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30 January 2026, Volume 46 Issue 1 Previous Issue   

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Overview of LEO satellite networking communication technology for direct-to-phone connectivity LI Jingling WANG Xianyu, ZHEN Li, MENG Qingzhi, LIANG Wei, MU Tong, CUI Tao, LI Qian, CUI Wanzhao 2026, 46 (1):  1-12.  doi: 10.16708/j.cnki.1000-758X.2026.0005 Abstract ( 367 )   PDF (2682KB) ( 259 )   Save To overcome the limitations of traditional terrestrial communication coverage and establish seamless, all-time, all-domain connectivity capabilities through direct-to-phone connection of integrated space-ground services, this study conducts a systematic review of communication technologies for direct-to-phone connection to LEO satellite networks. Firstly, the application background, concepts and connotations of direct-to-phone LEO satellite network are elaborated. Subsequently, the network architecture for direct-to-phone LEO satellite network is provided, along with the service characteristics and performance indicator requirements for individual and enterprise users. The development trends, comparative strengths, limitations, and technological evolution of the three main technical routes for direct-to-phone LEO satellite network are specifically analyzed. The key issues and technical challenges faced by LEO satellite network are identified, including severe spectrum resource constraint, link limitation and power imbalance, multi-user concurrent access collision, high dynamic spatio-temporal mismatch, and difficulties in ensuring continuity communication. Based on the foregoing analyses, the critical technologies for direct-to-phone LEO satellite network communication are distilled, such as spectrum resource optimization, the evolution of 5G/6G standardized protocols, ultra-large-scale satellite-borne antenna technology, efficient management and control of satellite network resources. Finally, to address the demands of 6G service applications, novel enabling roles of 6G technologies in direct-to-phone LEO satellite networks are proposed, including integrated space-ground architecture, AI-driven optimization, space-based computing networks, and wireless communication-sensing-computing convergence. This review offers a practical and feasible technical direction for the development of direct-to-phone LEO satellite network communication technology. Related Articles | Metrics

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Delay cluster selection optimization based carrier separation algorithm for LEO satellites ZHANG Xu, LIU Pan, HUI Tengfei, LI Jiahong 2026, 46 (1):  13-23.  doi: 10.16708/j.cnki.1000-758X.2026.0006 Abstract ( 86 )   PDF (7569KB) ( 49 )   Save A delay cluster selection optimization based second-order blind identification (DCSO-SOBI) carrier separation algorithm against distortion is proposed to address the demands of complex interference analysis and extraction in low Earth orbit (LEO) internet satellite systems. Targeting the limitations of traditional signal detection and recognition algorithms in handling multi-carrier aliasing scenarios, the proposed algorithm employes blind separation techniques to achieve the separation and extraction of multi-source mixed signals, thereby resolving the feature ambiguity issues caused by time-frequency aliasing of multiple signals. Furthermore, based on the correlation matrix characteristics of the observed signals within the second-order blind identification (SOBI) separation architecture, the proposed algorithm optimizes the initial selection of delay clusters and adjusts the search step size, thereby effectively reducing the search range and computational load of joint block diagonalization (JBD) while improving carrier separation accuracy and convergence speed. Simulation results demonstrate that, compared with the traditional SOBI algorithm, the proposed algorithm exhibits insensitivity to signal types，and achieves a 7.89% improvement in separation correlation coefficient and a 20.81% improvement in residual signal-to-noise ratio (SNR) under a 10dB SNR condition. In terms of computational complexity, the proposed algorithm achieves a significant reduction in the convergence speed of JBD processing at a relatively low computational cost for delay cluster selection optimization. Compared with the Jacobi-like JBD algorithm based on QR decomposition, the required number of iterations is reduced by 10.97%, and the computation time is improved by 0.62ms under a 10dB SNR condition, thereby effectively lowering the computational complexity and processing time required for separation. Without impacting the normal communication of LEO satellites, the proposed algorithm enables highprecision separation and rapid extraction of complex interference signals, providing a foundation for subsequent signal recognition processing and anti-interference scheme decision-making. Related Articles | Metrics

