This PDF file contains the front matter associated with SPIE Proceedings Volume 11570, including the Title Page, Copyright information, and Table of Contents

The field of laser remote sensing and laser detection is becoming a research hot spot. Filter wheel is an important part in the process of remote sensing. The purpose of filter wheel is to choose the proper band wavelength of light to realize the specific functions. The paper made a design scheme of a type of filter wheel component and then did structural analysis under different and strict load cases. These various load cases were used to prove that if the component could be safe during the launching time of the rocket. For the initial design scheme, the situation was not good. After that, the paper made an improved design by using special flexible supports, which had flexible links and support glue. At last, structural analysis was made. The result of analysis showed that the improvement was effective and successful.

At the same orbital height, the radiation environment in SAA region is worse than that in other regions. The main difference is that the region contains high energy particles. CCD star sensors has been developed for use in the attitude determination and control system of satellites, we have processed star sensors flight data and star images acquired by satellites in orbit in an attempt to characterize the performance of CCD star sensors in the abnormal region of the South Atlantic. This paper also introduces the influence of high energy particles exist in the South Atlantic Anomaly on CCD photoelectric imaging detectors. The abnormal phenomena and generation mechanism in the star images has been analyzed. The improvement measures and suggestions for high precision star sensors to avoid or eliminate the influence of SAA has been given finally, which provides reference for improving the performance of star sensors.

At present, the frequency of human space activities continues to increase, resulting in more and more space debris, which poses a great threat to the working satellite. The collision of debris and satellites may cause abnormal operation of the satellite or even complete damage. Based on the 3u cubic satellite platform, this paper has designed a miniaturized visible light detection system with a full field of view of 12° (9°×7°). the wavelength band of the system is 450 ~ 800nm, the pixel size of the detector is 5μm, the entrance pupil diameter is 60mm, the system focal length is 150mm, the detection system is composed of 8 lenses. Using optical design software to evaluate the image quality of the optical system, the results show that the diffusion spots in each field of view are approximately circular, the maximum RMS radius is less than 7.4 μm, and the energy distribution in each field of view is more than 80% within 3 × 3 pixels, field curvature, distortion all meet the requirements of the detection system. Finally, the tolerance analysis results show that the design has good imaging quality and meets the system performance requirements and machining requirements. The visible light detection system has a large field of view, light weight, low processing cost and high energy concentration. and can meet the demand for space debris detection in Earth orbit.

At present, the accuracy of star sensor calibration based on real space is limited by the factors of vibration, atmospheric environment and so on. In this paper, a new calibration method for digital Time Delay Integrate (TDI) star camera is proposed based on two star cameras joint observation, overcoming the disadvantage mentioned above with high accuracy. Firstly, a mathematic modeling process is introduced with the proposed method. Then an experimental system is set up with two star cameras and an equatorial. Finally, static and dynamic measuring is complemented and errors are analyzed. The results show that, with the proposed method the calibration accuracies of star camera round X/Y axes are 1.45″ (3σ)/0.84″ (3σ), respectively.

The laser communication system with polarized beam splitting is a useful method for interstellar networking. In longdistance communication terminals which adopts a system of common aperture same frequency transmitting-receiving, the stray light comes from the inside system is generated by retroreflectance and scattering, which will cause interference to the reception of signal light. The ability of internal stray light suppression is the main factor restricting the output power of the system signal and the distance of communication chain-establishment. The optical antenna as the key component of the common channel, coaxial optical antennas are replaced by off-axis optical antennas to reduce paraxial stray light. This work designed miniaturized off-axis optical antenna with a large field of view, and combined the YNI factor to analyze the factors affecting the internal stray light. The proportion of stray light generated on each surface was determined through surface modeling and simulation in Tracepro, and the optical antenna was actually tested by constructing optical path. The test result 71dB is close to the simulation result73dB. It indicates that the off-axis angle and YNI factor can be used to characterize the isolation indicator of optical antenna. We believe this work is of great significance for guiding the rapid design and indicator analysis of the system, meanwhile provides reference for other systems of stray light suppression.

In order to realize MTF detection without collimator, first establish an auto collimate detect system, analysis its principles and requirements. Then, simplify its optical path , give the formula of reflexed direction angle of target fringes, give the formula of its effect on MTF. Compare the coaxial system and off-axial system: target deflection caused the test MTF to drop to 87.9% of the actual MTF. Give the design method of autocollimation target, using this method, for an off-axis camera, the MTF test error due to target deflection can be reduced from 12.1% to a negligible level. Finally, discusses the splicing of detector and target, analysis the effect of filter on focal plane, propose the confocal design and splicing.

