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Computing N-dimensional polytrope via power series Open Astron. (IF 0.7) Pub Date : 2024-04-12 Mohamed I. Nouh, Mahmoud Taha, Ahmed Ahmed Ibrahim, Mohamed Abdel-Sabour
Polytropic equations (Lane–Emden [LE] equations) are valuable because they offer a simple explanation for a star’s interior structure, interstellar matter, molecular clouds, and even spiral arms that can be calculated and used to estimate various physical parameters. Many analytical and numerical methods are used to solve the polytropic LE equation. The series expansion method played an essential role
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Observations of comet C/1652 Y1 recorded in Korean histories Open Astron. (IF 0.7) Pub Date : 2024-04-02 Uhn Mee Bahk, Ki-Won Lee, Byeong-Hee Mihn, Sang Hyuk Kim
We report the Korean records for comet C/1652 Y1, which have not been introduced in previous studies on historical comets. According to Korean historical documents, this comet, described as bai xing (white star, in literal) or ke xing (guest star, in literal), was observed with the naked eye for 22 days from December 19, 1652 to January 9, 1653. In this study, we first cross-checked the records of
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Multidimensional visualization analysis based on large-scale GNSS data Open Astron. (IF 0.7) Pub Date : 2024-03-19 Jingyan Wang, Ronghui Wang, Zhenyong Bo, Hengnian Li, Chong Wang, Yanan Fang
With the deployment of global navigation systems such as GPS, GLONASS, GALILEO, and BeiDou, and the construction of the global observation network, global navigation satellite system (GNSS) data have greatly expanded. Traditional relational databases and file systems can no longer efficiently store and process GNSS data. In addition, multidimensional, in-depth visual analysis methods for such data
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Application of SDN-IP hybrid network multicast architecture in Commercial Aerospace Data Center Open Astron. (IF 0.7) Pub Date : 2024-03-16 Chen Gang, Chen Guangyu, Tong Xin, Ren Qiaoyan, Kuang Dongmei
The increasing amount of massive data generated by commercial spacecraft in orbit puts forward higher and higher requirements for the stability, reliability, and computing power of computer systems for commercial aerospace data center. Data center computer systems are gradually transforming from X86 architecture and IP network model to a platform model with cloud computing and software-defined network
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Retrograde infall of the intergalactic gas onto S-galaxy and activity of galactic nuclei Open Astron. (IF 0.7) Pub Date : 2024-03-08 Sergey S. Khrapov, Alexander V. Khoperskov
We present the results of numerical simulations focused on the accretion of intergalactic gas onto a gas-rich S-type disc galaxy. Our investigation explores the conditions favouring the emergence of counterrotating stellar and gaseous components within the galaxy, leading to the inflow of gas towards the central kiloparsec of the galaxy. Notably, we find that the most substantial reservoir of gas,
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A generalized super-twisting algorithm-based adaptive fixed-time controller for spacecraft pose tracking Open Astron. (IF 0.7) Pub Date : 2024-01-05 Kejie Gong, Yong Wang, Yurui Duan, Yafei Mei, Yu Jiang, Da Luo
A generalized super-twisting second-order sliding mode adaptive fixed-time control law, which is used for spacecraft pose tracking in the presence of internal and external uncertainties, is proposed. Lie group SE(3) (for special Euclidean group), which is the configuration space for rigid body motion, is used for modeling the six-degrees-of-freedom dynamics of spacecraft. A fixed-time sliding mode
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A holistic study of the systems V0487 Lac, V0566 Hya, and V0666 Lac Open Astron. (IF 0.7) Pub Date : 2023-09-26 Moqbil S. Alenazi, Magdy M. Elkhateeb
A comprehensive photometric study and evolutionary state for the systems V0487 Lac, V0566 Hya, and V0666 Lac were carried out by means of their first photometric observations. New times of minima were estimated from the observed light curves, and first (O–C) curves were established for all systems. The radiative treatment was carried out using a Windows interface version of the Wilson and Devinney
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Light curve analysis of main belt asteroids 4747, 5255, 11411, 15433, 17866 Open Astron. (IF 0.7) Pub Date : 2023-08-26 Ilgmars Eglitis, Nagainis Kristers
The main belt asteroids 4747, 5255, 11411, 15433, and 17866 were studied at the Baldone Astrophysical Observatory in the time span range 2018–2022. The obtained light curve data together with published Minor Planet Center data are analyzed with Fourier series, Lomb-Scargle periodogram, and phase dispersion minimization methods. A plan of analysis is given. The results computed from different observatories’
