Bin Liu, Hengnian Li, Xiyun Hou, Jie Yang, Zongbo Huyan
With more and more activities in cislunar space and deep space, a navigation system that can provide autonomous navigation service for cislunar or even deep space missions has become an urgent need. This article proposes a new type of navigation constellation which is placed on two kinds of special orbits, namely the dynamical substitutes around the triangular libration points and the distant retrograde orbits (DROs). Both types of orbits have the same characteristics of long-term stability under the full force model, so no orbit control is needed and it can operate autonomously without ground support. First, using inter-satellite range data, the autonomous orbit determination between navigation satellites on the dynamical substitutes and the DROs is investigated under the full force model. Then, taking a translunar orbit as an example, the constellation’s navigation performance based on inter-satellite range observation is evaluated. With range errors of 1, 10, and 100 m, respectively, the navigation capability of the constellation is successfully verified in the sense that the accuracy of the determined orbit reaches the level of the observation data. From the viewpoint of stable autonomous navigation, the current results are meaningful and deserve further consideration when deploying the navigation constellation in the Earth–Moon system.
随着在半月空间和深空的活动越来越多，迫切需要一种能够为半月甚至深空任务提供自主导航服务的导航系统。本文提出了一种新型导航星座，它被置于两种特殊轨道上，即三角形天平点周围的动力替代轨道和遥远逆行轨道（DRO）。这两种轨道在全力模型下具有相同的长期稳定性，因此无需轨道控制，可以在没有地面支持的情况下自主运行。首先，利用卫星间距数据，研究了在全力模型下，导航卫星在动力替代物和 DROs 上的自主轨道确定。然后，以平移轨道为例，评估了基于卫星间测距观测的星座导航性能。在测距误差分别为 1 米、10 米和 100 米的情况下，成功验证了星座的导航能力，即确定的轨道精度达到了观测数据的水平。从稳定自主导航的角度来看，目前的结果是有意义的，值得在地月系统中部署导航星座时进一步考虑。
{"title":"A novel autonomous navigation constellation in the Earth–Moon system","authors":"Bin Liu, Hengnian Li, Xiyun Hou, Jie Yang, Zongbo Huyan","doi":"10.1515/astro-2022-0203","DOIUrl":"https://doi.org/10.1515/astro-2022-0203","url":null,"abstract":"With more and more activities in cislunar space and deep space, a navigation system that can provide autonomous navigation service for cislunar or even deep space missions has become an urgent need. This article proposes a new type of navigation constellation which is placed on two kinds of special orbits, namely the dynamical substitutes around the triangular libration points and the distant retrograde orbits (DROs). Both types of orbits have the same characteristics of long-term stability under the full force model, so no orbit control is needed and it can operate autonomously without ground support. First, using inter-satellite range data, the autonomous orbit determination between navigation satellites on the dynamical substitutes and the DROs is investigated under the full force model. Then, taking a translunar orbit as an example, the constellation’s navigation performance based on inter-satellite range observation is evaluated. With range errors of 1, 10, and 100 m, respectively, the navigation capability of the constellation is successfully verified in the sense that the accuracy of the determined orbit reaches the level of the observation data. From the viewpoint of stable autonomous navigation, the current results are meaningful and deserve further consideration when deploying the navigation constellation in the Earth–Moon system.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"31 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ireneusz Wlodarczyk, Kazimieras Černis, Ilgmar Eglitis
We discovered 83 asteroids at the Baldone Astrophysical Observatory (MPC code 069) in 2017–2022. We studied one of the dynamically interesting Apollo (Near Earth object) observed at the Baldone Astronomical Observatory, namely 428694 Saule (2008 OS9) and the Centaur-type asteroid 330836 Orius (2009 HW77). We studied the evolution of the asteroid Saule’s rotation period, obliquity, and spin axis together with its non-gravitational parameter da∕dt{rm{d}}a/{rm{d}}t connected with the Yarkovsky effect. Additionally, we studied the orbit of the Amor-type asteroid 2017 UW42, which has the significant non-gravitational parameter A2A2.
