of optical systems and optical system's temperature distribution . A lens system configuration having six uncemented elements was discussed. The lens system was a 56mm EFL, which was different from common lens used in imaging system that this lens system was required to have a high resolving power in design thoughts. It was designed to determine the attitude of space platform by detecting and mapping the geometric pattern of stars. Based on this system, the FEA models of the optical system were established for temperature distribution calculation and for thermal-elastic structural deformation analysis respectively. Using the models, the steady-state temperature distributions of the tracker were simulated. The rigid body displacements of the optical components under homogeneous temperature changes and certain temperature distributions were derived out. It is convenient to use Zernike polynomials as the data transmission between optical and structural analysis programs. Here, Zernike polynomials and their fitting method are used as an example to determine the thermal induced optical degradations of the optical system.

Pulse position modulation (PPM) provides a means of using high peak power lasers for transmitting communications signals from planetary spacecraft to earth-based receiving stations. In this paper, we use avalanche photodiode (APD) as the receiver, on the basis of analyzing channel model of atmospheric laser communication, do deeply researches on the performance of PPM optical pulse system that influenced by timing error, draw a conclusion on the relation between frames error rate of strong, weak turbulent environment and normalized timing error respectively. In addition, on the condition of existing timing error in the system, we obtain satisfactory results by simulation on how the change of parameters including flicker index, APD average gain, level of PPM modulation influence the performance of PPM optical pulse system.

Clustering analysis is currently one of well-developed branches in data mining technology which is supposed to find the hidden structures in the multidimensional space called feature or pattern space. A datum in the space usually possesses a vector form and the elements in the vector represent several specifically selected features. These features are often of efficiency to the problem oriented. Generally, clustering analysis goes into two divisions: one is based on the agglomerative clustering method, and the other one is based on divisive clustering method. The former refers to a bottom-up process which regards each datum as a singleton cluster while the latter refers to a top-down process which regards entire data as a cluster. As the collected literatures, it is noted that the divisive clustering is currently overwhelming both in application and research. Although some famous divisive clustering methods are designed and well developed, clustering problems are still far from being solved. The k - means algorithm is the original divisive clustering method which initially assigns some important index values, such as the clustering number and the initial clustering prototype positions, and that could not be reasonable in some certain occasions. More than the initial problem, the k - means algorithm may also falls into local optimum, clusters in a rigid way and is not available for non-Gaussian distribution. One can see that seeking for a good or natural clustering result, in fact, originates from the one's understanding of the concept of clustering. Thus, the confusion or misunderstanding of the definition of clustering always derives some unsatisfied clustering results. One should consider the definition deeply and seriously. This paper demonstrates the nature of clustering, gives the way of understanding clustering, discusses the methodology of designing a clustering algorithm, and proposes a new clustering method based on relation chains among 2D patterns. In this paper, a new method called relation chain based clustering is presented. The given method demonstrates that arbitrary distribution shape and density are not the essential factors for clustering research, in another words, clusters described by some particular expressions should be considered as a uniform mathematical description which is called "relation chain" emphasized in this paper. The relation chain indicates the relation between each pair of the spatial points and gives the evaluation of the connection between the pair-wise points. This relation chain based clustering algorithm initially assigns the neighborhood evaluation radius of the points, then assesses the clustering result based on inner-cluster variance of each cluster while increasing the radius, adjusting the radius properly and finally gives the clustering result. Some experiments are conducted using the proposed method and the hidden data structure is well explored.

Due to the insufficient employment of the correlation among wavelet coefficients, existing significance coding methods can't reduce entropy redundancy efficiently. In order to solve this problem, a significance context model based on intraband and interband correlation is proposed. The model uses neighbor coefficients in the same subband and a parent coefficient in the lower subband as context to predict the current coding coefficient. Neighbor weight and parent weight are defined to distinguish prediction effect of neighbor coefficients and parent coefficient. For neighbor coefficients, different neighbor weight values are assigned according to their directions and bit-planes. Parent coefficient as a significant coefficient has the same prediction effect on either the current bit-plane or above bit-plane, so it is assigned only one weight value. With classifying the coding coefficients according to neighbor weight and parent weight, and merging the contexts with similar probability distribution, the final context classification scheme fitting for most remote sensing images is acquired. Experimental results have shown that the proposed significance context model is prior to the JPEG2000's. It can employ correlation among wavelet coefficients more sufficiently, and remarkably improve the compression performance.

Electric field abnormal is one of the most important earthquake precursor phenomena in the ionosphere. The ionosphere electric field abnormal has the characteristic of wide frequency band (frequency range from DC to several MHz), which is suitable to be detected by the double-probe spaceborne electric field sensor (DSEFS). The DSEFS is composed of four sensing probes, four booms outside of the satellite and one signal acquisition and processing system (SAPS) inside the satellite. The four booms are used to set the four probes away form the satellite platform and form a tetrahedron in the space. The plasma potential around the probe is coupled to the probe though equivalent resistor and capacitor in parallel, which is the result of the probe charging. The plasma potential is acquired with a preamplifier with very high input impedance in the probe. In order to insure the detection precision, the value of equivalent resistor can be adjusted with a bias current provided by the SAPS. The probe potential is further acquired and processed by the SAPS to form three dimensional orthogonal electric field detection results. In order to insure the detection precision of the plasma electric field, the Spacecraft and Plasma Interaction System (SPIS) simulation software was used to simulate the interaction between satellite, sensor probes, booms and surrounding plasma. There are two major contributions in the paper. Firstly the layout of the sensor probes outside the satellite was optimized to reduce the influence of wake effect. Secondly, the fixing mode between the boom and satellite was optimized to reduce the influence of satellite potential change on the probe charging characteristic.

Double-probe spaceborne electric field sensor (DSEFS) was used to detect the ionospheric electric field abnormal of earthquake precursor. The DSEFS is comprised of four probes and four booms outside the satellite and one signal acquisition and processing system inside the satellite. Four cylindric electrodes called C2 of the probes were used to connect the booms and the probes. The length of C2 is one of the most important geometric parameter need to be optimized to ensure the detecting precision of DSEFS. In order to understand the operation of the electric field probes and optimize its performance, Spacecraft Plasma Interaction System (SPIS) software and DEMETER detected data were used to study the influence of C2 length on the DSEFS detection precision. The simulation results showed that when the C2 length is bigger than 2 Debye lengths, the influence of the boom potential had almost no disturbance on the DSEFS probes. In the case of short C2 length, when the boom had a potential which is positive with respect to the probes, the local electric field between the boom and the probe was the dominant factor, the probe collected currents monotonously increased with the increasing of C₂ length. When the boom has a negative potential with respect to the probe, the probe collected current did not monotonously increased with the increasing of C2 length, when the length of C2 is relatively short (less than 20cm), the effect of boom sheath was the dominant factor, the probe collected current increased with the increasing of C2 length; when the length of C2 is larger than 20cm, the local electric field became the dominant factor, the probed colleted current decreased with the increasing of C2 length. The computer simulation result provided good guidance on optimization design of the C2 length of DSEFS.

In the space target exploration with narrowband radar, targets with high-speed go through several range cells in the observation period which makes it more difficult to get each target's power coherently accumulated for target detection. In addition, for multi-target detection with different velocity, the range migration amount will not be equal. This is another problem for small target detection. In this study, novel multi-target detection with narrowband radar system is proposed. The Keystone transform firstly be used for correcting the range migration in a pulse repetition frequency (PRF). Then the fold factor of the strongest target can be estimated through Sparse Radon transform and compensates the corresponding phase term, following a quadratic phase term be compensated and at last the energy of the strongest target can be accumulated effectively by Fourier transform. The Clean technique is applied to the case of multi-target detection. The proposed algorithm is verified by simulation results.

In order to meet the requirements of lunar based astronomical observation which includes three different observing modes: specific celestial body observations, calibration observations, sky surveys, the two Axes gimbal is designed to guarantee the telescope can point and listen to a exact point in the sky. Due to the harsh environment on the moon and space payload weight limit, based on lightweight design method, such as structure optimization and rational material selection, the weight of gimbal is greatly reduced without decrease of rigidity and strength. In addition, because of the usage of external rotor mechanism for vertical shaft, the system's first order mode along the emission direction is greatly improved. On the other hand, The shaft with one fixed end and another free end is adopted to reduce the deflection between its two larger span ends. Furthermore, the shaft stuck at both ends due to temperature changes on the moon is eliminated by rational determining the clearance of deep groove ball bearings. Experiments show that, the system's first order resonant frequency can reach 81HZ, and the mechanism works well from -25 °C to +60 °C without stuck phenomenon occured. So, because of the adoption of approaches mentioned above, the mechanism has good mechanical properties, such as high reliability and light weight.