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Peak-to-average power ratio suppression method for OTFS system based on RM coding in satellite-to-ground scenarios SONG Qiangjian, ZHANG Xinyue, ZHU Lidong 2026, 46 (1):  24-35.  doi: 10.16708/j.cnki.1000-758X.2026.0002 Abstract ( 115 )   PDF (8450KB) ( 59 )   Save Orthogonal time frequency space (OTFS) modulation, known for its reliable transmission capability in high Doppler shift environments, has become a key technology for high-mobility communication scenarios such as low earth orbit (LEO) satellite systems. However, as a multicarrier modulation technique, OTFS signals are characterized by a high peak-to-average power ratio (PAPR), which can cause power amplifiers to operate in a nonlinear region, resulting in signal distortion and negatively impacting communication reliability and stability. The Golay complementary sequence, due to its unique properties, ensures that the maximum PAPR of the sequence does not exceed 3 dB. Based on the special relationship between Reed-Muller (RM) coding and Golay complementary sequences, a PAPR reduction method for OTFS systems using RM coding is proposed. At the transmitter, RM coding is used to encode the original bitstream into Golay complementary sequence forms, followed by constellation mapping and OTFS modulation to generate a low-PAPR transmitted signal. At the receiver, to accurately decode this specially encoded signal, a two-step concatenated decoding algorithm is designed. This algorithm combines coset selection decoding and monomial coefficient decoding to achieve error correction for RM codes with Golay complementary sequences, ensuring communication reliability. Simulation results show that, in low earth orbit satellite communication scenarios, the proposed coding method suppresses the peak-to-average power ratio of OTFS system transmitted signals to within 3 dB. Compared with the OFDM system, the OTFS system demonstrates greater robustness. The two-step concatenated decoding algorithm achieves higher transmission reliability at high signal-to-noise ratios (>> 6 dB). This proposed scheme not only provides strong technical support for the application of OTFS modulation in high-mobility satellite-to-ground communication scenarios, but also offers a new reference for PAPR reduction in future multicarrier modulation signals. Related Articles | Metrics

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Anti-eavesdropping scheme for satellite downlink based on CSI and cooperative relay DAI Cuiqin, GUO Haopeng, WANG Hongyun 2026, 46 (1):  36-47.  doi: 10.16708/j.cnki.1000-758X.2026.0007 Abstract ( 61 )   PDF (4880KB) ( 21 )   Save Satellite downlinks face severe eavesdropping threats due to their openness and wide-area coverage. Traditional satellite downlink anti-eavesdropping schemes centered on encryption technology have dual bottlenecks in computational complexity and anti-quantum attack capabilities. Moreover, the application scenarios of existing physical-layer security anti-eavesdropping schemes for satellite downlinks have limitations. To address these issues, an anti-eavesdropping scheme for satellite downlinks based on Channel State Information (CSI) and cooperative relaying was proposed through the cascade design of scrambling codes and coding based on dynamic expansion factors. First, a satellite downlink communication model based on cooperative relaying was established by deploying ground relay base stations to expand the CSI randomness difference between the legitimate link and the eavesdropping link. Second, the expansion factor of the quasi-cyclic low-density parity-check code was dynamically regulated through the CSI of the legitimate link to increase coding randomness and thus increase the decoding difficulty for eavesdroppers. Finally, a scrambling and descrambling mechanism was constructed at the satellite end and the user end using the dynamic expansion factor and the CSI of the legitimate link, so that eavesdroppers could not descramble the confidential information due to the lack of the CSI of the legitimate link. Simulation results show that when the bit error rate at the user end is as low as 10-6, by leveraging the scrambling code's dependence on CSI to construct a descrambling barrier for eavesdroppers, the bit error rate of eavesdroppers can be made to approach 0.5. The proposed scheme, relying on the cooperative design of CSI and ground cooperative relaying, has the potential to resist quantum computing attacks and meets the requirements of satellite communication network engineering deployment for high efficiency and low consumption. It can effectively balance the contradiction between the reliability and security of information transmission in satellite downlinks and can provide a technical reference path with engineering practice value for information security transmission in the future 6G space-air-ground integration scenario. Related Articles | Metrics

