Space optics
2024, 53(3): 20230547.
doi: 10.3788/IRLA20230547
2023, 52(10): 20230065.
doi: 10.3788/IRLA20230065
2023, 52(10): 20230041.
doi: 10.3788/IRLA20230041
2021, 50(11): 20210199.
doi: 10.3788/IRLA20210199
In order to obtain higher angular resolution, the aperture of the space optical telescope is getting larger and larger, and the space telescope with aperture of more than four meters will be difficult to break through the limitation of the effective envelope of the fairing of the existing launch vehicle. On the other hand, the micro-nano optical remote sensing satellite, which has great advantages in terms of development cycle and cost, also has extensive requirements for improving spatial resolution and light gathering area, requiring a smaller launch volume to accommodate a large opto-mechanical system to reduce the launch cost. Deployable space telescopes will be a feasible solution to overcome the limitations of launch size. The research status of deployable space telescopes was reviewed from the aspects of large aperture space astronomical telescopes, segmented mirror deployable telescopes for earth observation and micro-nano satellite optical telescopes deploying along optical axis. Some key technologies and development trends involved in deployable space telescopes were described and summarized.
2021, 50(11): 20210067.
doi: 10.3788/IRLA20210067
With the rapid development of technology and practical deployment of hypersonic weapon, the United States has carried out a new plan of building Tracking Layer of National Defense Space Architecture (NDSA). Firstly, the main design parameters of tracking layer were introduced; Secondly, the analysis model of tracking layer constellation coverage performance, detection capability and tracking performance were established; Finally, the performance of tracking layer was analyzed through simulation and calculation, and the core capabilities such as the minimum satellites number of the whole constellation, detection sensitivity and optimal global target tracking accuracy were deduced. The analysis results have important reference value for the research of data processing algorithm and the design of similar payload and constellation.
2020, 49(11): 20200278.
doi: 10.3788/IRLA20200278
Magnetic field is the most important observed parameter in modern solar physics. The observation and research related to the solar magnetic field are always the front and hot topic in solar and space physics. The development history, current status, and the difficulties in the measurement of solar magnetic field were briefly reviewed. The progress made by Chinese solar community was outlined too. Depending on these reviews, what Chinese solar magnetic field should do in the future international competition was discussed. Based on the advantages of space observation, it is believed that deep-space exploration will play a decisive role in the breakthrough of major scientific problems related to the solar magnetic field.
2018, 47(11): 1113001.
doi: 10.3788/IRLA201847.1113001
To meet the higher demands of the earth and space observation, the aperture of space telescope mirror has took step to 10 m order of magnitude from 1 m with an ever-increasing trend. As a key technology for the space telescope, the large aperture mirror support is related directly to the surface shape accuracy and stability of the mirror, and crucial to the actual observation ability and even the success of the telescope mission. Three main forms of mirror support were discussed and their applicability were compared. The influential factors on the mirror mount design were summarized and based on this summary some key points and principles for support design were discussed. Combined with analysis on support technique research progress at home and abroad, the key techniques such as optimization on the number and location of support points, athermal design and un-stressed assembly and the trend of development were scrutinized. It is expected to provide reference for large space telescope of our country and thus promote leapfrog development in the new round of space exploration.
2018, 47(11): 1113002.
doi: 10.3788/IRLA201847.1113002
Aiming at the problems that the main structure of a mini-optical device in space is too heavy, the ground gravity deformation is too large and the base frequency is too low, the optimization mathematical model was established with the objective of minimum mass and RMS of the random acceleration response, the fundamental frequency and the deformation as the constraint conditions. The topology optimization design of the main structure of the mini-optical device and the engineering analysis of the optimized main structure were carried out. The results show that the mass of the main structure of mini-optical device is 12.5 kg, which is reduced by 68.71%; The fundamental frequency is increased from 11.18 Hz to 268.7 Hz after optimization; The maximum deformation is 0.3 m. The magnification of the acceleration response of the optical-load installation is 1.2 which is better than system specification 1.5. Mechanics and thermal experiments were carried out to examine the performance of the main structure of mini-optical device. The detection results meet the overall index, which proves the main structure has good performance, the optimization method is effective and feasible.
2017, 46(9): 913001.
doi: 10.3788/IRLA201746.0913001
For measuring the stray light level and verifying the ability of stray light suppression of optical remote satellite, the imaging time and orbital characteristic of some satellite were analyed, a scanning system of stray light measuring for optical remote satellite was developed, which was based on a large 7-dimension robot. According to the annual lighting condition of satellite in orbit, the controlling formulae were deduced for all the kinematic mechanism, with the scanning azimuth angle -90-+90, pitch angle -29-+42.5, and their angular accuracy were up to 0.2 and 0.1 separately, the position accuracy was better than 10 mm. Otherwise, an extinction subsystem, which was made was low reflectance material(lower than 1.5% between 400-1 600 nm) and large extinction structure and extinction coefficient could reach 9.910-7, was used to simulate extreme dark target and deep space room. The scanning system of stray light measuring for optical remote satellite can satisfy most optical payload at present for stray light measurement, analysis and verification.