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The history of the Cosmos: Implications for the Hubble tension Open Astron. (IF 0.7) Pub Date : 2023-08-02 Riccardo C. Storti
In 2007, Storti predicted that the value of the cosmic microwave background radiation (CMBR) temperature may be improved: from the particle data group (PDG) value of [T 0 = 2.725 ± 0.001 K] to [T 0 = 2.7254 K]. In 2011, the PDG revised their value of CMBR to [T 0 = 2.7255 ± 0.006 K]. In 2008, Storti predicted a ΛCDM Hubble constant of [H 0 = 67.0843 km/s/Mpc]. In the same year, the PDG published their
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An ion beam system for calibration of space low-energy ion detectors Open Astron. (IF 0.7) Pub Date : 2023-06-30 Shi Guifen, Li Yiren, Miao Bin, Liu Kai, Hao Xinjun, Pan Zonghao, Guan Meng
Low-energy ion detection in space is one of the most important interests of space exploration. An accurate calibration of this type of instrument is necessary to ensure the effectiveness and scientificness of the obtained data. And the ion source is the most critical equipment in a calibration facility. In this study, an ion beam system based on Kaufman ion source is designed, which can meet the ground
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Investigation of the halo effect in the evolution of a nonstationary disk of spiral galaxies Open Astron. (IF 0.7) Pub Date : 2023-06-26 Kamola Alimdjanovna Mannapova, Karamat Taxirovna Mirtadjieva
In this article, we consider the problem of the evolution of the disk subsystem of galaxies, taking into account their halos. The global structure of the disk of galaxies strongly depends on the mass and shape of the halo. To this end, we have studied the evolution of nonradial oscillations of a nonstationary disk surrounded by a passive ellipsoidal halo with a uniform density. A system of equations
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Necessary condition for temporary asteroid capture Open Astron. (IF 0.7) Pub Date : 2023-06-14 Changchun Bao, Zhijie Li, Xianyu Wang
Asteroid capture holds great significance in understanding the origins of asteroids, the source of life, and the exploration of planetary mineral resources. To ensure the success of a mission aimed at capturing asteroids, it is crucial to choose asteroids that can be naturally captured by Earth. This article focuses on the orbital characteristics of temporarily captured asteroids. Through a statistical
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Ka/C dual frequency ranging system for ocean altimetry satellite and analysis of ionospheric error Open Astron. (IF 0.7) Pub Date : 2023-05-10 Nan Li, Zhenhe Zhai, Jian Ma, Bin Guan, Wenhui Cui, Duan Li
In view of the future development trend of ocean altimetry satellites, the design idea of Ka/C dual frequency combination system is proposed, that is, the mode of using an altimeter antenna to contain Ka and C frequencies (35.7 and 5.3 GHz, respectively) for combined ranging. First, the random error model of altimeter measuring the distance from the altimeter phase center to the sea surface is given
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Late-time dark energy and Hubble tension Open Astron. (IF 0.7) Pub Date : 2023-05-10 Dragana Pilipović
We extend Einstein’s theory of general relativity by introducing stochastic elements in addition to the usual fields and apply it to explore late-time redshift. The stochastic perturbation of spacetime enforces an effective minimum length (ML) to give us a cosmological constant naturally derived from the diffusive nature of spacetime and a redshift driven by both the geometry of spacetime as well as
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Dust and gas in star-forming complexes in NGC 3351, NGC 5055, and NGC 5457 Open Astron. (IF 0.7) Pub Date : 2023-04-25 Ksenia Ildarovna Smirnova, Dmitri Siegfriedovich Wiebe
We present a study of the interstellar medium parameters in star-forming complexes (SFCs) in NGC 3351, NGC 5055, and NGC 5457 galaxies. This study concludes our previous investigations of gas and dust in a number of spiral galaxies. The data for the three galaxies confirm the following. There is a tight correlation between near-infrared and far-infrared luminosities of the extragalactic SFCs. Emission
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Radiation environment and effect detection based on global navigation constellation Open Astron. (IF 0.7) Pub Date : 2023-04-21 Lin Quan, Dongya Wang, Qingxiang Zhang, Shenyi Zhang, Ling Li, Shuai Wang, Tao Jing, Yinan Meng, Yenan Liu, Chao Tian