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Agile design of satellite systems for large-scale constellations  JIA Xiaodong, CUI Yufu, LIU Jingyu, LI Chunguang, LIU Pengyu, CAO Lijun, XIN Xu 2026, 46 (1):  48-58.  doi: 10.16708/j.cnki.1000-758X.2026.0008 Abstract ( 147 )   PDF (11103KB) ( 123 )   Save In the field of mass production of low-orbit large-scale satellite, the traditional document-based systems design method exists many problems such as insufficient systematization, low iteration efficiency, and difficulties in batch testing. This study aims to construct a kind of agile design method of satellite system based on model-based systems engineering (MBSE) to achieve efficient iteration and batch verification of design process, and short the development requirements cycle of large-scale constellations. This paper gives a technical path combining a multi-level model reuse architecture and an incremental development model. Firstly, a three-level model system (system level-subsystem level-unit level) is constructed. Through the multi-level reuse mechanism of the meta-model library, unit library and architecture library, the design experience is solidified by model. Secondly, an incremental development mode based on use cases is proposed. The requirement changes are mapped to scenario iterations, and requirements are dynamically transferred to indices through SysML models. Finally, a batch testing design method based on system verification models is established, and the traceability matrix between test cases and requirements is constructed to achieve full-link closed-loop verification of design and testing. This research takes the mass production project of optical remote sensing satellites as a case. Through the model iterative of input parameters, the trade-off of subsystem schemes and the verification of mission requirements, the method is verified by engineering case. The application verification shows that the design efficiency is improved by approximately 80%. The MBSE agile design method proposed in this study realizes the digital inheritance of design experience by the model reuse mechanism, solves the problem of efficient response of requirement changes by the incremental development mode based on use cases, and improves the batch verification capability of large-scale constellations by the closed-loop mechanism of test. This research results provide a scalable technical framework for the digital transformation of satellite system engineering and expand the application depth of models in the entire life cycle of satellite mass production. Related Articles | Metrics

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Comprehensive performance optimized design methodology for LEO heterogeneous constellations LIU Siyang, PAN Ruixue, LI Renfei, MENG Tao 2026, 46 (1):  59-72.  doi: 10.16708/j.cnki.1000-758X.2026.0009 Abstract ( 91 )   PDF (8845KB) ( 77 )   Save A comprehensive study is conducted on the design methodology for low Earth orbit (LEO) mega-constellations composed of heterogeneous satellites with diverse functions, orbits and payloads. Three critical challenges are addressed, including nonlinear coverage superposition, differentially coupled drift trajectories, and large-parameter optimization. An efficient semi-major axis decay model is developed under the influence of J2 perturbation and atmospheric drag with combined linear and quadratic fitting. Relative drift compensation equations for both the right ascension of the ascending node and the argument of latitude are derived to maintain orbital stability. A complex optimization model is constructed with the objective of minimizing the integrated manufacturing-launch cost, incorporating multi-dimensional coverage constraints such as revisit time, imaging resolution and coverage stability as well as multi-source engineering constraints including limited fuel, selectable satellites, and multiple mission phases. Key variables are reduced through theoretical analysis to improve computational efficiency. A genetic algorithm is employed to determine the cost-optimal nominal configuration parameters. Furthermore, a closed-loop design framework is developed to coordinate nominal configuration, partial correction, fuel planning, and control implementation throughout the constellation lifecycle. For missions targeting coverage between 30°(N) and the equator, with constraints of ≤10min revisit time and ≤1m imaging resolution, the optimized heterogeneous constellation configuration demonstrates a 26%～30% reduction in total cost compared with uniform configurations. Additionally, temporal consistency of revisit time across different latitudes shows improvement. The performance advantage increases with wider latitude coverage. The optimized methodology enables synergistic optimization of coverage performance and cost, supports scalable design of constellations exceeding 1000 satellites for emergency remote sensing and global IoT applications, and contributes to reduced lifecycle cost and design complexity.  Related Articles | Metrics