Aiming at the threats to spacecraft safety caused by space debris, and improving the stability and working life of spacecraft in orbit, it is proposed to use spacecraft equipped with a safety self-perceptual optical payload to detect space debris to improve the safety of the aircraft in orbit. This paper analyses the application methods and characteristics of the safety self-perceptual optical payload of space vehicles, and defines the technical indicators of the optical payload. The safety self-Perceptual optical payload includes the MWIR optical system with large field of view and the visible continuous zoom lens with large zoom ratio. The detector resolution is 1280×1024, the pixel size is 15μm, the focal length is 8mm, the F number is 2, and the field of view is 97.6°×85° of MWIR optical system；The detector resolution is 1920×1080, the pixel size is 5.5μm, the focal length is 15mm~750mm, which has a 50 times zoom ratio, and the field of view is 38.8°×22.4°~0.80°×0.45° of the visible continuous zoom lens. The two systems are athermal designed in the temperature range of -40°C~60°C respectively to meet the environmental requirements of space applications. Safety self-perceptual optical payload could obtain, and apperceive long-range targets in the 10km range around the space vehicle, and improve the aircraft's survival ability

With the rapid development of modern optical detection technology, higher requirements are put forward for optical detection equipment. Whether it is a ground optical measuring instrument or a space detection camera, it is necessary to reduce or avoid the measurement performance degradation caused by the interference of strong light sources such as the sun.It briefly introduces the current application development of the sunshade deployment mechanism, comparatively analyzes some problems of the current application schemes, and proposes a design scheme of the ropes driven sunshade deployment mechanism. The traction of the constant pressure exhaust valve during the first deployment stage can be achieved by rope traction, which can quickly realize the air pressure balance between the target instrument to be sealed and the external environment, and can avoid the air pressure shock caused by the sealing failure in the initial deployment stage of the sunshade deployment mechanism; Rope traction can effectively control the speed of the unlocking process in the second stage of deployment, reducing the shock of the unlocking moment again; In the third stage of deployment, locking of the deployment joint can be achieved by rope traction, and locking backup can be effectively achieved. This kind of ropes driven sunshade deployment mechanism has the advantages of not only controllable deployment process, small shock, but can be used repeatedly without damaging or destroying the original deployment locking mechanism, and is especially suitable for ground measuring equipment and the ground repeated principle verification of space detection instruments.

When aligning telescopes is difficult to align precisely if the optical system with large view filed, long focal length and large-aperture. Application of reverse optimization analysis method to guide optical alignment in previous of computer-aided alignment has been proposed, namely, the theoretical and the numerical analysis were given by use software. Simulating of three-mirror off-axis optical system was carried out using reverse optimization method. The sensitivity matrix of the mirror directs the priority of adjustment freedom. Calculating the precision of primary alignment can not only reduce alignment time, but also providing the design proof for optic-mechanical design.

Organic molecules are the main contamination source of space payloads on orbit, and they need to be removed as much as possible on ground phase. In this paper, based on the vacuum outgassing rules of nonmetal materials and the outgassing methods of satellite materials, a simple, high-efficiency, low-cost test method for outgassing of space contamination sensitive instruments was proposed. In the method, the requirements of test equipment, test conditions, terminal criteria, and outgassing effect evaluation were presented. Using this method, several common nonmetal materials were tested for outgassing. The results show that the method is efficacious.

Time delay and integration (TDI) CCD or CMOS sensors are widely used in space cameras to realize high resolution. Fixed TDI stages are often used when space cameras are working to avoid image saturation. As a result images obtained have problems such as short of digital number levels. In this paper an automatic on-orbit adjusting TDI stages method of space camera based on sun zenith angles was put forward. In this method radiance at entrance pupil of space camera was calculated in real time by nonlinear function fitting according to sun zenith angles of ground targets. Then optimal time of exposure could be obtained. Line transfer time for image compensation was calculated at the same time. Finally TDI stage was acquired by optimal time of exposure and line transfer time. In this way real-time calculation and adjustment of TDI stages were realized. Results of comparison of simulation by STK and computation by MODTRAN indicate that standard deviation of radiance fitting errors is about 0.175W/m² ∙s and relative radiance fitting error is no more than 0.93% as sun zenith angle belongs to [5°, 65°]. Dynamic changes of SNR along with changes of time and sun zenith angle using adjusting TDI stages method and fixed TDI stages method were compared and analyzed. Results of analysis indicated that SNR would be improved from 23 dB to 39dB as sun zenith angle was 88.2° when automatic on-orbit adjusting TDI stages method was used in comparison with fixed TDI stages method.