Combining the anomalies and environmental monitoring data of the early stage Beidou satellites, the space radiation environment spatial/temporal distribution and space radiation effect risk characteristics are analyzed, and the dynamic characteristics of space environmental factors, such as hot plasma, high-energy electron and solar proton are summarized. The systematic joint monitoring for surface
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Monitor of the single event upsets and linear energy transfer of space radiation on the Beidou navigation satellites Open Astron. (IF 0.7) Pub Date : 2023-04-15 Binquan Zhang, Shenyi Zhang, Guohong Shen, Changsheng Tuo, Xin Zhang, Huanxin Zhang, Lin Quan, Chao Tian, Donghui Hou, Ping Zhou, Wentao Ji
The single event effect caused by space heavy ion radiation is one of the important factors affecting the safety and operation of spacecraft on orbit. In the research and evaluation of the frequency, spatial distribution and time characteristics of single event effects, linear energy transfer (LET) spectra of space radiation play an important role. On the Beidou navigation M15 and M16 satellites, a
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Surface charging and dose monitor on geosynchronous orbit satellite Open Astron. (IF 0.7) Pub Date : 2023-04-02 Yuzhan Zheng, Qingxiang Zhang, Hongwen Xiang, Shuai Yao, Yi Zheng, Lin Quan
Based on the typical dielectric materials and devices of satellite, a surface charging and dose monitor (SCAD) was developed to measure the surface charging voltage, current, and dose under different shielding depths. The SCAD has been successfully launched into orbit on June 23, 2020. The measurement results on orbit show that the SCAD works normally, and the data of SCAD are reasonable. The results
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Design and validation of a space plasma environment detector for BeiDou navigation satellite Open Astron. (IF 0.7) Pub Date : 2023-03-31 Zhenyu Tang, Qiongying Ren, Hao Li, Yuchuan Peng, Zhong Peng, Qinghai Liu, Junfeng Wang, Yenan Liu, Lili Ge, Da Wu, Hua Zhao
Most of the satellites of the BeiDou navigation system work in geostationary orbit (GEO) and medium earth orbit (MEO), where the space plasma environment can make a severe impact on spacecraft. To measure the parameters of the plasma environment in GEO and MEO orbital space and to improve the design of the environmental adaptability of the satellites based on in situ probe data, a 2π-solid-angle omnidirectional
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A new version of the binary star database BDB: Challenges and directions Open Astron. (IF 0.7) Pub Date : 2023-03-10 Pavel Kaygorodov, Nikolay Skvortsov, Dana Kovaleva, Oleg Malkov
In accordance with the principles of open science, the results of the research should remain available for further investigations and practical interaction with them in the research community. Such results include collected initial and obtained data, specifications and implementations of methods applicable to them including data integration rules, and other possible resources. At the same time, the
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Far-IR emission from bright high-redshift quasars Open Astron. (IF 0.7) Pub Date : 2023-03-03 Evgenii O. Vasiliev, Yuri A. Shchekinov, Biman B. Nath
The majority of quasars detected at high redshifts ( z ≳ 6 z\gtrsim 6 ) strongly emit ultraviolet radiation with absolute magnitudes at rest-frame M 1450 Å , A B ∼ − ( 29 – 27 ) {M}_{1450\mathring{\rm A} ,AB}\hspace{0.33em} \sim \hspace{0.33em}-\left(29\hspace{0.1em}\text{–}\hspace{0.1em}27) . Some of them have high luminosities in [CII] 158 μ m 158\hspace{0.33em}{\rm{\mu }}{\rm{m}} line and in far-infrared
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Braking and attitude control of lunar lander in active descent stage Open Astron. (IF 0.7) Pub Date : 2023-02-28 Leru Luo, Changchun Bao
China officially launched the lunar exploration project, named “Chang’e Project,” in 2004. Then, in 2013, Chang’e-3 completed the soft landing on the lunar surface, starting a series of studies on the soft landing of spacecraft. This study aims to optimize the dynamic flight guidance and attitude control of the lunar landing module represented by Chang’e-3 in the soft landing stage. After analyzing
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Radiation dosimeter and charge detector onboard BeiDou navigation satellites in MEO Open Astron. (IF 0.7) Pub Date : 2023-02-24 Ying Sun, Shenyi Zhang, Guohong Shen, Lin Quan, Zheng Chang, Chao Tian, Tao Jing, Huanxin Zhang, Jianjing Ding, Bin Yuan, Binquan Zhang
The orbit of BeiDou satellite system is a very ideal space environment monitoring area. The radiation dosimeters are present on this series of navigation satellites, and they are respectively installed in the x, y and z positions. A charge detector installed in the satellite cabin is used for monitoring satellite deep charging potential. Radiation dosimeters select the 100 nm P-channel metal oxide