In the conventional method, the structural parameters of primary mirror are usually optimized just by the requirement of mechanical performance. Because the influences of structural parameters on thermal stability are not taken fully into account in this simple method, the lightweight optimum design of primary mirror usually brings the bad thermal stability, especially in the complex environment. In order to obtain better thermal stability, a new method about structure-thermal optimum design of tracking primary mirror is discussed. During the optimum process, both the lightweight ratio and thermal stability will be taken into account. The structure-thermal optimum is introduced into the analysis process and commenced after lightweight design as the secondary optimum. Using the engineering analysis of software ANSYS, a parameter finite element analysis (FEA) model of mirror is built. On the premise of appropriate lightweight ratio, the RMS of structure-thermal deformation of mirror surface and lightweight ratio are assigned to be state variables, and the maximal RMS of temperature gradient load to be object variable. The results show that certain structural parameters of tracking primary mirror have different influences on mechanical performance and thermal stability, even they are opposite. By structure-thermal optimizing, the optimized mirror model discussed in this paper has better thermal stability than the old one under the same thermal loads, which can drastically reduce difficulty in thermal control.

The type of Field Programmable Gate Arrays (FPGAs) technology and device family used in a design is a key factor for system reliability. Though antifuse-based FPGAs are widely used in aerospace because of their high reliability, current antifuse-based FPGA devices are expensive and leave no room for mistakes or changes since they are not reprogrammable. The substitute for antifuse-based FPGAs are needed in aerospace design, they should be both reprogrammable and highly reliable to Single Event Upset effects (SEUs). SRAM-based FPGAs are widely and systematically used in complex embedding digital systems both in a single chip industry and commercial applications. They are reprogrammable and high in density because of the smaller SRAM cells and logic structures. But the SRAM-based FPGAs are especially sensitive to cosmic radiation because the configuration information is stored in SRAM memory. The ideal FPGA for aerospace use should be high-density SRAM-based which is also insensitive to cosmic radiation induced SEUs. Therefore, in order to enable the use of SRAM-based FPGAs in safety critical applications, new techniques and strategies are essential to mitigate the SEU errors in such devices. In order to improve the reliability of SRAM-based FPGAs which are very sensitive to SEU errors, techniques such as reconfiguration and Triple Module Redundancy (TMR) are widely used in the aerospace electronic systems to mitigate the SEU and Single Event Functional Interrupt (SEFI) errors. Compared to reconfiguration and triplication, scrubbing and partial reconfiguration will utilize fewer or even no internal resources of FPGA. What's more, the detection and repair process can detect and correct SEU errors in configuration memories of the FPGA without affecting or interrupting the proper working of the system while reconfiguration would terminate the operation of the FPGA. This paper presents a payload system realized on Xilinx Virtex-4 FPGA which mitigates SEU effects in the internal FPGA by implementing scrubbing strategy and thus improve the reliability of the whole system.

In this paper, structure analysis with finite element method is carried out for a 4-m class honeycomb primary mirror. The mirror's baseline support system consists of 60 axial support actuators mounted at the mirror's back surface and 42 lateral actuators. The analysis includes static structural analysis under gravity load, support system sensitivity evaluation and simulation about correction ability of force actuators. The optimized deformation of the primary mirror meets the error budget. Though we find the honeycomb primary mirror is not so sensitive to variation of support forces, the mirror figure still can be compensated by adjusting the support forces.

Restoration of atmospheric turbulence-degraded image is needed to be solved as soon as possible in the field of astronomical space technology. This paper discusses the issue of regularization during the restoration process, a new restoration method of heavy turbulence-degrade image for space target based on regularization is proposed, in which the anisotropic, nonlinear Step-like and Gussian-like regularization models are adopted according to the properties of turbulence point spread function(PSF)and image. The nonlinear regularization functions are suggested to smooth in the process of estimating the PSF and recover the object image. In order to test the validity of the method, a series of restoration experiments are performed on the heavy turbulence-degraded images for space target and the experiment results show that the method is effective to restore the space object from their heavy turbulence-degraded images. Besides, the definition measures and relative definition measures show that the new method is better than the traditional method for restoration result.

The four-element infrared detecting system is a common used detecting system to detect a target from sky background. However, one of the main application limits of this system is the short detecting distance. Consequently, this paper presents an adaptive weak signal extraction algorithm, with which the weak distant target signal can be extracted, thus the detecting distance can be obviously lengthened.

In space attack and defense, on-orbital servicing, pose estimation of unknown (non-cooperative) spacecrafts is one of the most important conditions when taking the attack, defense and servicing measures. However, as for non-cooperative spacecrafts, the imaging characteristics of the features and the geometric constraints among the features are unknown, it is almost impossible to achieve target extraction, recognition, tracking, and pose solving automatically. To solve this technical problem, the paper proposes a method to determine the pose of non-cooperative spacecrafts based on collaboration of space-ground and rectangle feature. It employs a camera and rectangular features to achieve these operations above mentioned automatically. Experimental results indicate that both the position errors and the attitude errors satisfy the requirements of pose estimation during the tracking, approaching and flying round the non-cooperative spacecraft. The method provides a new solution for pose estimation of the non-cooperative target, and has potential significance for space-based attack and defense and on-orbital servicing.

The solar irradiance monitor (SIM), with the design accuracy of 5%, used to monitor the secular changes of the total solar irradiance on FY-3 satellite, takes the sun-scanning measurement method on-orbit. Compared to the sun-tracking measurement method, this method simplifies the structure and cuts the cost, but the measuring accuracy is affected by the sun-synchronous orbit, sunlight incidence angle and the installing angle of the SIM in the satellite. Through the ground calibration experiment, studies on the affection of different sunlight incidence angles to the measurement accuracy. First, by the satellite tool kit (STK) simulation software, simulates the orbital parameters of the sun-synchronous satellite, and calculates the Sun ascension and declination at any time. By the orbit coordinate transformation matrix gets the components of the Sun vectors to the axes of the satellite, and base on the components designs the field of view and the installing angles of the SIM. Then, designs and completes the calibration experiment to calibrate the affection of the incidence angles. Selecting 11 different angles between the sunlight and the satellite X-axis, measures the total solar irradiance by the SIM at each angle, and compares to the irradiances of the SIAR reference radiometers, and gets the coefficient curves of the three channels of the SIM. Finally, by the quadratic fitting, gets the correction equations on the incidence angles: 5 2 3 R1 5.71x10^-5α² - 2.453 10^-5 α² 1.0302, R₂ = 2.84×10^-5α²-1.965x10^-3α+1.0314 and R₃ =1.72x10^-5α²-4.184x10^-4α+0.9946. The equations will improve the on-orbit measurement accuracy of the solar irradiance, and are very important to the on-orbit data processing after the satellite launched.

Space payload is effected directly by space cryogenic environment, high radiation, etc. when working on orbit, especially large space payload a majority of which faces directly to formidable space nature condition. How to insure space payload working effectively on orbit is a key technology to space payload application technology. The papers starts from the optical system of a payload, to discuss the influence of optical system under the space cryogenic environment. Applying the law of optical imagery and the cryogenics thermodynamic method, and using Zernike polynomial coefficient to describe the changing of optical aberration on orbit and point spread function to evaluate the changing of performance of optical system. The papers optimizes the optical system of space payload by the means of temperature topology. From the data of final computation, by contrast to general optical system, for the same system, topological optic system can suit to more servers temperature condition that optical surface axial temperate grade is 5 to 10k, and can prove point spread function more than 0.2~0.3. so it can get the conclusion from analysis data that applying temperature topological optimization method can improve space payload optical quality by the mean of suiting to higher temperature grade, which more suit to space deep cryogenic environment. It gives model and data reference to extend space payload applying condition.