Multi-frame blind deconvolution (MFBD) is a well-known numerical restoration technique for obtaining highresolution images of astronomical targets through the Earth’s turbulent atmosphere. The performance of MFBD algorithms depend on initial estimates for the object and the PSFs. Even though the observed image might be close to the object and could be used for the initial estimate for the object, as is often the case with the PSFs, we lack prior knowledge on the PSFs for each image. In order to provide high-quality initial estimates and improve the performance of the MFBD algorithm, one of the most effective methods is to introducing an imaging Shack-Hartmann Wave-front sensor which is similar to the traditional Shack-Hartmann Wave-front sensor but with a smaller number of lenslets across the aperture, and to process the data using a multi-channel joint restoration algorithm. In this paper, we proposed a multi-channel joint restoration algorithm which involves the usage of an imaging Shack Hartmann channel data alongside with the science camera data to improve the overall performance of the MFBD restoration algorithm. The numerical results are given in order to illustrate the performance of the joint restoration process.

A full-sky autonomous star map identification algorithm based on radial and cyclic features is proposed. The algorithm defines a star pattern, composed of radial angular distances and circular angles. Then, a three-step strategy is adopted to find the correspondence of the sensor pattern and the catalog pattern, including initial lookup table match, cyclic dynamic match, and validation. A number of experiments are carried out on simulated and real star images. The simulation results show that the proposed method provides improved performance, especially on robustness against up to 6 false stars. Also, the average identification time is about 45ms, and memory requirement is 16MB, having a good satisfaction to the requirements of the target system.

Solar Array Drive Assembly(SADA) is a core component of high-power and long-life satellites, and the shafting is an important part of SADA. Its vibration characteristics analysis is very important in structural design and dynamic analysis. The paper theoretically derived and calculated the natural frequency of the shaft system under the action of bearing preload and span, and established a corresponding finite element simulation model in ANSYS. It is concluded that the natural frequency of the shafting increases with the increase of the bearing preload and the span, and the influence of the bearing span is more significant.

Distributed reconfigurable remote sensing satellite system can realize flexible and robust remote sensing network. Imaging system for distributed reconfigurable remote sensing satellite system should consume fewer power and be lighter to be installed on small or micro satellite. In this paper imaging system based on CMOS for distributed reconfigurable remote sensing satellite system was put forward. Circuits of CMOS sensor driving and CMOS data processing were detailed. In order to improve signal integrity circuits were divided into two sections which were connected with flexible printed circuit. CMOS sensor and its power circuits were placed in the focal plane printed circuit board. Imaging control box consisted of control and data processing circuits of CMOS sensor as well as communication and image data transferring circuits. Impedance matching was used to improve signal integrity of signals transmitted through flexible printed circuit between the focal plane printed circuit board and imaging control box. Results of experiments and analysis indicated that power dissipation of imaging system for distributed reconfigurable remote sensing satellite system was 4.05 W and the weight of imaging control box was 0.435 kg. SNR of each band of imaging system for distributed reconfigurable remote sensing satellite system was more than 41.28 dB as sun zenith angle is 20º and earth reflectance is 0.65.

The surface contribution analysis method is to find the wavefront map at the local intermediate entrance and exit pupil reference spheres for each optical surface. Direct pictures of each surface aberration contribution are then given by fitting the wavefront errors with Fringe Zernike polynomials which can help optical designers to find the origins of the main aberrations at the final focal plane and make them choose the effective variables for optimization consciously, which is very helpful for designing the freeform optical system with hundrands of variables. This paper discusses the surface contribution analysis method. A Matlab routine is written to communicate with Code V and to give direct pictures of aberration contribution for each surface. A compact freeform optical system is designed to validate the surface contribution analysis design method which is proved to have good convergence and very directive for optical designers.