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Adaptive teaching-learning-based optimization for multi-satellite collaborative mission planning LIU Yan, LIU Guohua, WEN Zhijiang, HU Haiying 2026, 46 (1):  73-82.  doi: 10.16708/j.cnki.1000-758X.2026.0010 Abstract ( 67 )   PDF (5680KB) ( 30 )   Save To address the insufficient dynamic adaptability in collaborative observation mission planning for low-earth orbit mega-constellations, an adaptive teaching-learning-based optimization algorithm was proposed. Within the teaching-learning framework, adaptive mechanisms and hybrid learning strategies were incorporated. The teaching phase was enhanced through time-varying teaching factors and an elite-guided mechanism, while the learning phase was improved using hybrid learning strategies to dynamically balance global exploration and local exploitation capabilities. Simulations demonstrated that the proposed algorithm outperformed both the improved genetic algorithm and the improved differential teaching-learning-based optimization algorithm in terms of task completion rate and computational time. In large-scale, high-complexity multi-satellite collaborative mission scenarios, it achieved 6% and 16% higher task completion rates compared to baseline algorithms, proving suitable for high-dimensional discrete optimization problems. The algorithm exhibits advantages in task completion rate, operational efficiency, and robustness, making it applicable to collaborative observation missions in low-earth orbit constellations. Related Articles | Metrics

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Mid-to long-wave infrared SNSPD and discussion on its applications in astronomy XU Dingyan, CHEN Qi, ZHANG Labao, WU Peiheng 2026, 46 (1):  83-96.  doi: 10.16708/j.cnki.1000-758X.2026.0011 Abstract ( 75 )   PDF (6814KB) ( 35 )   Save Superconducting nanowire single-photon detector (SNSPD) is a high-performance single-photon detector that can be extended to the mid-to long-wave infrared range. It is highly suitable for astronomical observation missions with requirements of a wide observation range, weak signal detection, and low dark count rates. This article introduces optical response models of SNSPD, establishes a connection between SNSPD parameters and astronomical measures, and describes the development of SNSPD in the mid-to long-wave infrared band. It analyzes the research directions and difficulties from the perspectives of materials, fabrications, device structures, optical enhancement structures, and large array size. It discusses the feasibility of its applications in astronomical detection fields, such as Lidar and exoplanet spectral detection. Finally, it summarizes and looks forward to the development direction of mid-to long-wave SNSPD, highlighting the issues that still need to be resolved, such as further wavelength extension, infrared optical enhancement structures, and miniaturization. SNSPD has achieved saturated internal quantum efficiency at 29μm, but there is still a far way from realizing megapixel arrays and high-detection efficiency devices. With the advancement of micro-nano processing technology and refrigeration technology, it is accessible to achieve high-efficiency mid-to long-wave SNSPD array devices on satellites. Related Articles | Metrics

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Research of technology development for Venus balloon YANG Mei, FU Chenrui, XUE Shuyan, ZHANG Zhengfeng, WEI Yunfei 2026, 46 (1):  97-110.  doi: 10.16708/j.cnki.1000-758X.2026.0003 Abstract ( 125 )   PDF (10409KB) ( 92 )   Save This paper first defines the composition and types of Venus exploration balloons based on the operational environment of Earth observation balloons, then reviews the characteristics of the Venus atmosphere and its impact on balloon technology. Subsequently, the key technical challenges of adapting balloons to the Venusian atmosphere are addressed. Based on existing Venus and Earth balloon technologies, the study explores crucial aspects of design and technology, including payload design, envelope design, energy systems, temperature control, altitude control, and aerial unfolding and inflation methods. For both high-altitude and low-altitude Venus balloons, the research examines the characteristics of the Venusian atmosphere. Above 50 km altitude, the atmosphere of Venus resembles Earth’s environment, making it easier to adapt Earth-based technologies; however, below 50 km, the atmosphere is characterized by high temperature and pressure with insufficient sunlight. The paper summarizes the technological maturity and engineering feasibility, offering a reference for the development of Venus exploration balloons and the implementation of related scientific missions. Related Articles | Metrics