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High-energy proton detector based on semiconductor telescope Open Astron. (IF 0.7) Pub Date : 2023-02-22 GuoHong Shen, ShenYi Zhang, Lin Quan, Chao Tian, HuanXin Zhang, Zheng Chang, XianGuo Zhang, Xin Zhang, Ying Sun, Ze Yang, Yueqiang Sun
Space radiation particles will cause a variety of radiation effects on orbiting satellites, such as single event effects, total ionizing dose, displacement damage, etc. In response to these space radiation effects, BeiDou Navigation satellites M15/M16 operating in medium earth orbit (MEO) developed the first integrated monitor for high-energy proton and particle radiation effects, based on space particle
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Clay minerals and other hydrous alteration products in the Kaba meteorite: Review of the literature and new XRD investigations Open Astron. (IF 0.7) Pub Date : 2023-02-21 István Viczián, Ferenc Kristály
The present study is a review of publications regarding special aspects of the mineralogy of the Kaba meteorite, clay minerals, hydrous phases, and organic matter. In Section 1, the history of fall and finding of the meteorite and the first classical mineralogical description in the Year 1961 are mentioned. The most frequent alteration product of primary silicates and the glassy matrix is Fe-bearing
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Magnetic fields with random initial conditions in discs with Kepler rotation curve Open Astron. (IF 0.7) Pub Date : 2023-02-18 Denis A. Grachev, Evgeny A. Mikhailov, Ekaterina N. Zhikhareva
Magnetic fields of various astrophysical objects are described using the dynamo mechanism. Corresponding equations in the three-dimensional case are quite difficult to be solved. So, the two-dimensional models can be useful for such problems. For galactic and accretion discs, it is convenient to use the no- z z approximation. The initial conditions for the magnetic field have a special interest. It
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Crossmatching of high-proper motion L, T, and Y brown dwarfs with large photometric surveys Open Astron. (IF 0.7) Pub Date : 2023-02-16 Aleksandra S. Avdeeva, Sergey V. Karpov, Oleg Yu. Malkov
L, T, and Y brown dwarf (BD) exploration is a topical issue. First, the transition boundary between planets and BDs is not fully understood yet. Second, there is a phenomenon called the L/T-transition. The observed properties of cooler BDs differ significantly from the less cool ones, namely, colors of BDs shift much bluer and, simultaneously, dwarfs become brighter with a decrease in temperature.
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A low-energy ion spectrometer with large field of view and wide energy range onboard a Chinese GEO satellite Open Astron. (IF 0.7) Pub Date : 2023-02-14 Xu Shan, Bin Miao, Zhe Cao, Zhenyu Sun, Yiren Li, Kai Liu, Sanbiao Qu, Xingyu Guo, Zhenpeng Su, Chenglong Shen, Zonghao Pan, Xin Li, Xinjun Hao, Xiaoping Yang, Chao Tian, Yu Jiang, Shubin Liu, Qi An, Xiangjun Chen, Yuming Wang
A low-energy ion spectrometer (LEIS), onboard a Chinese navigation satellite in geosynchronous orbit, is one of the primary instruments for plasma detection. The LEIS is implemented by combining a top-hat electrostatic analyzer with a pair of angular scanning deflectors, which enables us to achieve in situ measurement of energetic ions in three-dimensional (3D) space with a large field of view of 360°
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An outlier detection method with CNN for BeiDou MEO moderate-energy electron data Open Astron. (IF 0.7) Pub Date : 2023-02-10 Tian Chao, Cui Ruifei, Zhang Riwei, Xu Peikang, Chen Libo, Shang Jie, Quan Lin, Wan Yujun, Hu Sihui, Yue Fulu, Su Xing
BeiDou Medium Earth Orbit moderate-energy electron detection data play an important role in space environment effect analysis including satellite anomaly diagnosis, satellite risk estimation, etc. However, the data contain outliers which cause obstacle for the subsequent usage significantly. To solve this problem, we propose an outlier detection method based on convolutional neural networks (CNNs)
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Medium and high energy electron detectors onboard BeiDou navigation satellite in MEO Open Astron. (IF 0.7) Pub Date : 2023-02-02 Huanxin Zhang, Guohong Shen, Shenyi Zhang, Lin Quan, Chao Tian, Xiangtang Cui, Changsheng Tuo, Donghui Hou, Ying Sun, Lihui Cheng, Ping Zhou, Wentao Ji