There is a limited cognition on human beings comprehend the universe. Aiming at the impending need of mars exploration in the near future, starting from the mars three-dimensional (3D) model, the mars texture which based on several reality pictures was drew and the Bump mapping technique was managed to enhance the realistic rendering. In order to improve the simulation fidelity, the composing of mars atmospheric was discussed and the reason caused atmospheric scattering was investigated, the scattering algorithm was studied and calculated as well. The reasons why "Red storm" that frequently appeared on mars were particularized, these factors inevitable brought on another celestial body appearance. To conquer this problem, two methods which depended on different position of view point (universe point and terrestrial point) were proposed: in previous way, the 3D model was divided into different meshes to simulate the storm effect and the formula algorithm that mesh could rotate with any axis was educed. From a certain extent the model guaranteed rendering result when looked at the mars (with "Red storm") in universe; in latter way, 3D mars terrain scene was build up according to the mars pictures downloaded on "Google Mars", particle system used to simulated the storm effect, then the Billboard technique was managed to finish the color emendation and rendering compensation. At the end, the star field simulation based on multiple texture blending was given. The result of experiment showed that these methods had not only given a substantial increase in fidelity, but also guaranteed real-time rendering. It can be widely used in simulation of space battlefield and exploration tasks.

High dynamic aircraft is a very attractive new generation vehicles, in which provides near space aviation with large flight envelope both speed and altitude, for example the hypersonic vehicles. The complex flight environments for high dynamic vehicles require high accuracy and stability navigation scheme. Since the conventional Strapdown Inertial Navigation System (SINS) and Global Position System (GPS) federal integrated scheme based on EKF (Extended Kalman Filter) is invalidation in GPS single blackout situation because of high speed flight, a new high precision and stability integrated navigation approach is presented in this paper, in which the SINS, GPS and Celestial Navigation System (CNS) is combined as a federal information fusion configuration based on nonlinear Unscented Kalman Filter (UKF) algorithm. Firstly, the new integrated system state error is modeled. According to this error model, the SINS system is used as the navigation solution mathematic platform. The SINS combine with GPS constitute one error estimation filter subsystem based on UKF to obtain local optimal estimation, and the SINS combine with CNS constitute another error estimation subsystem. A non-reset federated configuration filter based on partial information is proposed to fuse two local optimal estimations to get global optimal error estimation, and the global optimal estimation is used to correct the SINS navigation solution. The χ 2 fault detection method is used to detect the subsystem fault, and the fault subsystem is isolation through fault interval to protect system away from the divergence. The integrated system takes advantages of SINS, GPS and CNS to an immense improvement for high accuracy and reliably high dynamic navigation application. Simulation result shows that federated fusion of using GPS and CNS to revise SINS solution is reasonable and availably with good estimation performance, which are satisfied with the demands of high dynamic flight navigation. The UKF is superior than EKF based integrated scheme, in which has smaller estimation error and quickly convergence rate.

A stratospheric satellite, which is a new type of low-cost and low-energy-consumption spacecraft, can be controlled by a stratosail to orbit around the Earth's stratosphere from east to west at the height of 35 km. This paper researches on the visual simulation system of the stratospheric satellite's trajectory control. First, based on the more complete investigation of the characteristics of stratospheric environment and stratospheric winds, the trajectory control method of the stratospheric satellite is proposed, and then the components of the stratospheric satellite and their functions are given: a super-pressure helium balloon is used to balance the gravity, a stratosail to control the trajectory, and a 15km-long tether to connect the balloon and the stratosail to make them located in different wind strata. Second, the dynamic models of the balloon and stratosail are derived more compactly due to the appropriate options and definitions of various coordinate systems. After that, various simulations are carried out in scenarios of different wind conditions. Third, according to the dynamic models, the trajectory control scheme is proposed. In the end, the Creator and Vega Prime software platforms are applied to develop a visual simulation system for the trajectory control of the stratospheric satellite using the results of numerical simulations as input. The results of the visual simulation system show that the stratosail can be used to control the trajectory of stratospheric satellites precisely. Moreover, in the presence of wind disturbances the stratospheric satellite can still be controlled by the stratosail to fly from east to west along the predefined trajectory, namely, the control of the south-north direction is stable. Furthermore, through the visual simulation system, the trajectory control can be demonstrated visually, which means the control performance can be evaluated more intuitively.

The thin-walled baffle design of the space-based camera is an important job in the lightweight space camera research task for its stringent quality requirement and harsh mechanical environment especially for the thin-walled baffle of the carbon fiber design. In the paper, an especially thin-walled baffle of the carbon fiber design process was described and it is sound significant during the other thin-walled baffle design of the space camera. The designer obtained the design margin of the thin-walled baffle that structural stiffness and strength can tolerated belong to its development requirements through the appropriate use of the finite element analysis of the walled parameters influence sensitivity to its structural stiffness and strength. And the designer can determine the better optimization criterion of thin-walled baffle during the geometric parameter optimization process in such guiding principle. It sounds significant during the optimum design of the thin-walled baffle of the space camera. For structural stiffness and strength of the carbon fibers structure which can been designed, the effect of the optimization will be more remarkable though the optional design of the parameters chose. Combination of manufacture process and design requirements the paper completed the thin-walled baffle structure scheme selection and optimized the specific carbon fiber fabrication technology though the FEM optimization, and the processing cost and process cycle are retrenchment/saved effectively in the method. Meanwhile, the weight of the thin-walled baffle reduced significantly in meet the design requirements under the premise of the structure. The engineering prediction had been adopted, and the related result shows that the thin-walled baffle satisfied the space-based camera engineering practical needs very well, its quality reduced about 20%, the final assessment index of the thin-walled baffle were superior to the overall design requirements significantly. The design method is reasonable and efficient to the other thin-walled baffle that mass and work environment requirement is requirement harsh.

Spectral unmixing analysis for hyperspectral images aims at estimating the pure constituent materials (called endmembers) in each mixed pixel and their corresponding fractional abundances. In this article, we use a semi-supervised approach based on a large spectral database. It aims at finding the optimal subset of spectral signatures in a large spectral library that can best model each mixed pixel in the scene and computes the fractional abundance which every spectral signal corresponds to. We use l₂ - l₁ sparse regression technical which has the advantage of being convex. Then we adopt split Bregman iteration algorithm to solve the problem. It converges quickly and the value of regularization parameter could remain constant during iterations. Our experiments use simulated pure and mixed pixel hyperspectral images of Hubble Space Telescope. The endmembers selected in the solution are the real materials' spectrums in the simulated data and the approximations of their corresponding fractional abundances are close to the true situation. The results indicate the algorithm works well.

During satellite moving on orbit, effect of disturbance of satellite platform motion on optical system cannot be neglected. The influence on image quality of high-resolution optical system caused by satellite platform motion was analyzed in this paper. First, as linear, sinusoidal and random motion are three kinds of fundamental motion mode of satellite platform, the effects of the disturbance of linear, sinusoidal and random motion on Modulation Transfer Function (MTF) of optical system were simulated respectively. Second, based on the simulation results, conclusion that the Modulation Transfer Function (MTF) was degraded in various degrees under different modes of motion disturbance was obtained. To improve the axis stability of optical system for a high-resolution image, a coupler was researched and installed between the satellite platform and the optical imaging system to attenuate the disturbance from the satellite platform, and adaptive optics correction was adopted to correct the residual disturbance effect in real-time. By combining the coupler and adaptive optics correction, the high-resolution imaging was guaranteed effectively.

In this paper we investigate the attitude measurement based on X-ray pulsar scanner, the detection efficiency of X-ray pulsar scanner is described by the transfer function. We present the attitude measurement models of X-ray pulsar scanner, which is fit by Genetic Algorithms. The attitude angles of the spacecraft are gained by numerical simulation techniques. Firstly, the coordinate systems and the conversion matrices of the attitude measurement based on X-ray pulsars scanner are presented. The structure of the X-ray pulsar scanner is designed. The differences between X-ray pulsar scanner and the classic scanner are analyzed, and the advantages of X-ray pulsar scanner are discussed. The collimation process of X-ray pulsar collimator is analyzed, the transfer function of collimator is given. The detection efficiency of X-ray pulsar scanner is described accurately by the model of transfer function. The geometric projection angle of the pulsar in the instrument coordinate system is defined which are used to describe function of collimator. Secondly, by using the transfer function of collimator and spacecraft attitude dynamic equations, the mathematical model between the geometric projection angle and the spacecraft attitude angle is established. The described equation of X-ray photon curve is deduced by using the transfer function and the mathematical model. The photon curve recorded by scanner is fitted by the equation. The attitude measurement model based on X-ray pulsar scanner is obtained. This model is discrete mathematical model of optimization. The Genetic Algorithms is adapted for the discrete mathematical model of optimization. The model is optimized by Genetic Algorithms, and the unit vectors of pulsars in the instrument coordinate system are obtained. The spacecraft attitude angles are calculated finally by the double-vector method. Finally, the above models are verified by the numerical simulation. The feasibility and effectiveness of the attitude measurement based on X-ray pulsar scanner are shown by the simulation results. The X-ray pulsar signal is strong, and it is apt to be detected by small devices. Therefore, the spacecraft payload is reduced. The natural X-ray signal is not susceptible to man-made disturbance. The safety and autonomy of the spacecraft are enhanced. This paper provides a new technique for spacecraft attitude measurement.