The microchannel-plate-based x-ray optics is a spherical crown containing millions of square microchannels, reflecting the small incident angle light at a certain angle through the inner wall of the channels. Structure defects may exist in the square microchannel array. In this paper, the effects of structure defects on the imaging performance were studied through simulation and MPO preparation experiment. The structure defects involved in the paper include two types, chamfered channels and tilting channels. The experimental results are consistent with the simulation images, proving that the simulations are correct. The results show that the imaging of MPO with standard square channels array is a symmetrical cross. The presence of chamfers in corner of the channels results in a weak secondary small cross in the 45° direction of the obvious cross. For the case that the channels are tilted slightly, the center of the cross deviates from the imaging center, and the cross becomes an asymmetric cross. This study provides a theoretical guidance for precise control of array structures in the preparation of MPO.

This paper investigates a novel quality inspection method for the components with small diameter and deep aperture. A method for extracting the minimum circumscribed rectangle of the target is proposed, which would provide additional shape and angle information and avoid unexpected overlaps and background disturbance. In order to detect the low contrast targets in complex background, a novel method based on Faster R-CNN with several improvements is adopted. In the framework, a five-dimensional (5-D) vector is designed to represent the minimum circumscribed rectangle followed by an improved anchor selection mechanism in the region proposal network. Furthermore, an improved POI pooling process is employed to extract feature maps. Comparison experiments fully demonstrate the superiority of the proposed inspection method over existing methods. Meanwhile, successful inspection results on challenging real-world images prove that the system is of practical significance to industrial applications.

This paper proposes a improved method for measuring the focal length of a telephoto lens. In this paper, a photoelectric theodolite with high accuracy of angle measurement is used. Besides, a CMOS camera is used to take a position image of the center point of the theodolite, and the corresponding azimuth displayed by the theodolite is recorded. Leveling the optoelectronic theodolite on the open field, Polaris is used as a point light source outdoors. Adjusting the point target on the CMOS image, by which the target is placed in the view center of the field (crosshair center). And then, the pitch and azimuth data of the device are recorded. Adding disturbance to the photoelectric theodolite, the CMOS images is recorded. Adapting methods of target feature segmentation, sub-pixel positioning is performed on the point target image which captured by the CMOS camera. And the point target coordinates is obtained. Finally, the result based on the theodolite angle offset, sub-pixel offset and elevation angle data is calculated. The perturbation data is averaged to calculate the focal length of the telephoto lens. Compared with equipment testing result of focal length, experiments have achieved high measurement accuracy. And this method is suitable for detecting the focal length of an optoelectronic device in an outdoor environment.

To help China's first Mars mission go smoothly and improve the performance of the solar cells mounted on the rover in illumination conditions on the Martian surface, the project team launched a study to simulate the sky light on the Martian surface.This paper focuses on the influence of Martian sky light on solar array output at different solar elevation angles and light depths.Based on the approximate model of sky light radiation, a set of sky light simulation equipment on the surface of Mars is developed.The advantages and disadvantages of using LED light source and metal halide light source to simulate sky light are compared and analyzed.The sky light simulator can simulate the sky light with the solar elevation Angle of 75°, 60° and 45°, and the sky light with the optical depth of 0.9, 0.7 and 0.2.According to the requirements of the test department, the simulation effect was tested with instruments such as spectrometer.The test results were approved by the test department, and the skylight simulator has been applied to subsequent Mars rover tests.

Due to the continuously increasing detection ability in astronomy, polarization aberrations are playing more and more important roles in the performances of astronomical telescopes. In this paper, polarization aberrations of an unobscured off-axis astronomical telescope, which is designed to detect weak gravitational lensing signal, are analyzed via polarization ray trace. The diattenuation map and retardance map of each mirror of the telescope are obtained, and both its Jones pupil and amplitude response matrix are shown. Because of polarization aberrations, the imaging contrast of the telescope is limited to be at a level of 1e-5, and the PSF spatial distribution of the telescope varies, too. Optics ellipticity of the telescope is analyzed. The variations of optics ellipticity, which are dependent of field of view (FOV), are induced by polarization aberrations. The maximum and mean variations of the optics ellipticity in all FOVs are 7.5e-3 and 2.7e-3, respectively. At the FOV [-0.0487°, 0.155°], the maximum ellipticity interpolation error increases from 1.2e-4 to 1.1e-3. According to the analyses shown in this paper, we can see that polarization aberrations in the telescopes which aim to detect weak gravitational lensing signal and demand ultrahigh imaging performance are not negligible. Hence, polarization aberrations should be involved to optimize these telescopes.