2017, 46(9): 913002.
doi: 10.3788/IRLA201746.0913002
Deep space exploration has great significance for human being to develop and utilize space resources. Remote sensing payload is a very important part of deep exploration. Since the detection distance in the deep space exploration mission is very far, the SNR of the received signals is very low, the capture of extremely weak signals from deep space is a key technology. Based on the requirement of future deep space exploration for ultra weak signal detection, a week signal detection method was given. The method was based on quantum squeezed states, whose shot-noise was less than the standard quantum limit, and some experimental results were given. The result shows that this technique was a promising technology in future deep space exploration. Because the quantum properties of squeezed light is attenuated as the distance increases, in order to be closer to the application, a new laser radar scheme was designed which injected squeezed light at the receiving end, and simulation results were given.
2016, 45(5): 513001.
doi: 10.3788/IRLA201645.0513001
During the onboard imaging process of space camera with large field of view, due to the effects of earth rotation, satellite attitude maneuverings, jittering and other factors, image motion velocity field of the focal plane has a non-linear anisotropic distribution. To overcome this problem, a novel image motion velocity field modeling method which is based on kinematics of rigid body was proposed. In this model, off-axis angle parameter was introduced and formulas of image motion velocity field in the large view off-axis three-mirror system were derived. Taking a certain large field space camera as an example, influences of synchronous and asynchronous velocity matching models on the camera image qualities were analyzed. Results show that, under a constraint of 5% drop and with scroll angle of 15, if integral stages are larger than 10, asynchronous velocity matching models should be adopted. Especially when integral stages are fixed to 32, its dynamic MTF on focal plane can be improved to 0.970 2 while it is 0.340 8 in the synchronous model case. However, synchronous velocity matching model outperforms in the condition of 16 integral stages and 12.3 scroll angle. Onboard imaging experiments proved the accuracy of the models which will provide a reliable basis for large field space camera image motion compensation.
2016, 45(3): 313001.
doi: 10.3788/IRLA201645.0313001
International completed optical/infrared telescopes were reviewed, and the construction of the next generation of telescopes was analyzed, including scientific purposes, optical structure, carry instruments, performance parameters and so on. This paper was focused on the summarization of optical design/diameter and site/orbit of next generation astronomical telescope. Their collaboration observation of ground-based/space-based, modular universal design, observation result big data sharing etc shows the technical characteristics and trend. Combining lessons from abroad with the reality of our country, our own advantages can be formed. Some thoughts and suggestions on long-term planning, private capital opening and others were put forward.
2016, 45(3): 313002.
doi: 10.3788/IRLA201645.0313002
In order to ensure the surface form precision of a mirror whose caliber is 320 mm changes as small as possible before and after bonding, while static and dynamic stiffness of the mirror components meet the requirements, bonding technique of primary mirror in space camera was studied. Firstly, specific bonding parameters of six bonds and round bonds were achieved. Then, the finite element analysis for two bonding options was carried out to analyze static stiffness and optical properties. Finally, when the mirror's surface form precision was 0.030(=632.8), the surface form precision of the mirror was tested. Besides, vibration test of mirror components was conducted. Analysis and experiment results indicate that after using six bonds option to assemble the mirror components, its first order frequency is 144.194 Hz and static and dynamic stiffness meet the requirements. Compared to round bonds option, the surface form precision of the mirror improves 13.5%. This results mean that the six bonds option is better for bonding the mirror whose caliber is near 320 mm.
2016, 45(11): 1113001.
doi: 10.3788/IRLA201645.1113001
Based on the structural complexity and high performance requirements of space remote sensor reflector component, the design method of space remote sensor reflector component was studied. A method which was a combining method with the experience design, the topology optimization design and the size parameter optimization design was put forward, which can make the design result fast convergence, getting the optimal design structure. A reflector component structure design of a space remote sensor was achieved with this method, by means of the finite element analysis techniques, the shape error variation RMS and PV of optical reflector component which characterized the image quality of the component were got, and dynamic simulation calculation was carried out. Finally, the correctness of the finite element analysis results and the rationality of the design were validated by environmental testing. The test results show that the RMS meet the design index under the comprehensive influence of gravity load, thermal load which is in the control range, reflector surface machining residual error and assembly error, and that the overall structure has a high enough dynamic stiffness and reasonable distribution of modal, the dynamic performance of the reflector component is good and meets the application requirement. In view of the reflector components design, this method is an effective and reliable design method.
2016, 45(11): 1113002.
doi: 10.3788/IRLA201645.1113002
Calibration method and process for spatial modulating optical structure composed of quarter wave plate, composite birefringent wedge and polarizer was studied, and the calibrating equations of spectrum and radiation were presented. Based on the polarization principle of spatial modulation, linear least square method for calibration of polarization was provided. By simulation analysis, it is indicated that calibrating accuracy of linear least square method is higher than that of standard fou-point method, the modulating coefficient deviation of linear least square method has the maximum of about 210-4, and moreover, distributes stochastically in the modulating period.
2016, 45(11): 1113003.
doi: 10.3788/IRLA201645.1113003
Aiming at problems such as complicated calibration models and trivial test progress, which are occurred during the calibration of installation error for star sensors, a novel ground calibration method of installation error based on three positions was introduced. Firstly, a mathematical model of installation error was established according to Euler transformation of coordinate systems. Secondly, a new ground calibration strategy of installation error based on three typicall-selected positions on a triaxial precise turntable was put forward. The least square method and three positions method were adopted to conduct simulation contrast experiments. Simulation results demonstrate that calibration result stability of three positions method increases by nearly 10 times than calibration result stability of least square method. Furthermore, three positions method has simplified the calibration test procedure, which has important practical reference value to improve the operational accuracy of star sensor.