The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20μrad and burden heavy load to the best of one's abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

Deep space exploration is one of the hot techniques currently. The small and dim point target detection is one of the key technologies for space surveillance. In order to detect the small and dim point target without background compensation, we proposed a new method to realize the target detection in the feature space which we special designed. This method makes the centroid location to denote each of all the stars and targets separately, when the reference stars are chosen, the images could be mapping in the feature space which gets from the changing distance from all stars and potential targets to the reference stars, then the stars and potential targets can be divided by comparability measurement function with different motion characteristics, finally by trajectory conjunction the target detection be realized. The method we present here can be widely used in the visible light space surveillance system and infrared systems, and employed not only ground based surveillance system but also space based surveillance systems, which can also play an important role in space debris surveillance. The experimental result shown that the algorithm can fully take into account the characteristics of the fixed star, dim point moving target and noise, and can be effective to detect the moving dim and small in moving background with low SNR.

Wireless sensor networks (WSNs) have emerged as an important method for planetary surface exploration. To investigate the optimized wireless technology for WSNs, we summarized the key requirements of WSNs and justified ultra wideband (UWB) technology by comparing with other competitive wireless technologies. We also analyzed network topologies as well as physical and MAC layer designs of IEEE 802.15.4a standard, which adopted impulse radio UWB (IR-UWB) technology. Our analysis showed that IR-UWB-based 802.15.4a standard could enable robust communication, precise ranging, and heterogeneous networking for WSNs applications. The result of our present work implies that UWB-based WSNs can be applied to future planetary surface exploration.

The CCD Stereo Camera is a principal science payload on board the Chang'E-1 (CE-1) satellite, developed and launched by China for the first Lunar Exploration Program. The principal task of the camera is to take image of the lunar surface in the visible band and obtains three-dimensional lunar terrain. The CCD Stereo Camera is designed based on threelinear array photogrammetric theories. The focal plane of the camera is comprised of a frame transfer CCD with size of 1024x1024 pixels. There are only three lines to be used to form a three-linear array, and the other lines are not used. The timing and control circuits of the camera are designed based on FPGA. An Actel's anti-fuse based FPGA, A1020B, is available, but the speed and logical resources of the device both are limited. This paper describes the design requirements, considerations and trade-off subject to the constraints. Especially, A novel logic circuit is introduced to generate the pulses with width of about 10ns~20ns with constraint of 8MHz external clock, which is used to design correlated double sampling (CDS) control signals and CCD reset signal. Finally, the result of flying verifications on-board of the timing and control circuits are also described.

Among kinds of ways to improve the early-warning of a country, identifying the space object material in a better and faster way is an important and effective method. The hyperspectral image, which is a 3-D data cube and contains the spatial and spectral information of the interest objects, will play a more important role in identifying the space object material. However, the low spatial resolution of the hyperspectral remote sensing instrument makes the single pixel spectrum often mixed up several different materials' spectra, which is called mixed pixel. So it is a considerable question to decompose the mixed pixels into spectra of pure materials (called endmembers) and get their corresponding fractions (called abundances). Since a hyperspectral image can be seen as a 3-D tensor, nonnegative tensor factorization (NTF) algorithm based on tensor analysis can be introduced into the field of hyperspectral unmixing. However, random initialization, a classical way to initialize the NTF algorithm, causes a slow rate of convergence, which can be improved through other methods to initialize this algorithm. This paper selects the vertex component analysis (VCA) algorithm to initialize the NTF algorithm. In this way, a faster and better result is obtained, and furthermore, four simulated hyperspectral images dataset of 3-D model of Hubble Space Telescope with different spatial resolutions are processed by the improved algorithm in this paper, and good results are obtained.

Because of the presence of cloud, the quality and application of data obtained in visible light and infrared bands are affected when remote sensing images are generated. This paper proposes an automatic selection method with the best cut-off frequency to remove the effect of thin cloud in remote sensing images quickly and efficiently. Based on the homomorphic filtering method of the simple thin cloud imaging model and the self-similarity of the spatial form of thin cloud and haze, this paper uses the multi-fractal technology and the filtering technology of the S-A model (power spectrum-area model) to determine the filtering radius automatically. The experiments of removing thin cloud and haze for remote sensing images show that the filtering technology of the S-A model is related to the spatial form of image contents directly. Compared with usual filtering technologies which choose frequency as radius, this method can not only achieve rapid and automatic filtering of remote sensing images, but also remove the effect of thin cloud in remote sensing images effectively.

Aperture diffraction ageometric aberrations asurface scatter and other errors -setting errors Aenvironmental errors- are several influencing factors on imaging performance of optical system. Especially for short wavelength imaging systems, Surface scattering effects is one of mainly influencing factors which is severely degraded imaging performance. It is necessary that study surface scattering phenomenon to development of short wavelength optics. In this paper, aim at space solar telescope, effect of surface scattering on imaging performance of the grazing incidence systems is evaluated. By combining these scattered light distributions of super-smooth surfaces measured by a soft X-ray reflectometer, and surface scattering numerical model of grazing incidence imaging system, PSF and encircled energy of optical system of space solar telescope are computed. We can conclude that surface scattering severely degrade imaging performance of grazing incidence systems through analysis and computation.a

At present, according to various optical and signal processing methods, there are mainly three detection modes in laser radar system: direct detection, heterodyne detection and homodyne detection. A homodyne laser radar system made up of a narrow line-width laser, an amplitude modulator and balanced detector is introduced here. Both transmitted and local oscillator (LO) signals are amplitude modulated by the same chirp signal, and the de-chirping process is completed in the optical domain. When we do signal processing on range and Doppler frequency, we use chirp-z method besides normal Fourier Transform. In this way, we get the experiment data more accurately. The experiment data indicates that the range and velocity precision reaches cm and mm/s dimension which are basically conforming to the theoretical precision.

It is important to retrieve aerosol optical properties over coastal region not only for study of oceanic productivity but also for study of climate because coastal region is highly influenced by neighboring aerosol source regions. The present operational Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol retrieval algorithm works reasonably well over clear ocean areas but fails to give any results over brighter coastal waters. This is because: the turbid waters are not dark for the two aerosol retrieval channels centered near 0.553ìm, 0.646ìm. We have developed an aerosol retrieval algorithm for remote sensing of aerosol properties over turbid coastal water. In this algorithm, channels centered near 0.86,1.24,1.64 and 2.13ìm are used. If necessary, the reflectance of 0.86ìm will be corrected. The proposed algorithm is applicable for MODIS data observed over turbid coastal water in the southeast of China. The retrieval results agree quite well with the measurements obtained with sun photometers, and it can be easily used in the present operational aerosol retrieval algorithm. As a result, many valuable aerosol data can be obtained.

In the spectral imaging process of interference imaging spectrometer, the impact caused by motion errors of satellite platform is not only the degradation of spatial resolution but also the aliasing and distortion of spectral information. The degradation function is modeled though analyzing the degradation mechanism of spectral imaging. And a correction algorithm based on interference sequences is proposed to solve this problem. In this algorithm, the interference sequences is regarded as an integer and the degradation model is thought to be three-dimensional, including two spatial dimensions and one spectral dimension. And the degraded interference sequences are the convolution of the original sequences and the degradation function. According to the vibration data measured by POS on the satellite, the degradation function can be obtained. Then the corrected interference sequences can be got by de-convolution of the degraded sequences and the degradation function though Hopfield neural network based on continuous variation of states. And by reconstructing of the corrected sequences, the corrected images and spectrums can be got finally. The simulated results show that this algorithm can correct the degradation of images and the distortion of spectrums caused by motion errors of satellite's attitudes effectively.

A radiation-hardened Bipolar NPN differential pair is developed and fabricated in the 4μm 20V process. The total ionizing dose response of the unhardened NPN and hardened NPN are compared. The experimental results indicate that after the radiation total dose of 100krad (Si) the current gain of the unhardened NPN is reduced by about 60%~65%. Under the same radiation condition, the current gain of the hardened NPN is greater 15%~20% than the unhardened NPN. Subsequently, the input offset voltage and current of unhardened and hardened differential pairs are measured before and after the radiation total dose of 100krad (Si).The results show that the standard deviations of hardened differential pairs are much smaller. Theory analysis and experiment shows that the radiation hardness approaches are reasonable and efficient.