With the development of national economy and the advancement of aerospace technology, modern aerospace optical remote sensors are becoming more and more complex systems with diverse functions and performance, at the same time, there is clear demand for rapid response. Traditional design methods can no longer meet the development requirement of modern aerospace optical remote sensors, so the new methods are urgently needed. Based on Siemens PLM software Teamcenter, this paper carried out the rapid development research of the full life cycle of the apace remote sensors, and established a collaborative design environment from index requirements to optical design, structural design, simulation analysis, and three-dimensional annotation and achieved system engineering, structural design, optical design, CAE design collaboration. First of all, the remote sensor demand and system index management environment were established on the TC environment, and the system index was transferred to the optical design. Secondly, based on the XML technology, the one-key update of the optical design parameters to the mirror skeleton model of the remote sensor was realized, which accelerated the iteration process of optical design and structure design. Third, based on the CREO skeleton modeling technology, realized the Top-Down design of complex optical remote sensors, improved the efficiency of collaborative design of structural design. Further opened up the multi-source data management link, realized structural design and simulated the full life cycle of data analysis management. Then, using 3D annotation technology, the 3D model was directly shipped to the factory, which improved the true transfer of design intent, shortened the drawing cycle and improved production efficiency. Finally, taking the development of a complex optical remote sensor as an example, the practical application of collaboration design was given. The research results show that based on TC collaborative design method were practical and feasible in the design of an aerospace remote sensor, and had good application prospects, which can significantly improve the design efficiency of the remote sensor and shorten the development cycle.

With the advancement of technology, miniature projector equipment has become the mainstream direction of the projection display industry. Designing an efficient and lightweight LED lighting system is the focus of the lighting part of the mini projection lighting system. This paper designs a miniature projection lighting system, which consists of LEDs, TIR lens, fly’s-eye lens, relay lens and so on. Firstly, based on the theory of non-imaging optics, the mathematical formulas of the collimated small-angle refraction surface and the collimated large-angle reflection surface of the TIR lens are derived, and a program is calculated in the MATLAB to obtain a series of TIR lenses. Discrete points and the discrete points obtained in MATLAB are imported into the 3D modeling software SOLIDWORKS to obtain the 3D model of the TIR lens, and the 3D model is imported into LIGHTTOOLS for modeling and simulation. The simulation results show that the divergence angle of the light of the TIR lens is within 5 degrees, which meets the design requirements. Next, the theory of the fly’s-eye lens is elaborated and the formula of the double-row compound eye lens is deduced in detail. Finally, based on the design of the TIR lens and the fly’s-eye lens, the focal length of the relay lens is calculated. The relay lens is also designed in ZEMAX. In the process of designing the relay lens, the influence of the aberration of the imaging system on the image quality is considered. The spherical aberration, coma aberration, field curvature and other aberrations of the lens are optimized, and finally the relay lens conforming to the design is obtained in ZEMAX. Finally, the TIR lens, compound eye lens, and relay lens are imported into LIGHTTTOOLS for modeling and simulation. A rectangular light spot with a uniformity of more than 90% is obtained, and the lighting system is compact. which meets the design requirements.

GAOFEN-4 is a high-resolution optical remote sensing satellite on geosynchronous orbit, which has been found the potential to monitor the moving ships on the sea. Some classic moving ships target detection algorithms are studied. A new algorithm is proposed for the sequence images of GAOFEN-4 satellite, which can effectively suppress the interference of noise on moving ships target detection by performing the defogging of dark channel prior and a moving detection with visual background extractor. Some experiments are executed with real sequence images. It shows that the new algorithm is better than classic target detection algorithms for the sequence images.

An attempt has been made to propose a flexure-based support of the high-precision base plates on Hard X-ray Imager (HXI), which is designed to investigate the non-thermal high-energy electrons accelerated in solar flares. This flexure support is designed to compensate thermal strain, which can lead to an unacceptable reduction of surface accuracy under rigid constraint. The flexure support proposed in this article is made up of eight separated single-side filleted flexure leaves, which are small and easy to manufacture. The flexure leaf’s compliance matrix is derived from Castigliano’s second theorem. Then the matrix is used, along with Finite Element Analysis (FEA), to determine the critical dimension of the flexure leaves. According to the result of finite element simulation, under a temperature change of ±5K, the inplane torsion angle of the installation sites of grids are reduced to within 10 arcsec using flexure support. And the firstorder natural frequency of the base plate with flexure support is 184 Hz, which is higher than the natural frequency and external disturbance frequency of general satellite carriers.