This work introduces the instruments’ design of multi-directional medium-energy electron detector (energy range: 30–770 keV) and high-energy electron detector (energy range: 400 keV to 5.8 MeV) deployed on one of the BeiDou navigation satellites in medium earth orbit. Through the electromagnetic compatibility design, the problem of the detector signal being susceptible to electromagnetic interference
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Deep learning applications for stellar parameter determination: II-application to the observed spectra of AFGK stars Open Astron. (IF 0.7) Pub Date : 2023-01-23 Marwan Gebran, Frederic Paletou, Ian Bentley, Rose Brienza, Kathleen Connick
In this follow-up article, we investigate the use of convolutional neural network for deriving stellar parameters from observed spectra. Using hyperparameters determined previously, we have constructed a Neural Network architecture suitable for the derivation of T eff {T}_{{\rm{eff}}} , log g \log g , [ M / H ] \left[M\hspace{0.1em}\text{/}\hspace{0.1em}H] , and v e sin i {v}_{e}\sin i . The network
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Cooperative capture trajectory optimization of multi-space robots using an improved multi-objective fruit fly algorithm Open Astron. (IF 0.7) Pub Date : 2022-12-21 Yong Wang, Jing Cao, Nan Ye, Shouming Sun, Junfeng Li, Zhenyong Bo
Considering that some tasks will require the consistency of the position and attitude of the end-effector, multi-space-robot cooperative capture also needs to consider the synchronization of the two capture arms. Taking the dual-space robots as example, the trajectory planning problem before cooperative capture is focused. First, a drive-transform method based on trapezoidal velocity interpolation
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Access once encountered TT&C mode based on space–air–ground integration network Open Astron. (IF 0.7) Pub Date : 2022-11-22 Chao Li, Peijie Liu, Shiyuan Fu, Yiwen Jiao
In order to deal with the shortage of spacecraft telemetry, tracking, and command (TT&C) resources and the high complexity of planning and scheduling in the future, based on the current situation of the TT&C network in China, the construction requirements of space–ground integration TT&C network are put forward, and the basic framework is constructed. Referring to the random access mechanism of ground
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Integrated design of ranging and DOR signal for China's deep space navigation Open Astron. (IF 0.7) Pub Date : 2022-11-16 Dezhen Xu, Lei Huang, Shaowu Chen
An integrated ranging and differential one-way range (DOR) signal design is implemented. The design utilizes the regenerative pseudo-noise ranging scheme and one pair of dedicated DOR tones for the deep space United X Band system. To demonstrate its effectiveness, it was applied to China’s Tianwen-1 orbiter and compared with the classic and normal designs. Using the link budget and error analysis methods
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Analysis of the equilibrium points and orbits stability for the asteroid 93 Minerva Open Astron. (IF 0.7) Pub Date : 2022-11-16 Hu Liu, Yu Jiang, Anqi Lang, Yajie Wang, Xiaoduan Zou, Jinsong Ping, Yutong Chang, Yongzhang Yang, Chen Zheng, Yi Lian, Jianfeng Cao
In this article, we study the orbital dynamics with the gravitational potential of the asteroid 93 Minerva using an irregular shape model from observations. We calculate its physical size, physical mass, surface height, and zero-velocity surface. Meanwhile, we recognize that there are five equilibrium points around Minerva, four of which are external, and one is internal. Two of the external equilibrium
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Close-range leader–follower flight control technology for near-circular low-orbit satellites Open Astron. (IF 0.7) Pub Date : 2022-10-26 Yuan Yang, Hengnian Li, Yikang Yang, Chongyuan Hou, Kaijian Zhu
Based on the characteristics of near-circular orbits and close-range leader–follower flights, the relative dynamics equations of the eccentricity/inclination ( e/i ) vector method are introduced herein. Additionally, the constraint terms in the design of the leader–follower flight formation are found to satisfy the conditions of the line-of-sight angle and inter-satellite distance. The control box
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High-speed inter-satellite link construction technology for navigation constellation oriented to engineering practice Open Astron. (IF 0.7) Pub Date : 2022-10-14 Canyou Liu, Feng Zhang, Hao Ma, Shuang Chen, Xin Wang, Xiusong Ye
This article presents a study on the design of high-speed inter-satellite links for the global navigation satellite system, which consists of 24 middle earth orbit, 3 inclined geosynchronous orbit, 3 geostationary orbit satellites, and 4 typical ground stations based on the laser link of slowly varying continuous system and high-speed Ka link. Pre-allocation of node connections in inter-satellite link