Pulsar navigation is a promising new technique for space exploration because of its autonomous and deep space capability. Since the baseline of pulsar navigation approach is to observe the X rays (0.2~20keV) emitted from pulsars, a compact high temporal resolution X-ray detector is needed. In this paper an micro-channel plate(MCP) photon counting detector sensitive to X-rays is proposed. The detection system consists of a CsI photocathode, a 50mm diameter micro-channel plate (MCP) stack, a collection anode, a preamplifier, a constant fraction discriminator(CFD) and data acquisition(DAQ). The incident X-rays photons are absorbed by CsI and converted to photoelectrons, the electrons are multiplied by MCP and collected by the anode. Anode output signal is a fast pulse which need to be amplified by preamplifier and then fed to CFD circuit and DAQ for a precise timing. The total temporal resolution (ΔT) of the entire detection system could be determined by ▵tD, the intrinsic temporal resolution of cathode-MCP-anode, and ▵E the resolution of electronic system including preamplifier and CFD. The resolution of the detection system is tested to be 18.4ns in experiment.

High sensitivity and SNR are requested in lunar astronomical observation in order to get dark and feeble objects. Scientific CCD Cameras used in lunar astronomical observation usually have following characteristics: high quantum efficiency, wide spectral response, good photometric linearity and wide dynamic range. However, extremely low readout noise is usually a key indicator of the camera. A CCD camera, based on E2V's back-illuminated ultraviolet-enhanced scientific grade AIMO image sensor, has been designed for lunar astronomical observation. Four major kinds of electrical optimal design are presented in order to reduce the readout noise of the camera. The experiment result shows that: in the 200K pix/s of the pixel clock, the camera system gain is 1.83e-/ADU, and the readout noise is less than 6e-.

Thermoelectric cooler (TEC) is a kind of solid hot pump performed with Peltier effect. And it is small, light and noiseless. The cooling quantity is proportional to the TEC working current when the temperature difference between the hot side and the cold side keeps stable. The heating quantity and cooling quantity can be controlled by changing the value and direction of current of two sides of TEC. So, thermoelectric cooling technology is the best way to cool CCD device. The E2V's scientific image sensor CCD47-20 integrates TEC and CCD together. This package makes easier of electrical design. Software and hardware system of TEC controller are designed with CCD47-20 which is packaged with integral solid-state Peltier cooler. For hardware system, 80C51 MCU is used as CPU, 8-bit ADC and 8-bit DAC compose of closed-loop controlled system. Controlled quantity can be computed by sampling the temperature from thermistor in CCD. TEC is drove by MOSFET which consists of constant current driving circuit. For software system, advanced controlled precision and convergence speed of TEC system can be gotten by using PID controlled algorithm and tuning proportional, integral and differential coefficient. The result shows: if the heat emission of the hot side of TEC is good enough to keep the temperature stable, and when the sampling frequency is 2 seconds, temperature controlled velocity is 5°C/min. And temperature difference can reach -40°C controlled precision can achieve 0.3°C. When the hot side temperature is stable at °C, CCD temperature can reach -°C, and thermal noise of CCD is less than 1e-/pix/s. The controlled system restricts the dark-current noise of CCD and increases SNR of the camera system.

In order to optically vary the effect focal length of optical zoom system , adds two or more active optics which could supply variable the focal length, and create an imaging system with variable optical magnification that has no macroscopic moving parts. Based on this design concept, and connected with off-axis three-mirror reflective optical system design, we have presented preliminary modeling showing that active optical elements can be used as to create a zoom system that the effective focal length from 1000 mm to 3000 mm in ZEMAX, the FOV(Field of view) is 16°×2° -6.87°×0.86°, and the F/# is 5-15, the whole system is composed of 3 reflective mirrors(DM, Deformable Mirrors). In order to zoom system, the F/# and three reflective mirror's radius, were variable. The MTF more than 0.45 at the spatial frequency of 42lp/mm and approaches the diffraction limit, the maximum RMS spot diameter less than detector's size. The results show that the imaging quality can satisfy the requirement of the system.

The carbon-carbon composite (CCC) was applied in order to design and fabricate much more predominant lunar optical telescope (LOT). The fabricating technics of CCC and machining technics of load-carrying cylinder assembly are introduced. The density of CCC is 1.73g/cm³, and the coefficient of thermal expansion is 0.5×10^-6/°C. The thermal adaptability of LOT was analyzed, the operating temperature of LOT will be improved to -20°C~+40°C that the carbon-carbon cylinder is used. Finite element analysis of LOT with CCC cylinder was performed, and the results show that the first frequency of LOT is 185Hz. The machining and assembling of LOT have been performed. The vibration testing has been accomplished and the testing results are consistent with finite element analysis. The testing results show that load-carrying cylinder of CCC can stand the mechanical proof. All analysis and testing indicate that CCC can be competent for LOT.

Cherenkov radiation is used to study the production of particles during collisions, cosmic rays detections and distinguishing between different types of neutrinos and electrons. The optical properties of water are very important to the research of Cherenkov Effect. Lambert-beer law is a method to study the attenuation of light through medium. In this paper, optical properties of water are investigated by use of a water attenuation performance test system. The system is composed of the light-emitting diode (LED) light source and the photon receiver models. The LED light source model provides a pulse light signal which frequency is 1 kHz and width is 100ns. In photon receiver model, a high sensitivity photomultiplier tube (PMT) is used to detect the photons across the water. Because the output voltage amplitude of PMT is weak which is from 80mv to 120mV, a low noise pre-amplifier is used to improve the detector precise. An effective detector maximum time window of PMT is 100ns for a long lifetime, so a peak holder circuit is used to hold the maximum peak amplitude of PMT for the induced photons signal before the digitalization. In order to reduce the noise of peak holder, a multi-pulse integration is used before the sampling of analog to digital converter. At last, the detector of photons from the light source to the PMT across the water is synchronized to the pulse width of the LED. In order to calculate the attenuation coefficient and attenuation length of water precisely, the attenuation properties of air-to-water boundary is considered in the calculation.

Deep space life exploration nowadays mainly focuses on whether environments on other planets are suitable for the existence of life. This has not hit the key point. As life depending on its specified conditions, it is of great necessity and importance to conduct exploration in the life's original environment. An idea was put forward in this paper to detect specific life forms in the original environment if they exist. This idea, based on fluorescence, included light source unit and detection unit. The former was optical fiber coupled LED and lens; the latter was charge coupled device (CCD) and other lens. Light from LED was collected and transferred by optical fiber, then purified by a filter in order to obtain specific wavelength light, which could excite corresponding organic biological molecules. These molecules emitted light of other wavelength, usually referred to as fluorescence, the moment they were illuminated by excitation light. The fluorescence was also purified by another filter. Then lens was used to collect the light. As to detection device, CCD would give fluorescence image. Theoretical analysis demonstrated that the system could meet the task's requirements. During test in laboratory, this system performed well, too. CCD could output desired signals. This provided strong support that the idea present in the paper is feasible and is of practical significance.

Scanning lidar imaging system using a linear detector array is constituted by both sides into 45° angle of mutual mirror composition. The construction of equivalent optical systems is greatly simplified in the imaging derivation process with intuitive method and analytic geometry. The optical imaging formulas are accurately derived for all the spots of the image. Based on the imaging requirements of the Lunar and Mars exploration technology, numerical simulations and error analysis were performed in the paper. It is shown that the maximum distortion ratio of the central spots pillow-shape distortion image is 3.41% in horizontal direction and the excursion of the edge spots by laser pulse at certain divergence angle is 0.194m, 0.096m in horizontal direction and vertical direction, respectively. The work of this paper can provide the theory basis of the lidar imaging signal processing on-line or off-line used in the deep space exploration projects.

Attitude control and determination along with the fix and navigation of the spacecraft is the fundamental functional elements in the space scientific research tasks. Nadir vector is usually applied in the attitude determination of spacecraft relative to the Earth, and it is also commonly used as a reference vector in autonomous navigation especially in the satellites' preliminary coarse orbit determination. In the paper, we begin with the shape of the Earth as seen from the space, which is defined by the Earth horizon as seen from the position of the observer. The geometric model of the nadir vector pointing from the spacecraft to the Earth center is established basing on three-dimension earth spheroid model; the effect of Earth flattening on the attitude determination and positioning is discussed, the flattening and irregularity of the Earth ultraviolet layer model are the major error sources resulting in poor accuracy of attitude determination and fix. An error modification method is presented to compensate for the Earth flattening error. Several crucial techniques in determining earth center and nadir vector basing on CCD sensor are stressed in the paper. Noise elimination and image processing means are introduced to restraint the influences of harmful signals in the image acquisitions; edge detection is one of the most important aspects in the process of determining the Earth center, Randomed Hough Transformation method and least square method are effective way to check the edge of earth horizon profile.