The precise alignment of the space telescope with an active secondary mirror (ASM) is a key factor to ensure the imaging quality. The traditional alignment methods, like sensitivity table method and SPGD, are not suitable for on-orbit instant alignment of space telescope. In this paper, a model-based wavefront sensorless adaptive optics (WSLAO) method is proposed for the alignment of ASM of space telescope. This method does not require an additional wavefront sensor (like Shack-Hartmann) or a lot of iterations (like phase retrieval). The low spatial frequency content of images is used as the metric function. The misalignment errors can be estimated from the quadratic relationship between the metric function and the coefficients of gradient orthogonal modes (GOM). Here GOM is derived from the response functions of five degrees of freedom of the ASM. A three-mirror anastigmatic telescope with an ASM is modeled for the performance tests. Simulation results show high corrective accuracy and rapid convergence of our method. The RMS of the residual aberration can be reduced to less than 0.02 rad after three correction cycles.

With the continuous development of optical technology in recent years, the pace of human exploration of space has further accelerated. Space remote sensing technology is widely used in surveying and mapping, environmental monitoring and other fields. Therefore, the requirements for space optics technology are gradually increasing. In order to reduce the launch cost and the deformation of the supporting member and the main mirror base under its own gravity, a lightweight design must be carried out. Therefore, under the premise of ensuring the rigid body displacement of the mirror body and the error of the mirror shape, lightweight has become a key requirement for the development of remote sensing technology. By comparing various supporting structures, the spatial freedom of the mirror is calculated. Choose a combination of 9-point post-support and 3-point peripheral support. Compare and select the materials commonly used in the structure of the supporting part and the main mirror base. Although the support structure adopts topology optimization, a very effective support method can be obtained, but the final result cannot be universally applied to the support structure of mirrors with different apertures. Therefore, this paper determines the design structure of the relationship between the mirror support position, the fundamental frequency and the surface shape accuracy and the support structure parameters based on the flexibility matrix. For the rigid parts of the supporting structure and the main mirror base, simulation software was used to optimize the design of the initial design structure to remove excess materials. The final main mirror base lightweight rate was 36.6%, and the triangular plate lightweight rate was 65.9%. The static analysis and modal analysis of the supporting scheme are carried out by analysis software. After optimization, the shape accuracy of the primary mirror under its own weight is better than λ/50. Structural resonance will seriously affect the use and life of the equipment. Therefore, the modal analysis is performed, and the fundamental frequency is within a reasonable range during the optimization process. The simulation results show that the first-order fundamental frequency is 836.55 Hz. The analysis results show that while ensuring the shape accuracy of the primary mirror, the lightweight design of the mirror support assembly is realized.

This article, which is based on the topology optimization theory, considered the lightweight design of large aperture reflectors. Firstly, the material selection is based on the low temperature environment and the low temperature infrared optical mechanical structure design principles. Then, by using the minimum deformation of the mirror surface as the objective function, mirror volume and rigid body displacement as design restraints, and imposing manufacturing constraints, a conceptual design of the mirror back with manufacturability was accomplished. Finally, by using the finite element analysis method to compare the performance of the topologically optimized mirror and the primal mirror, it shows that the topologically optimized mirror met the design requirements in terms of lightening effect and structural rigidity, and the surface figure met the requirements under the influence of gravity, which emphasizes the feasibility and practicality of topology optimization in the large aperture mirror’ design.

Nanosatellites usually refer to satellites with mass less than 10 kg and practical functions. With the development of high and new technology and the promotion of demand, nanosatellites play an important role in scientific research, national defense, commercial and other fields with the advantages of small size, low power consumption, short development cycle, formation networking and low cost to complete many complex space tasks. High resolution remote sensing is one of the important applications of microsatellites, because of its small size, it requires more for optical payload. According to the structural form of RC system, this paper presents a compact coaxial four reflection catadioptric system based on the structural form of RC system. The final optical system design results are as follows: the focal length is 192.2mm, the pupil diameter is 136mm (the effective pupil diameter is 105mm), the working band is 500-900nm, the imaging field of view is 4.5°, and the total optical length is 58mm. The analysis shows that the transfer function of the optical system is higher than 0.45 at 100lp / mm, the distortion of the whole market is less than 0.12%, and the relative illuminance of the whole field of view is higher than 96%. It is proved that the optical system has good imaging quality in the full field of view, and the system has good compactness to meet the load requirements of micro nanosatellite.