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On-board BDS dynamic filtering ballistic determination and precision evaluation Open Astron. (IF 0.7) Pub Date : 2022-10-06 Shu-Qiang Zhao, Jia-Yu Chang
BeiDou navigation satellite system (BDS) receivers on-board cannot give real-time positioning precision in tracking missile and carrier rocket. In this article, the dynamic filtered optimal estimation theory is applied to the highly dynamic on-board BDS ballistic parameter solution, an optimally constrained geometric dilution precision (GDOP) constellation selection strategy is proposed, a mathematical
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Wide binary stars with non-coeval components Open Astron. (IF 0.7) Pub Date : 2022-09-27 Oleg Malkov, Alexey Kniazev
We have the estimated masses of components of visual binaries from their spectral classification. We have selected pairs in which the less massive component looks more evolved. Spectral observations of some of these pairs were made, and at least one pair, HD 156331, was confirmed to have components of different ages. Since mass exchange is excluded in wide binaries, it means that HD 156331 can be formed
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Research on fault detection and principal component analysis for spacecraft feature extraction based on kernel methods Open Astron. (IF 0.7) Pub Date : 2022-09-27 Na Fu, Guanghua Zhang, Keqiang Xia, Kun Qu, Guan Wu, Minzhang Han, Junru Duan
Satellite anomaly is a process of evolution. Detecting this evolution and the underlying feature changes is critical to satellite health prediction, fault early warning, and response. Analyzing the correlation between telemetry parameters is more convincing than detecting single-point anomalies. In this article, principal component analysis method was adopted to downscale the multivariate probability
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Optimization of satellite resource scheduling under regional target coverage conditions Open Astron. (IF 0.7) Pub Date : 2022-09-21 Kaixi Liu, Yajie Wang, Baohui Zhang, Hu Liu, Xu Wang, Bin Wei
This study presented a mathematical description of an arbitrary shape area, and after analyzing the characteristics of the near-polar orbital co-ground trajectory constellation that satisfies the revisit interval constraint, an optimization model of the orbital parameters design of reference satellites in regional coverage constellations was constructed. Then based on the designed area covering the
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Angular acceleration compensation guidance law for passive homing missiles Open Astron. (IF 0.7) Pub Date : 2022-09-21 Jixin Li, Xiaogeng Liang, Keqiang Xia, Yilin You
Proportional navigation guidance law (PNG) is widely used for passive homing missiles. But PNG often suffers from inaccurate tracking of target or even failure when the target is maneuvering quickly or releasing artificial decoys. In order to solve this problem, the angular acceleration compensation guidance law (AACG) is constructed by using line of sight (LOS) angular velocity and LOS angular acceleration
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Research progress on the effects of microgravity and space radiation on astronauts’ health and nursing measures Open Astron. (IF 0.7) Pub Date : 2022-09-03 Xinhua Cao
With the development of human space technology, more and more astronauts fly into space. With the rapid development of commercial aerospace, more ordinary people will go to space for sightseeing. However, it should not be ignored that microgravity, space radiation, relative geometry, and orbit of space stations have various effects on the health of astronauts. In recent years, scholars in various countries
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A micro/nano joint satellite design of high maneuverability for space debris removal Open Astron. (IF 0.7) Pub Date : 2022-09-03 Yuan An, Dan Chen, Nengjian Tai, Jun Zhu, Ge Zhang, Qi Zhang
Ever-increasing space debris poses a great threat to spacecraft safety; its removal debuts as an innovative technology and will be in demand in the future. This article proposes a design for micro/nano joint satellites composed of four micro/nanosatellites with high maneuverability to clear space debris. The design incorporates two operating modes with typical applications, and the joint satellite
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Performance of dual one-way measurements and precise orbit determination for BDS via inter-satellite link Open Astron. (IF 0.7) Pub Date : 2022-08-29 Jun Zhu, Hengnian Li, Jie Li, Rengui Ruan, Min Zhai