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Simulation andanalysis of Venus aerostat solar cell power generation SHEN Yuxiao, CHEN Kang, YANG Yanchu, DU Qing, WANG Sheng, XU Guoning, 2026, 46 (1):  111-121.  doi: 10.16708/j.cnki.1000-758X.2026.0012 Abstract ( 67 )   PDF (7709KB) ( 47 )   Save The aerostat powered by solar energy is a feasible method for longduration exploration of the surface of Venus. To address the lack of a model for calculating the intensity of solar radiation on the surface of Venus and the power generated by solar cells for the design of the Venus Floater, empirical formulas for the atmospheric transmittance at the Venusian surface at various altitudes are derived from polynomial fitting based on the downward solar radiation flux data measured at different altitudes by the Pioneer Venus Multiprobe. Drawing on the power generation calculation models of photovoltaic cells on Earth, a model for calculating the solar radiation flux on the surface of Venus and the power generation of photovoltaic cells has been established. This model enables rapid and precise simulation of solar irradiance at different altitudes in Venus's complex atmospheric environment. The model is then used to simulate the intensity of solar radiation at altitudes from 0 to 70km in the 0° latitude region of Venus and the solar cell power generation of the Venus Explorer (VE) at altitudes of 0km and 20km on the surface of Venus. The impact of various factors, including date, geographical latitude, flight altitude, and flight attitude, on the power generation of photovoltaic cells is analyzed, which can guide the design of energy systems and the layout of photovoltaic cells for Venus surface aerostats. Related Articles | Metrics

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Cost effective technologies for long range microwave wireless power transmission CHOI Joon-Min , KIM Dae-Kwan, PARK Durk-Jong, YI Sang-Hwa, KIM Dong-Min, KOD ae-Ho 2026, 46 (1):  122-134.  doi: 10.16708/j.cnki.1000-758X.2026.0001 Abstract ( 116 )   PDF (9075KB) ( 38 )   Save Space-Based Solar Power (SBSP) presents a promising solution for achieving carbon neutrality and Renewable Electricity 100%(RE100) goals by offering a stable and continuous energy supply.However,its commercialization faces significant obstacles due to the technical challenges of long-distance microwave Wireless Power Transmission(WPT) from geostationary orbit.Even ground-based kilometer-scale WPT experiments remain difficult because of limited testing infrastructure,high costs,and strict electromagnetic wave regulations.Since the 1975 NASA-Raytheon experiment,which successfully recovered 30kW of power over 1.55km,there has been little progress in extending the transmission distance or increasing the retrieved power.This study proposes a cost-effective methodology for conducting long-range WPT experiments in constrained environments by utilizing existing infrastructure. A deep space antenna operating at 2.08GHz with an output power of 2.3kW and a gain of 55.3dBi was used as the transmitter.Two test configurations were implemented:a 1.81km ground-to-air test using an aerostat to elevate the receiver and a 1.82km ground-to-ground test using a ladder truck positioned on a plateau.The rectenna consists of a lightweight 3×3 patch antenna array(0.9m×0.9m),accompanied by a steering device and LED indicators to verify power reception.The aerostat-based test achieved a power density of 154.6mW/m ,which corresponds to approximately 6.2% of the theoretical maximum.The performance gap is primarily attributed to near-field interference,detuning of the patch antenna,rectifier mismatch,and alignment issues.These limitations are expected to be mitigated through improved patch antenna fabrication,a transition from GaN to GaAs rectifiers optimized for lower input power,and the implementation of an automated alignment system. With these enhancements,the recovered power is expected to improve by approximately four to five times.The results demonstrate a practical and scalable framework for long-range WPT experiments under constrained conditions and provide key insights for advancing SBSP technology. Related Articles | Metrics