2017-2022年，我们在巴尔东天体物理观测台（MPC代码069）发现了83颗小行星。我们研究了巴尔多内天文台观测到的其中一颗动态有趣的阿波罗（近地天体），即 428694 Saule（2008 OS9）和半人马型小行星 330836 Orius（2009 HW77）。我们研究了小行星Saule的自转周期、斜度和自旋轴的演变，以及其与雅科夫斯基效应有关的非重力参数d a ∕ d t {rm{d}}a/{rm{d}}t 。此外，我们还研究了阿莫尔型小行星 2017 UW42 的轨道，它具有重要的非重力参数 A 2 A2。
{"title":"Asteroids discovered in the Baldone Observatory between 2017 and 2022: The orbits of asteroid 428694 Saule and 330836 Orius","authors":"Ireneusz Wlodarczyk, Kazimieras Černis, Ilgmar Eglitis","doi":"10.1515/astro-2024-0004","DOIUrl":"https://doi.org/10.1515/astro-2024-0004","url":null,"abstract":"We discovered 83 asteroids at the Baldone Astrophysical Observatory (MPC code 069) in 2017–2022. We studied one of the dynamically interesting Apollo (Near Earth object) observed at the Baldone Astronomical Observatory, namely 428694 Saule (2008 OS9) and the Centaur-type asteroid 330836 Orius (2009 HW77). We studied the evolution of the asteroid Saule’s rotation period, obliquity, and spin axis together with its non-gravitational parameter <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2024-0004_eq_001.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi mathvariant=\"normal\">d</m:mi> <m:mi>a</m:mi> <m:mo>∕</m:mo> <m:mi mathvariant=\"normal\">d</m:mi> <m:mi>t</m:mi> </m:math> <jats:tex-math>{rm{d}}a/{rm{d}}t</jats:tex-math> </jats:alternatives> </jats:inline-formula> connected with the Yarkovsky effect. Additionally, we studied the orbit of the Amor-type asteroid 2017 UW42, which has the significant non-gravitational parameter <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2024-0004_eq_002.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi>A</m:mi> <m:mn>2</m:mn> </m:math> <jats:tex-math>A2</jats:tex-math> </jats:alternatives> </jats:inline-formula>.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"133 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The all-electric propulsion Geostationary Earth Orbit (GEO) satellite, characterized by its low launch cost, high precision control, and long operational lifespan, has become a focal point in aerospace research worldwide. During its orbital transfer control, this satellite continuously performs weak maneuvers across various orbits including LEO, MEO, and GEO, creating a potential “weavin” effect with other space objects, thereby dramatically increasing the risk of collisions. To effectively mitigate collision risks, this article proposes a collision warning analysis strategy based on deviation orbits. Through the categorization of warning space domain interval level, deviation orbit coverage calculation, and dynamic analysis of control parameters, a collision warning success rate of 100% is ensured. In addition, a collision avoidance algorithm based on deviation orbit control strategy is established, ensuring a 100% success rate in collision avoidance through precision calibration of electric thrust, optimization of deviation orbit control strategy, and autonomous generation of control strategy. Furthermore, a dynamic intelligent collision avoidance model based on orbit prediction error compensation is designed. By constructing an orbit prediction error analysis model, error learning model, and error compensation model, perturbation error in the orbit model are corrected, leading to an accuracy improvement of over 25% in prediction. The experimental results validate the correctness and effectiveness of the proposed methods, ensuring the safety requirements for collision warning and avoidance during the orbital transfer control process of all-electric propulsion GEO satellites.