The continuous full operation of the constellation of BeiDou navigation satellite system (BDS) provides favorable conditions for the performance evaluation of the BDS inter-satellite links (ISLs). The primary features of ISLs that affect the precision of precise orbit determination (POD) and time synchronization include (i) the spatiotemporal coverage or continuity of observations; (ii) the observational
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High-altitude satellites range scheduling for urgent request utilizing reinforcement learning Open Astron. (IF 0.7) Pub Date : 2022-08-09 Bo Ren, Zhicheng Zhu, Fan Yang, Tao Wu, Hui Yuan
High-altitude satellites are visible to more ground station antennas for longer periods of time, its requests often specify an antenna set and optional service windows, consequently leaving huge scheduling search space. The exploitation of reinforcement learning techniques provides a novel approach to the problem of high-altitude orbit satellite range scheduling. Upper sliding bound of request pass
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End-of-discharge prediction for satellite lithium-ion battery based on evidential reasoning rule Open Astron. (IF 0.7) Pub Date : 2022-07-29 Dao Zhao, Zhijie Zhou, Peng Zhang, Yijun Zhang, Haibin Qin, Shan Gao
To ensure the safety of the power supply for an in-orbit satellite, it is of great significance to accurately predict the end-of-discharge time of lithium-ion batteries for making a reasonable flight plan. Constrained by development time and experimental environment, it is usually difficult to obtain many full discharge voltage curves of satellite batteries from ground experiments as historical data
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Observational data and orbits of the comets discovered at the Vilnius Observatory in 1980–2006 and the case of the comet 322P Open Astron. (IF 0.7) Pub Date : 2022-07-02 Ireneusz Włodarczyk, Kazimieras Černis
This article is devoted to the discovery of comets at the Vilnius Observatory together with the orbital analysis of dynamically interesting comets, namely 322P. We studied the orbital evolution of comet 322P with and without non-gravitational effects. It turned out that many of the comet’s orbital clones go into and out of retrograde orbits, sometimes repeatedly. The reason for such dramatic changes
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Improvement of orbit prediction accuracy using extreme gradient boosting and principal component analysis Open Astron. (IF 0.7) Pub Date : 2022-06-23 Min Zhai, Zongbo Huyan, Yuanyuan Hu, Yu Jiang, Hengnian Li
High-accuracy orbit prediction plays a crucial role in several aerospace applications, such as satellite navigation, orbital maneuver, space situational awareness, etc. The conventional methods of orbit prediction are usually based on dynamic models with clear mathematical expressions. However, coefficients of perturbation forces and relevant features of satellites are approximate values, which induces
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Application of cloud computing key technology in aerospace TT&C Open Astron. (IF 0.7) Pub Date : 2022-06-09 Gang Chen, Xin Tong, WeiBing Du, Jing Zhao, HanYong Zhang
The basic concepts, technical implementation, and application scenarios of computer simulation, virtualization, and cloud computing are intertwined and each has its characteristics. In this article, the basic concepts, necessity, feasibility, and core difficulties of computer simulation, virtualization, and cloud computing are analyzed. Also, the application prospects of the three technologies are
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Research on real-time reachability evaluation for reentry vehicles based on fuzzy learning Open Astron. (IF 0.7) Pub Date : 2022-06-07 Hong Ma, Ke Xu, Shouming Sun, Wei Zhang, Tao Xi
Accurate and rapid prediction of reentry trajectory and landing point is the basis to ensure the reentry vehicle recovery and rescue, but it has high requirements for the continuity and stability of real-time monitoring and positioning data and the fidelity of the reentry prediction model. In order to solve the above contradiction, based on the theory of relative entropy and closeness in fuzzy learning
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The evolution of time-dependent Λ and G in multi-fluid Bianchi type-I cosmological models Open Astron. (IF 0.7) Pub Date : 2022-06-07 Alnadhief H. A. Alfedeel, Amare Abebe
In this work, cosmological solutions based on the time-dependent cosmological ( Λ \Lambda ) and Newtonian ( G G ) running “constants” in the Bianchi type-I spacetime are investigated vis-à-vis known cosmological data. The observationally known values of Ω m , Ω r {\Omega }_{{\rm{m}}},{\Omega }_{{\rm{r}}} and Ω Λ {\Omega }_{\Lambda } have been used to solve the Einstein field equations for the model