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Space 3D multi-extended target tracking based on Gaussian process PHD filter LAN Yu, WU Jianfa, WEI Chunling 2026, 46 (1):  135-144.  doi: 10.16708/j.cnki.1000-758X.2026.0013 Abstract ( 60 )   PDF (2999KB) ( 36 )   Save In tasks such as space warning, evasion, and surveillance of noncooperative targets, the accurate acquisition of detailed information about targets requires simultaneous estimation of both their motion state and shape characteristics. Therefore, research on extended target tracking algorithms is critical. To address this situation, a novel algorithm of extended target tracking suitable for three-dimensional orbital space is proposed. Firstly, a non-parametric modeling approach based on Gaussian process (GP) radial functions is used to model three-dimensional shapes, effectively solving the problem where random matrix models fail to describe complex shapes accurately. Secondly, a probability hypothesis density (PHD) multitarget tracking filter based on the random finite set (RFS) theory is explored. The RFS theory is employed to leverage its benefits, including the elimination of explicit data association, and to effectively handle high-density clutter in space. Finally, a dynamic threshold partitioning strategy based on an improved Euclidean distance is proposed. This strategy which significantly enhances computational efficiency while ensuring tracking accuracy. The simulation results demonstrate that, compared with the extended object tracking algorithm based on the random matrix method, the proposed GP-PHD filter exhibits significant improvements in both target state estimation accuracy and 3D shape description. In terms of shape description, the IOU metric demonstrates an enhancement of 64%. This method effectively overcomes the limitations of traditional tracking methods in orbital space and provides a new technical solution for noncooperative target tracking in space. Related Articles | Metrics

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Pointing control for capture and visual tracking of a spaceborne two-axis turntable WANG Lijiao, TAO Jiawei, WANG Shuyi, LEI Yongjun 2026, 46 (1):  145-156.  doi: 10.16708/j.cnki.1000-758X.2026.0014 Abstract ( 52 )   PDF (5380KB) ( 31 )   Save The pointing control strategy for the whole tracking process of a non-cooperative object via a two-axis turntable-based spacecraft is investigated, ranging from initial target acquisition to the subsequent visual tracking process. At target capture phase, considering camera installation errors and non-coincident centers of multiple-channel fields of view, the kinematic relationship of the image space is exploited and the pointing error of the camera is mapped to the attitude offset of the turntable. This enables high-precision target attitude calculation when the camera's line of sight is not perpendicular to the turntable's end axis, conquering the difficulty in deriving the analytical solution by the traditional method. At visual tracking phase, for the transient performance in the initial tracking stage, a self-adjusted image-plane trajectory planning scenario is developed based on the velocity constraint and the position deviation in the image space. To ensure the smoothness during the switching of multiple channels, a unified coordinate system in the focal plane is introduced by leveraging the consistency of the physical positions at the switching point. A visual feedback control protocol is then constructed based on a novel image-position observer, eliminating the dependency on image-space velocity measurements. To further optimize the control logic, the weighted forgetting factor is utilized in the visual controller design for a seamless connection of the two control stages，meeting the transient velocity constraint and enhancing the robustness of the control system. As for validation and application, the effectiveness of our methodology is verified through physical experiments and on-orbit applications. The high performance for the whole tracking process of the moving target is achieved by the cooperation of the aforementioned schemes. Therefore, the scheme solves the full-process pointing control problem of satellite-borne turntables under the constraints of camera imaging, and bears strong engineering practicability. Related Articles | Metrics