With the continuous development of navigation technology, celestial navigation system has gradually become the essential of celestial navigation system with its advantages of autonomy is strong, good concealment and high precision. The key component of the astronomical navigation system is the all-day star sensor. With the improvement of navigation accuracy, higher requirements have been put forward for the design of all-day star sensor, which is required to be able to work normally within 24 hours. The temperature range of the star sensor working on the airborne platform is very wide, and the temperature has a great impact on the imaging performance of the star sensor, thus affecting the positioning accuracy of navigation. Therefore, it is of great practical significance to ensure that its optical performance does not change within such a wide range of temperature, so as to significantly improve its navigation and positioning accuracy.

Space-based high-resolution imaging system has a trend to broadband spectrum imaging in geosynchronous orbits. The resolution of an imaging system is related to the aperture size, the height of the orbit of the system, and the detection wavelength. For traditional imaging system, it is difficult to increase the aperture size due to the limitation of manufacturing level, processing cost and load weight. The optical sparse aperture (OSA) system uses a number of independent subaperture systems with a smaller size and the same standard to collect light from objects and synthetizes a blur image in focal plane, which can achieve a large equivalent aperture size. However, with the increasing number of the sub-aperture systems, the system structure becomes more complicated, which is difficult to be used in practice. This paper presents an approach to search for an optimal OSA system based on annular pupil structure and reduce the number of sub-aperture systems by rotating the pupil to compensate PSF information and improve the image quality in OSA system. In this paper, a 12-aperture OSA system applied for earth observation in geosynchronous orbit are designed optimally to realize the resolution of 1m. The optimal scheme for rotating the pupil with twelve apertures under the threesymmetric structure was determined, and the MTF of the hexagonal structure was obtained. The simulation results show that the method can be applied to design a OSA system with a rotating pupil, synthesize all images within the rotation period, collect all frequency information, and restore high-resolution images using image restoration techniques.

To ensure the high surface accuracy and high thermal stability of space mirror, a lightweight design for the Φ514mm ULE primary mirror of a space remote sensor and flexible support structure with three-point was carried out. By further optimizing the parameters of the flexible supporting structure, the requirements of the optical index were met. The finite element model of the mirror assembly was established, and the static and dynamic characteristics of the assembly were analyzed. The results showed that the surface shape accuracy (RMS) of the mirror assembly is better than 8 nm under a load case of 1g gravity when the optical axis is level, and the first-order natural frequency of the component is 254 Hz. Finally, a mechanical test was carried out on the mirror assembly. The test results showed that the first-order frequencies of the three directions of the mirror assembly are all greater than 100 Hz , the error between the test data and the finite element analysis results does not exceed 10%. Analysis and test results showed that, the reasonable support structure design can effectively lower the change of the mirror surface shape caused by assembly stress and thermal stress, and has good dynamic performance. It is verified that the mirror and its supporting structure designed in this paper are reasonable, which provides reference and ideas for the design of flexible supporting structure of similar space mirror.

With the increasing function density of space optical remote sensor, the integration of visible and infrared space camera has become an important development direction. As the main vibration, the micro-vibration of refrigerator is the key to affect the imaging quality of optical remote sensor. In this paper, three commonly used micro-vibration test methods are compared, and the fixed-support force test method is used to test and analyze the micro-vibration performance of a pulse tube refrigerator under different power and use state. It is pointed out that the strategy of using compressor vibration isolation to mount satellite is more suitable for the Visible and infrared integrated space camera.

A systematic design method for three-mirror anastigmatic (TMA) telescopes with curved image surface is proposed in this paper. The initial structure parameters are solved analytically by the paraxial optical theory and Seidel aberration theory. On this basis, the design method is introduced. Two design examples for on-axis TMA telescope are conducted. One example is curved image surface for mitigate defocus during fine stabilization operations. The other example is curved image surface for configuration design with low misalignment sensitivities. The results demonstrate the feasibility of the design method.