{"title":"Intelligent collision avoidance strategy for all-electric propulsion GEO satellite orbit transfer control","authors":"Yue Yang, Yuanhui Hao, Liangjun Ke, Jiangong Liu, Jingqi Huang","doi":"10.1515/astro-2024-0005","DOIUrl":"https://doi.org/10.1515/astro-2024-0005","url":null,"abstract":"The all-electric propulsion Geostationary Earth Orbit (GEO) satellite, characterized by its low launch cost, high precision control, and long operational lifespan, has become a focal point in aerospace research worldwide. During its orbital transfer control, this satellite continuously performs weak maneuvers across various orbits including LEO, MEO, and GEO, creating a potential “weavin” effect with other space objects, thereby dramatically increasing the risk of collisions. To effectively mitigate collision risks, this article proposes a collision warning analysis strategy based on deviation orbits. Through the categorization of warning space domain interval level, deviation orbit coverage calculation, and dynamic analysis of control parameters, a collision warning success rate of 100% is ensured. In addition, a collision avoidance algorithm based on deviation orbit control strategy is established, ensuring a 100% success rate in collision avoidance through precision calibration of electric thrust, optimization of deviation orbit control strategy, and autonomous generation of control strategy. Furthermore, a dynamic intelligent collision avoidance model based on orbit prediction error compensation is designed. By constructing an orbit prediction error analysis model, error learning model, and error compensation model, perturbation error in the orbit model are corrected, leading to an accuracy improvement of over 25% in prediction. The experimental results validate the correctness and effectiveness of the proposed methods, ensuring the safety requirements for collision warning and avoidance during the orbital transfer control process of all-electric propulsion GEO satellites.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"68 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In planetary surfaces, oblique impact events are commonplace, and their study holds significant importance for understanding planetary impact processes and aiding in the design of landers and impactors. Current research predominantly focuses on simplified models to study the force and motion under vertical impact craters in terms of scale and impact loading. For oblique impacts, investigations have primarily concentrated on the final crater shape. However, the specific influence of impact load motion on particle bed movement and the precise impact angle’s effect on the ultimate crater shape during the impact process remain unclear. In this study, we used a custom-built oblique impact experimental setup to analyze changes in the velocity field of the particle bed and the horizontal movement of the impact load. Using quasi-static region to assess ellipticity, we aimed to reveal the state of particle movement during oblique impacts and explore the impact of impact angles and energies on crater formation. The results indicate that under large impact angles, the obliquely acquired kinetic energy is minimal, leading to a predominant static point source movement of the particle bed. At higher energy levels, the impact load primarily excavates downward, resulting in the formation of circular impact craters. These findings underscore the sensitivity of particle bed motion to impact angles, making it a crucial metric for assessing the impact of oblique angles on final crater morphology.
{"title":"Stability of granular media impacts morphological characteristics under different impact conditions","authors":"Yifeng Wang, Ran Li, Zhipeng Chi, Hui Yang","doi":"10.1515/astro-2024-0002","DOIUrl":"https://doi.org/10.1515/astro-2024-0002","url":null,"abstract":"In planetary surfaces, oblique impact events are commonplace, and their study holds significant importance for understanding planetary impact processes and aiding in the design of landers and impactors. Current research predominantly focuses on simplified models to study the force and motion under vertical impact craters in terms of scale and impact loading. For oblique impacts, investigations have primarily concentrated on the final crater shape. However, the specific influence of impact load motion on particle bed movement and the precise impact angle’s effect on the ultimate crater shape during the impact process remain unclear. In this study, we used a custom-built oblique impact experimental setup to analyze changes in the velocity field of the particle bed and the horizontal movement of the impact load. Using quasi-static region to assess ellipticity, we aimed to reveal the state of particle movement during oblique impacts and explore the impact of impact angles and energies on crater formation. The results indicate that under large impact angles, the obliquely acquired kinetic energy is minimal, leading to a predominant static point source movement of the particle bed. At higher energy levels, the impact load primarily excavates downward, resulting in the formation of circular impact craters. These findings underscore the sensitivity of particle bed motion to impact angles, making it a crucial metric for assessing the impact of oblique angles on final crater morphology.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"38 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zongbo Huyan, Dapeng Zhang, Pengbin Ma, Hengnian Li, Zhai Min