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Orbital design and analysis for an elliptical-orbit satellite to chase an out-of-plane target LIU Xiao, HUANG Jingmei, WANG Rui , ZHANG Xiaowei, WANG Jingji 2026, 46 (1):  157-168.  doi: 10.16708/j.cnki.1000-758X.2026.0015 Abstract ( 62 )   PDF (5004KB) ( 71 )   Save In order to solve the problem of large elliptical inclined orbit satellite's high fuel consumption in the acquisition of space debris from different planes, an orbital acquisition strategy using electric thruster to adjust the orbital plane is designed. The whole orbit acquisition process is designed in three stages. In the first stage, an apsidal rotation maneuver is executed. Subsequently, a single- or dual-elliptic transfer strategy is employed, applying finite thrust control at either the perigee or apogee. This approach enables adjustment to the target orbit using minimal impulses within a shorter timeframe, thereby achieving partial phase chasing. In the second stage, the continuous low-thrust electric thruster is used to exert continuous control at the intersection of the orbital plane, adjust the orbital plane, and enter the orbital plane of the target space debris. In the third stage, phase terminal correction is performed at the apsis, and the semi-major axis deviation adjusted in the first phase is corrected. The control timing and corresponding speed increment of the whole orbit acquisition strategy are given through detailed theoretical derivation, and particle swarm optimization is used to optimize the number of orbit changes in the second stage. Finally, numerical simulations validate the strategy's effectiveness, demonstrating that the fuel consumption for electric propulsion-based out-of-plane orbital transfer under identical conditions is only 3.56% of that required by chemical propulsion. This approach significantly enhances fuel efficiency while maintaining mission precision. Related Articles | Metrics

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Fast signal recapture algorithm for strong star assisted weak star in high orbit receiver ZHANG Chunjie, GE Jian 2026, 46 (1):  169-177.  doi: 10.16708/j.cnki.1000-758X.2026.0016 Abstract ( 51 )   PDF (1325KB) ( 19 )   Save To capture weak navigation signals from the opposite side of the Earth, receivers operating in geostationary orbit and higher altitudes must use long coherent integration time. However, the application of long coherent integration time leads to an excessive number of search units during signal acquisition. For high orbit receivers, the probability of receiving the main lobe signal from a navigation satellite is relatively high. When the receiver captures the strong signal from the main lobe (referred to as a strong satellite), the acquisition efficiency and accuracy are much higher than when capturing the weak signal from a side lobe (referred to as a weak satellite). Thus, a rapid signal recapture algorithm using a strong satellite to assist weak satellites is proposed. Firstly, the position error pattern of the high orbit receiver during the loss-of-lock period is analyzed and the range of the pseudo-range estimation error from the receiver to the weak satellite is derived. Then, assuming that the receiver has already captured a main lobe signal, the distance constraint between the receiver and the captured satellite is used to reduce the receiver's position uncertainty, thereby narrowing the range of the pseudo-range estimation error for the satellite to be captured and reducing the number of code phase search units. Theoretical analysis and simulation results show that, with the assistance of a strong satellite, the code phase search range for capturing a weak satellite is reduced by more than 50% on average, and the reduction is inversely proportional to the sine value of the angle between the line-of-sight vectors of the strong and weak satellites. Furthermore, the higher the receiver's orbit, the smaller the average angle between the line-of-sight vectors of the strong and weak satellites, and the better the compression effect on the weak satellite's code phase search range. This method can significantly improve the efficiency of signal re-acquisition for high orbit receivers and enhance their autonomous navigation capabilities. Related Articles | Metrics