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The specifics of pulsar radio emission Open Astron. (IF 0.7) Pub Date : 2022-05-23 Boris Ya. Losovsky
A characteristic property of pulsars is pulsed periodic radio emission, which has a high stability of periods. Despite the high stability of the emission periods of pulsars, monitoring the time of arrival of pulses (timing) shows the presence of different types of irregularities: variations of residual deviations, changes in the shape of the pulse, switching on and off of radio emission, and rotation
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Explaining the cuspy dark matter halos by the Landau–Ginzburg theory Open Astron. (IF 0.7) Pub Date : 2022-05-20 Dong-Biao Kang, Tong-Jie Zhang
The equilibrium cold dark matter halos show the almost universal inner r − 1 {r}^{-1} cusps, whose physical origin is still not completely clear. This work tries to further clarify this problem by the Landau–Ginzburg (LG) theory, which is often used to study the long-range correlation of the fluctuations in the critical phenomenon, and we will first introduce it in detail. The order parameter in this
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Influence of the magnetic field on the formation of protostellar disks Open Astron. (IF 0.7) Pub Date : 2022-04-25 Natalya S. Kargaltseva, Sergey A. Khaibrakhmanov, Alexander E. Dudorov, Sergey N. Zamozdra, Andrey G. Zhilkin
We numerically model the collapse of magnetic rotating protostellar clouds with mass of 10 M ⊙ {M}_{\odot } . The simulations are carried out with the help of 2D MHD code Enlil. The structure of the cloud at the isothermal stage of the collapse is investigated for the cases of weak, moderate, and strong initial magnetic field. Simulations reveal the universal hierarchical structure of collapsing protostellar
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Peculiarities of radio emission from new pulsars at 111 MHz Open Astron. (IF 0.7) Pub Date : 2022-04-18 Daria Teplykh, Valery Malofeev, Oleg Malov, Sergey Tyul’bashev
The analysis of radio emission of three new pulsars discovered at the Pushchino Radio Astronomy Observatory is presented. The detailed observations were carried out at a frequency of 111 MHz using the large phase array and the standard digital receiver with a total bandwidth of 2.245 MHz and a time resolution of 2.46 or 5.12 ms. All pulsars exhibit features of their radiation, the subpulse drift is
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Bubbles and OB associations Open Astron. (IF 0.7) Pub Date : 2022-04-13 Sergey A. Drozdov, Evgenii O. Vasiliev, Marina V. Ryabova, Yuri A. Shchekinov, Biman B. Nath
Supernovae explosions (SNe) in a stratified interstellar disc can create large scale structures and outflows perpendicular to the disc. Their morphology and emission characteristics depend on interrelations between the number of exploded SNe, the ISM vertical scale height, the height above the ISM disc at which SNe are located, and the mid-plane density of ambient gas. When observed such out-of-plane
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New triple-mode high-amplitude Delta Scuti variables Open Astron. (IF 0.7) Pub Date : 2022-04-08 Anton V. Khruslov
I present a detection of four new triple-mode high-amplitude Delta Scuti variables, pulsating in the fundamental, first, and second overtone modes. This is a new addition to the ten known cases in the Galaxy. I used the data of ASAS-SN and analyzed them using the WinEfk code by V. P. Goranskij. Light elements and parameters of the light curves were obtained.
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Photometry and kinematics of extragalactic star-forming complexes Open Astron. (IF 0.7) Pub Date : 2022-04-04 Aleksey Kuzin, Danil Lisitsin
We investigate spectral and photometric properties of extragalactic star-forming complexes (SFCs). The SFCs were selected in 17 nearby galaxies of a spiral or irregular type, having inclinations less than 45° and distances less than 15 Mpc. To identify SFCs, we developed a method based on matching sources of emission at 160 μ m 160\hspace{0.33em}{\rm{\mu }}{\rm{m}} (cold dust) and 8 μ m 8\hspace{0
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Checking the possibility of determining the relative orbits of stars rotating around the center body of the Galaxy Open Astron. (IF 0.7) Pub Date : 2022-03-28 Natalia A. Shakht, Igor S. Izmailov, Denis L. Gorshanov
The results of observations of selected stars orbiting the central body of our Galaxy, which, according to the latest data, has a mass of about 4 million of solar mass, are considered. Using the methods of observation and processing of binary stars used at the Pulkovo Observatory and the published exact relative positions of the star-central body obtained with the Keck and VLT telescopes, we checked