This paper presents a compact frequency-independent equivalent-circuit model for mmW characteristics of lithium niobate (LiNbO₃) optical modulator, taking the skin effect, and substrate effect into consideration. Equivalent-circuit model with only ideal lumped elements represents the broadband electrical response of LiNbO₃ modulator. A 4-long ladder model is used to model the skin effect. Coupling capacitor is used to simulate the substrate coupling from the CPW to the buffer and LiNbO₃ substrate. Lumped-element circuit model was cascaded to model the distributive skin effect, transmission attenuation, and substrate effect. The equivalent-circuit models are fully SPICE compatible and can be incorporated directly into common circuit simulators and microwave design tools.

In the World Space Observatory-Ultraviolet (WSO-UV) mission, the Long Slit Spectrograph (LSS) instrument will provide low resolution spectra in the range 102-320nm. Both the NUV (160-320nm) and the FUV (102-170nm) channels of LSS use microchannel plates (MCP) working in photon-counting modes as detectors. In this paper, the progress and parameters of NUV and FUV photon-counting imaging detectors were described. For the NUV detector, we developed the detector based on a sealed MCP-image intensifier which comprises input window, photocathode, MCP stack, Ge-layer and its ceramic substrate. To maximize the quantum efficiency, we adopted a Caesium Telluride (C_s2Te) photocathode, which was deposited on input window and mounted close to the MCP. For the FUV detector, because of the lower cut-off wavelength, there are no suitable window materials in this band and the open-faced design should be used to meet the requirements of the detection. Therefore, a Caesium Iodide (CsI) photocathode deposited on the input surface of the MCP was used to optimize detector efficiency. By using an existing wedge and strip anode (WSA), the imaging performance of the NUV and FUV detectors was tested respectively. Experimental results show that the quantum efficiency of Cs₂Te is 12.1% (at 230nm), the spatial resolution of NUV and FUV detectors is better than 110μm, the dark count rate of NUV and FUV detectors is about 10.5- and 2.3-counts/s*cm2 respectively.

The camera's motion of detecting and tracking GEOs in spaced-based or ground-based observation platform is very complicated because of the controls of camera's motion for accomplishing the tracking and the motion of platform itself. The controls include: the converts between spontaneous encounter mode and vertical scan mode, detecting and tracking the GEOs with different velocities, etc. The sudden conversion between different modes would make a obvious imaging difference between the two neighbor star-images: stellar shape turn long strip from point, the background's motion is not also uniform linear or constant angular rotation. The imaging difference and irregularity of background's motion enhance the difficulties of star images registration. But the step of registration is necessary in processing of detecting and tracking GEOs based on images sequence. At present almost registration algorithms are designed for some ideal situations or some special conditions needed, thus less of robust to overwhelm the imaging difference and irregularity of background's motion, so most of these are not suitable for automatically detecting and tracking under complicated circumstances in engineering. Another point is that these algorithms are constructed only in image processing level and not consider from astronomy angle. In this paper, an algorithm identifying stars for navigation in astronomy fields is introduced to images registration. For accomplishing to convert camera coordinate to right ascension and declination of sun, there are some parameters should be got in advance, including CCD camera's focal length, field angle and the current camera's axis pointing for building a proper star catalogue. Fortunately to an observation platform, these parameters are known.

In this paper, the bistatic LRCS of Teflon spheres of different size is measured by laser scattering automatic measurement system in laboratory and bistatic LRCS measurement system outdoor respectively, and the bistatic LRCS of standard Lambert spheres of the same size is calculated. The experimental results show that Teflon sphere has obvious coherent scattering when the bistatic angle is smaller than 10°. The experimental results coincide with the theoretical calculation when the bistatic angle is bigger than 10°. Scaling relations of the bistatic LRCS is also studied in experiment, the relative error between the experimental results of scaling relations and the theoretical calculation results of scaling relations of the same size Lambert sphere is smaller than 10 percent, which satisfies the requirements of Engineering. It is demonstrated that outdoor measurement method has valuable usage in engineering practice to measure the bistatic LRCS of large object.

Methods for pose estimation of flying objects are introduced. Among them is the model-based optical method. We focus on the feature description aspect in model-based method. Feature descriptors of chain codes, moments, Fourier descriptors are used for 2D silhouette or region description. Common issues and techniques, particularly representation and normalization, of such three kinds of descriptors in the application of model-based pose estimation are analyzed. We build a Matlab pose estimation framework to compare pose estimation procedures using different feature descriptors. A missile model of MilkShape 3D file format is created as the simulation object. Experiments concerning with the abilities of descriptors are proceeded to show the difference of these descriptors.

Along with the continuous development of the research in the space exploration field, the precision rotation control system is widely utilized in a lot of payloads of the satellites. It is stepping motor cooperating with reduction gear wheel to accomplish the precision rotation in some pointing platforms of the camera used in the satellite. By contrast with that, the approach of this paper could precisely control the rotation angle of the stepping motor without using reduction gear wheel. Therefore, the size and the height of the instrument would be reduced base on simplifying the structural design. Moreover, it reduces the cost to some extent. In this paper, it is adopted that the digital signal processor (DSP) controller and bipolar constant current motor drive circuit UC3717 to make a high performance, high subdivision, miniature control system come true, which is used to drive two-phase hybrid stepping motor. The methods are applied by the driver system that sine cosine micro stepping and constant current chopper drive with a fixed chopper period. The driver system also supplies the functions that involve subdivision selection, clockwise rotation or counter clockwise rotation control, and over current or over voltage or under voltage or overload protection, and so on. The description in this paper also includes the total schematic design, the approach to get current table in different subdivision levels, the current control method in hybrid stepping motor, the way to reduce electro- magnetic interference (EMI) of the hybrid stepping motor. And the total schematic design contains the DSP controller, the communication interface of the driver system, the design of power driving circuit, the interface circuit between the electrical sources, the constant current chopper drive circuit for the two-phase hybrid stepping motor. At last, it is verified by some experimental investigations that the control system not only has miniature size, simplified system design, improved high frequency torque frequency characteristic and low frequency stability, but also has enhanced adaptability and self-protection capability, improved accuracy of position control and reliability of the driver. And the driver system is capable of dividing a full step into 256 micro steps. because it is 1.8°that the angle of the full step of the two-phase hybrid stepping motor in the full step mode, therefore, it results in 51,200 steps per revolution (0.007º/step). So it could fulfill the demand of the precision rotation control system used in some payloads of the satellites.

This paper According to the local approximate solution and finite series expression to the beam coefficients presented by Gouesbet and otherwise, we put forword a comprehensive recursive continued fraction algorithm and modify the defect of the existing algorithm, three key functions in scattering light intensity are recursively operated respectively, Mie scattering coefficient is obtained by using backward-recursive continued fraction algorithm, the highest recursive term is created automatically by computer and data fitting, the operation of angle function is carried out with Time forward-recurrence method, the beam coefficients equal to the local approximate solution and finite series expression, the relationship between scattering light intensity, gridling radius, particle size parameterer, relative refractive index and scattering angle is simulated based on MATLAB program and numerical calculation.

Abstract Of all the hyperspectral imaging system using the optical filtering elements available,. AOTF(Acousto-optic tunable filters) is best to choose a filtering optical element that has high-speed spectral selectivity with high resolution, it can greatly reduces the amount of data collection and processing. In this paper , First, the work principle of AOTF was introduced, then described the AOTF imaging system, it covers the spectral band from 400nm to 900nm with a spectral resolution of near 2nm at 400nm and 10nm at 900nm. The device can provide about 2.2° view field angle and 10mm aperture, which included TeO₂ crystal, image optical system, a charged coupled device(CCD)camera, rf electronics and control and processing software. Finally the paper presented the results of laboratory image testing.