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Simulation and analysis of satellite-based radio signal shielding LIU Wei, HE Quan, RAO Jianbing 2026, 46 (1):  178-184.  doi: 10.16708/j.cnki.1000-758X.2026.0017 Abstract ( 49 )   PDF (6204KB) ( 23 )   Save In the process of the diversified functions and complex geometric of spacecraft, aiming at the problems of shielding analysis and design optimization among components, analyze and evaluate the potential solutions. Through coordinate rotation, the shielding geometry is projected from the three-dimensional space onto the two-dimensional plane, and the problem is simplified to the judgment of the geometric relationship between points and triangles. Based on the panel method, the judging the front and back positions of geometry and the necessary conditions of point in triangles are introduced for double filter, which greatly reduces the number of calculation tasks and improves the efficiency of shielding analysis. A simplified three-dimensional model of the Starlink Gen2 is constructed, and simulation analysis is carried out. Statistics show that the twice screening can reduce the amount of calculation by about 95% on average. The shielding heatmap of the solar wings corresponding to different position antenna are provided. Verify the correctness and effectiveness of the projection conversion plus two-level screening method, break through the shortcomings of commercial software such as STK, such as single output information and uncontrollable process, and it can better support the optimization work of the layout design of spacecraft components. Related Articles | Metrics

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Region-aware VAE quantization with information hiding for satellite image compression ZHANG Lizhe, ZHOU Quan, XIAO Huachao, ZHENG Xiaosong, HUYAN Lang 2026, 46 (1):  185-197.  doi: 10.16708/j.cnki.1000-758X.2026.0018 Abstract ( 34 )   PDF (26797KB) ( 14 )   Save To address detail loss in complex feature regions of neural network-based satellite image compression, a novel algorithm integrating region-aware mechanisms with variational autoencoder (VAE) quantization was proposed. The method prioritized key-region quality while maintaining overall compression ratios and enabling covert data embedding. Firstly, critical regions were identified by YOLO, then mapped images to latent space via ResNet VAE. During quantization, key-region features were hidden within background bitstreams before entropy encoding. Differential compression strategies were applied: aggressive compression for backgrounds and mild compression for key regions. Experiments demonstrated superior performance over conventional and deep learning benchmarks. At 25×compression ratio, the method achieved 35.27dB PSNR (full image), surpassing state-of-the-art techniques by 3.5dB. Key regions attained 41.15dB PSNR and 0.992 SSIM, a 7.55dB improvement over baseline algorithms, effectively preserving fine details. The algorithm enhances compression fidelity without increasing bitstreams, while enabling secure data hiding. It proves particularly effective for high-resolution satellite imagery and sensitive area protection, offering a balanced solution for efficient storage and secure transmission. Related Articles | Metrics

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Optical imaging chain modeling for the lunar south pole based on time-delay integration camera LI Menghao, CHEN Yueting, FU Ruimin, LI Qi, YANG Jukui, JIA Fujuan, XU Zhihai 2026, 46 (1):  198-209.  doi: 10.16708/j.cnki.1000-758X.2026.0004 Abstract ( 58 )   PDF (9363KB) ( 25 )   Save The lunar south pole has become a focal point for the next phase of lunar exploration, and optical remote sensing is a critical tool for acquiring scientific data about the lunar south pole. Due to the complex lighting conditions at the lunar poles, time-delay integration (TDI) cameras, capable of dynamically adjusting integration levels, are essential optical payloads for future lunar polar missions. This study utilized a backward path tracing method, incorporating parameters of the TDI camera, orbiter trajectory, the three-dimensional structure of the lunar south pole, and the lighting conditions near the poles, to construct a comprehensive optical remote sensing imaging model which simulates imaging results under varying parameters. The proposed simulation method was applicable to regions with direct illumination and permanently shadowed regions, which were illuminated only by secondary scattering light. A comparison with real images from the linear array scanning camera onboard the Lunar Reconnaissance Orbiter (LRO) shows that the average relative error for simulated images of directly illuminated regions is within 10%. The results also validate the high-resolution imaging capability of the TFS camera in permanently shadowed regions. This study provides a feasible simulation framework for future optical remote sensing missions to the lunar south pole,offering valuable guidance for researchers in selecting appropriate parameters for practical engineering applications.  Related Articles | Metrics