Crater detection and classification are critical elements for planetary mission preparations and landing site selection. This paper presents a methodology for the automated detection and matching of craters on images of planetary surface such as Moon, Mars and asteroids. For craters usually are bowl shaped depression, craters can be figured as circles or circular arc during landing phase. Based on the hypothesis that detected crater edges is related to craters in a template by translation, rotation and scaling, the proposed matching method use circles to fitting craters edge, and align circular arc edges from the image of the target body with circular features contained in a model. The approach includes edge detection, edge grouping, reference point detection and geometric circle model matching. Finally we simulate planetary surface to test the reasonableness and effectiveness of the proposed method.

In this paper, a useful lossless compression method of hyperspectral remote sensing images is presented, which combines three-dimension adaptive predictor (3-DAP) and JPEG-LS algorithm. By using LDPC codes as the error-correction scheme, a compressed image transmission system with high spectral efficiency is proposed over Rayleigh fading channel. Linear programming (LP) decoding of LDPC codes is widely concerned for its maximum likelihood features and the maximum likelihood (ML) decoding for LDPC codes can be relaxed to an LP optimization problem. Therefore, the paper focus on an efficient algorithm called infeasible primal-dual interior-point (IPDIP) algorithm for solving LP problem with predictor-corrector technique. This technique decreases the amount of infeasible points and keeps them closing to the central path. Simulation results show that the lossless compression algorithm can reconstruct the hyperspectral image completely with higher compression ratio than JPEG-LS's. Moreover, the image transmission system achieves good bit error rate (BER) performance and good global convergence properties with less iteration number and time.

An important research interest on space optics is the ultra-light space telescope technology which is compatible with microsatellite platform. To realize lightweight telescope, one way is to develop deployable telescopes. They not only maintain the capabilities of traditional non-deployable telescopes but also have compacter launch volume and lighter weight and lower cost. We investigate the telescope with accurate deployable structure based on tape springs. Before launch, the secondary mirror support structure with tape springs is folded, and when the satellite is on orbit, the secondary mirror is deployed with the elastic strain energy of folded tape springs. There are mainly three parts in the paper. Firstly, the telescope optics was presented. A Ritchey-Chretien (RC) type optical system with 300mm aperture was designed. The influence of the secondary mirror misalignment on the optical performance was analyzed. Secondly, the deployable telescope structure with tape springs was designed for the RC system. The finite element method (FEM) was used to analysis the dynamics of the unfolded telescope structure. Finally, the deployment precision metering system was discussed.

Methane (CH4) is a potent greenhouse gas and it's second in importance only to CO2 with relative global warming ability 23 times that of CO2 over a time horizon of 100 years. It has a much shorter atmospheric lifetime, about 12 years and released to the atmosphere by biological processes occurring in anaerobic environments. Interannual variations of the atmosphere CH4 have been studied utilising Atmosphere Infrared Sounder (AIRS), onboard NASA's Aqua Satellite, and data of CH4 emission in Peninsular Malaysia during the period 2003 - 2009. AIRS is one of several instruments onboard the Earth Observing System (EOS) launched on May 4, 2002. The analysis of CH4 above five dispersed stations in study area shows the seasonal variation in the CH4 fluctuated considerably between wet and dry period and high CH4 growth rates observed at the end of each year were attributed to the reduced hydroxyl (OH) sink and the increased emissions from wetlands and biomass burning. The CH4 value in the north regions, up of the latitude 4º, higher than its value in the rest of regions throughout the year. The CH4 values in dry season higher than wet season. The monthly CH4 maps were generated, to study CH4 distribution over peninsular Malaysia for 2009, using Kriging Interpolation technique. The AIRS data and the Satellite measurements are able to measure the increase of the atmosphere CH4 concentrations over different regions.

Maneuvering spacecraft, a state-of-art platform, is paid more and more attention on for the upcoming space exploring. The integration of CNS (Celestial Navigation System) and INS (Inertial Navigation System) is the promising autonomous navigation candidate for maneuvering spacecraft. However, the star image of CNS may be heavily degraded by the large attitude variation in the spacecraft maneuvering. The effect of the attitude variation on the star image is twofold: the enlarged areas and the reduced pixel gray value of the star image. Both of them will degrade the extracting accuracy of the star image center directly. Therefore, the feasibility of CNS for the maneuvering spacecraft mainly depends on the mitigation of the effect of the attitude variation on the star image. In this paper, the star image motion is modeled when the spacecraft attitude is maneuvering firstly. The pixel gray value of the star image is also formulated in the span of exposure according to the camera exposure model. Then, the motion compensation values for the star image are deduced with the INS angular velocity in the rolling, yaw, and pitch axes respectively. The compensated star image's center is extracted accurately in the following. Finally, the compensation method is validated by simulations. The simulation results prove that the star image center extraction is as accurate as 0.1 pixel with the aiding of a tactical INS even though the spacecraft angular velocity is as large as 30º/s.

Semiconductor saturable absorber mirror (SESAM) is widely used in both fiber and solid state lasers for passively mode-locking in which two lenses are usually used to realize the coupling system between an SESAM and a fiber or solid material. The method of optical propagation matrix is used to calculate the changes of the diameter of a Gaussian beam in such a coupling system, the results show that the beam diameter could increase or decrease several times by properly choose the focal lengths of the two lenses and the space between them. As a result, the change of the average mode area inside the SESAM is fulfilled. This method has a great significance in reality and greatly increased the flexibility of a given SESAM with fixed saturation fluence in different type of lasers and laser configurations.

With the development of aerospace remote sensing technology, the ground resolution of remote sensing camera enhances continuously. Since there is relative motion between camera and ground target when taking pictures, the target image recorded in recording media is moved and blurred. In order to enhance the imaging quality and resolution of the camera, the image motion had to be compensated. In order to abate the effect of image motion to image quality of space camera and improve the resolution of the camera, the compensation method of image motion to space camera is researched. First, the reason of producing drift angle and adjustment principle are analyzed in this paper. This paper introduce the composition and transmission principle of image motion compensation mechanism. Second, the system adopts 80C31 as controller of drift angle, and adopts stepping motor for actuators, and adopts absolute photoelectric encoder as the drift Angle measuring element. Then the control mathematical model of the image motion compensation mechanism are deduced, and it achieve the closed-loop control of the drift angle position. At the last, this paper analyses the transmission precision of the mechanism. Through the experiment, we measured the actual precision of the image motion compensation mechanism, and compared with the theoretical analysis.There are two major contributions in this paper. First, the traditional image motion compensation mechanism is big volume and quality heavy. This has not fit for the development trend of space camera miniaturization and lightweight. But if reduce the volume and quality of mechanism, it will bring adverse effects for the precision and stiffness of mechanism. For this problem, This paper designed a image motion compensation that have some advantages such as small size, light weight at the same time, high precision, stiffness and so on. This image motion compensation can be applicable to the small optics cameras with high resolution. Second, the traditional mechanism control need to corrected, fitting and iterative for the control formula of mechanism. Only in this way, we can get the optimal control mathematical model. This paper has high precision of the control formula derived. It can achieve the high precision control without fitting, It also simplify the difficulty of control mathematical model establishment.This paper designed the range of adjusting of image motion compensation mechanism between -5°~ +5°. Based on choosing-5°, -4°, -3°, -2°, -1°, 0°, +1°, +2, +3°, +4°, +4° as the expectation value of the imaginary drift angle, we get ten groups of the fact data in adjusting drift angle measured. The test results show that the precision of the drift angle control system can be achieved in 1. It can meet the system requirements that the precision of the control system is less than 3 ', and it can achieve the high-precision image motion compensation.

Bipod flexures are used in many high-precision space mirror mount applications. The flexures are used to provide moment isolation for the mirror to minimize surface figure distortion resulting from mount assembly error or distortion of the mount temperature-change-induced. In this paper, we developed a bipod flexure for the Zerodur primary mirror with diameter 520 mm and thickness 70 mm. The characteristic of the bipod flexure is the two-strip flexure on the top and bottom of each leg. By those, the bending stress in mirror resulting from the mount assembly is remarkably reduced. Thanking to a semi-open structure with small mouth and big stomach in the back and a six parts symmetrical honeycomb structure for the primary mirror, using the FEA (Finite Element Analysis) method we analyze that how the axial and circumferential locations of the three bipod flexures impact mirror surface figure and gain the better result after optimization. In the design of the detail bipod flexures, thickness of the blade is analyzed and compared; also we achieve an optimization design. The two results demonstrate that the bipod flexures could keep the precision of the mirror surface figure under the load of external force and thermal constraints and meanwhile they could keep stability of structure.

Anisoplanatism refers to the fact that the turbulence-induced wavefront distortions for propagation paths from the observed object with even slightly different propagation directions can be considerably different. A numerical simulation method of anisoplanatic imaging through volume atmospheric turbulence has been developed in this paper. The propagation of optical rays through volume turbulence is considered as a process of successive scattering of the light wave by a set of phase screens. We give the calculation method of the optimal configuration for multiple phase screens, and t give the flow chart of the whole simulation process of anisoplantic imaging. Then, the anisoplanatic degradation as a function of the separated angle as seen from the receiving aperture of telescope for various numbers of phase screens and different aperture diameters is analyzed. The analyses of the simulation data show that three phase screens is adequate to the representation of the effect of volume turbulence. The simulation method presented here is applicable to a wide range of parameters of telescope imaging system and atmospheric turbulence.

Drift angle is a transverse intersection angle of vector of image motion of the space camera. Adjusting the angle could reduce the influence on image quality. Ultrasonic motor (USM) is a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. They have many advantages in comparison with conventional electromagnetic motors. In this paper, some improvement was designed for control system of drift adjusting mechanism. Based on ultrasonic motor T-60 was designed the drift adjusting system, which is composed of the drift adjusting mechanical frame, the ultrasonic motor, the driver of Ultrasonic Motor, the photoelectric encoder and the drift adjusting controller. The TMS320F28335 DSP was adopted as the calculation and control processor, photoelectric encoder was used as sensor of position closed loop system and the voltage driving circuit designed as generator of ultrasonic wave. It was built the mathematic model of drive circuit of the ultrasonic motor T-60 using matlab modules. In order to verify the validity of the drift adjusting system, was introduced the source of the disturbance, and made simulation analysis. It designed the control systems of motor drive for drift adjusting system with the improved PID control. The drift angle adjusting system has such advantages as the small space, simple configuration, high position control precision, fine repeatability, self locking property and low powers. It showed that the system could accomplish the mission of drift angle adjusting excellent.

The hyperspectral imager is a kind of camera that can image objects in many narrow spectral bands, and acousto-optic tunable filters (AOTFs) can be used as the optical filtering elements in such instruments. AOTFs have many advantages such as solid-state, small size, good environmental adaptability, programmable, electronically control and so on, which are suitable for space exploration. For instance, AOTFs have been used in Mars and Venus detection. However, more advantages of AOTFs can be utilized in spectral detection, such as random wavelength access and configurable spectral resolution, and more flexible imagers can be expected with these characteristics. As a result, a new hyperspectral imager based on AOTF has been realized. It can not only take images in the spectral range of 460~1100nm with more than one hundred narrow bands, but also allow users to select any set of bands and configure the spectral resolution in a certain range just by computer commands. To do so, a multi-channel RF generation system is developed to drive the AOTF. When multi RF frequencies are applied to the AOTF simultaneously, not only the central wavelength, but also the bandwidth and the passband shape of the selected band, can be controlled by configuring the RF signals. Such capability enhances the flexibility of hyperspectral imaging, but the increased number of configurable variables complicates the course of calibration, so some specific calibration setups and methods are needed. In this paper, the laboratory calibration of the imager is introduced, and some results are presented and analyzed.

The double Langmuir probe, as a payload of a seism-electromagnetic satellite, has been designed for in situ measurements of the parameters of the ionosphere plasma on the 500km altitude orbit to research the electromagnetic coupling between the solid-earth activities and the ionosphere disturbances. The Langmuir probe is comprised of two spherical sensors: the diameter of the smaller one is 1cm and the other one is 5cm. The two sensors are mounted on two parallel booms on the satellite, which are half meter far from each other. The two main ionosphere parameters measured by the Langmuir probe are electron density and electron temperature, which are computed from the I-V curves. The I-V curve is given by a current flow through a sensor in case of a sweep voltage is applied to the sensor. There are three main work models for the Langmuir probe: the normal model, the burst model and the decontamination model. The normal model is for the general measurement of the ionosphere parameters around the globe with 1s time resolution, while the burst model is to measure the ionosphere over the interested areas, like the areas with more earthquake activities, with 0.5s time resolution. The decontamination model would work if the I-V curves shown hysteresis phenomenon, which indicated that the sensors may be contaminated by the outgassing of the satellite. The description of the Langmuir probe instrument and its capabilities is provided.

The Acousto-Optical Tunable Filter (AOTF) is an electronically tunable optical filter based on Acousto-optic effect and has its own special compared with other dispersive parts. Because its characteristics of electronic tunable spectral selection, rapid response and simple structure, imaging spectrometer based on AOTF is a useful high-spectral technology, especially in deep space exploration applications. This paper introduces two imaging spectrometers, a VIS-NIR Imaging Spectrometer (VNIS) built as a payload instrument for lunar detection and a whiskbroom imaging spectrometer (WIS) with programmable spectral sampling. VNIS provides programmable spectral selection from 0.45 to 2.4 μm and includes two channels, a V-NIR hyper-spectral imager (0.45 to 0.95μm) and a SWIR spectrograph (0.9 to 2.4μm), with a spectral overlap of 0.05μm. WIS is a kind of scanning, spectral programmable imaging spectrometer, includes a scanning mechanism and a programmable spectral selection spectrometer. In the end, the prospects in deep-space exploration application are discussed.

Space-borne hyper-spectral imagery is an important means for the studies and applications of earth science. High cost efficiency could be acquired by optimized system design. In this paper, an advanced scanning method is proposed, which contributes to implement both high temporal and spatial resolution imaging system. Revisit frequency and effective working time of space-borne hyper-spectral imagers could be greatly improved by adopting two-axis scanning system if spatial resolution and radiometric accuracy are not harshly demanded. In order to avoid the quality degradation caused by image rotation, an idea of two-axis rotation has been presented based on the analysis and simulation of two-dimensional scanning motion path and features. Further improvement of the imagers' detection ability under the conditions of small solar altitude angle and low surface reflectance can be realized by the Ground Motion Compensation on pitch axis. The structure and control performance are also described. An intelligent integration technology of two-dimensional scanning and image motion compensation is elaborated in this paper. With this technology, sun-synchronous hyper-spectral imagers are able to pay quick visit to hot spots, acquiring both high spatial and temporal resolution hyper-spectral images, which enables rapid response of emergencies. The result has reference value for developing operational space-borne hyper-spectral imagers.

Acousto-optic tunable filter (AOTF) is an electronically tunable optical filter which can make optical beams passing through the acousto-optic (AO) crystal manipulated by suitable frequency generated acoustic waves. In view of the advantages of AO devices such as compact, solid-state, easily integrated, extremely fast response and tunable wavelength output, the AOTF spectrometers have been widely applied in space-based instruments. Considering the operation of the devices in the naturally occurring space radiation environment is one of the major space qualification issues nowadays, the research on characteristics of AOTF in the space radiation environment is significant. Focusing on the space radiation effects on AOTF, especially for radiation environment that lunar exploration infrared imaging spectrometer based on AOTF needs to carry on, the space radiation characteristics of AOTF has been studied through the radiation experiments and the AOTF performance tests. In this paper, some details of AOTF performance tests like detecting principle, method, equipments and performance indicators are introduced firstly. Then the radiation experiment of AOTF is described, while the measured data such as optic transmission, the relationship between diffraction efficiency and driving power, diffraction efficiency and driving frequency, diffraction wavelength and driving frequency relations before and after experiment are analyzed comparatively next. Finally the experimental results are presented and evaluated.

Star pattern recognition is one of the key problems of the celestial navigation. The traditional star pattern recognition approaches, such as the triangle algorithm and the star angular distance algorithm, are a kind of all-sky matching method whose recognition speed is slow and recognition success rate is not high. Therefore, the real time and reliability of CNS (Celestial Navigation System) is reduced to some extent, especially for the maneuvering spacecraft. However, if the direction of the camera optical axis can be estimated by other navigation systems such as INS (Inertial Navigation System), the star pattern recognition can be fulfilled in the vicinity of the estimated direction of the optical axis. The benefits of the INS-aided star pattern recognition algorithm include at least the improved matching speed and the improved success rate. In this paper, the direction of the camera optical axis, the local matching sky, and the projection of stars on the image plane are estimated by the aiding of INS firstly. Then, the local star catalog for the star pattern recognition is established in real time dynamically. The star images extracted in the camera plane are matched in the local sky. Compared to the traditional all-sky star pattern recognition algorithms, the memory of storing the star catalog is reduced significantly. Finally, the INS-aided star pattern recognition algorithm is validated by simulations. The results of simulations show that the algorithm's computation time is reduced sharply and its matching success rate is improved greatly.