To meet various requirements of the future deep space missions of China, State Key Laboratory of Astronautic Dynamics constructs a new orbit determinatin software with parallel observations process. By using 32 threads, the computational efficiency per iteration (including spacecraft’s integration) could be promoted to 10 times as that of single-threaded orbit determination. Suppose the number of observations is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_astro-2022-0202_eq_001.png"/> <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>p</m:mi> </m:math> <jats:tex-math>p</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the number of estimated parameters (including spacecraft’s state) is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_astro-2022-0202_eq_002.png"/> <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>q</m:mi> </m:math> <jats:tex-math>q</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the amount of computation of one observation is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_astro-2022-0202_eq_003.png"/> <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>x</m:mi> </m:math> <jats:tex-math>x</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the amount of computation of one Givens transformation is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_astro-2022-0202_eq_004.png"/> <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>y</m:mi> </m:math> <jats:tex-math>y</jats:tex-math> </jats:alternatives> </jats:inline-formula> and the best number of threads is proved to be <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_astro-2022-0202_eq_005.png"/> <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msup> <m:mrow> <m:mrow> <m:mo>[</m:mo> <m:mrow> <m:mi>p</m:mi> <m:mo>⋅</m:mo> <m:mrow> <m:mo>(</m:mo> <m:mrow> <m:mi>x</m:mi> <m:mo>+</m:mo> <m:mi>y</m:mi> </m:mrow> <m:mo>)</m:mo> </m:mrow> <m:mspace width="0.1em"/> <m:mtext>/</m:mtext> <m:mspace width="0.1em"/> <m:mrow> <m:mo>(</m:mo> <m:mrow> <m:mi>q</m:mi> <m:mo>⋅</m:mo> <m:mi>y</m:mi> </m:mrow> <m:mo>)</m:mo> </m:mrow> </m:mrow> <m:mo>]</m:mo> </m:mrow> </m:mrow> <m:mrow> <m:mn>1</m:mn> <m:mspace width="0.1em"/> <m:mtext>/</m:mtext> <m:mspace width="0.1em"/> <m:mn>2</m:mn> </m:mrow> </m:msup> </m:math> <jats:tex-math>{left[pcdot left(x+y)text{/}left(qcdot y)]}^{1text{/}2}</jats:tex-math> </jats:alternatives> </jats:inline-formula> for one-step threads combination. The root mean square of the postfit residuals of China’s deep space monitoring network (CDSMN) and China’s Very Long Baseline Interferometry (VLBI) network (CV
为满足中国未来深空任务的各种要求，航天动力学国家重点实验室构建了一种新型并行观测过程的定轨软件。通过使用 32 个线程，每次迭代的计算效率（包括航天器的积分）可提高到单线程定轨的 10 倍。假设观测数据的数量为 p p，估计参数（包括航天器状态）的数量为 q q，一个观测数据的计算量为 x x 、一步线程组合的最佳线程数为 [ p ⋅ ( x + y ) / ( q ⋅ y ) ] 1 / 2 {left[pcdot left(x+y)text{/}left(qcdot y)]}^{1/text{/}2}。中国深空监测网（CDSMN）和中国甚长基线干涉测量（VLBI）网（CVN）在地-火星转移阶段和火星入轨阶段的观测后拟合残差的均方根基本相同：Ranging约为0.3 m，Doppler约为0.3 mm/s，VLBI延迟约为3 cm，VLBI延迟率约为0.5 mm/s。研究还发现，在进行深空机动和近地轨道制动计算的轨道确定时，需要对 CDSMN 和 CVN 进行所有四种类型的观测。在火星轨道阶段，仅在 CDSMN 跟踪模式下确定轨道后的位置精度可达 1 公里左右。
{"title":"Parallel observations process of Tianwen-1 orbit determination","authors":"Zongbo Huyan, Dapeng Zhang, Pengbin Ma, Hengnian Li, Zhai Min","doi":"10.1515/astro-2022-0202","DOIUrl":"https://doi.org/10.1515/astro-2022-0202","url":null,"abstract":"To meet various requirements of the future deep space missions of China, State Key Laboratory of Astronautic Dynamics constructs a new orbit determinatin software with parallel observations process. By using 32 threads, the computational efficiency per iteration (including spacecraft’s integration) could be promoted to 10 times as that of single-threaded orbit determination. Suppose the number of observations is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0202_eq_001.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi>p</m:mi> </m:math> <jats:tex-math>p</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the number of estimated parameters (including spacecraft’s state) is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0202_eq_002.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi>q</m:mi> </m:math> <jats:tex-math>q</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the amount of computation of one observation is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0202_eq_003.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi>x</m:mi> </m:math> <jats:tex-math>x</jats:tex-math> </jats:alternatives> </jats:inline-formula>, the amount of computation of one Givens transformation is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0202_eq_004.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mi>y</m:mi> </m:math> <jats:tex-math>y</jats:tex-math> </jats:alternatives> </jats:inline-formula> and the best number of threads is proved to be <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0202_eq_005.png\"/> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:msup> <m:mrow> <m:mrow> <m:mo>[</m:mo> <m:mrow> <m:mi>p</m:mi> <m:mo>⋅</m:mo> <m:mrow> <m:mo>(</m:mo> <m:mrow> <m:mi>x</m:mi> <m:mo>+</m:mo> <m:mi>y</m:mi> </m:mrow> <m:mo>)</m:mo> </m:mrow> <m:mspace width=\"0.1em\"/> <m:mtext>/</m:mtext> <m:mspace width=\"0.1em\"/> <m:mrow> <m:mo>(</m:mo> <m:mrow> <m:mi>q</m:mi> <m:mo>⋅</m:mo> <m:mi>y</m:mi> </m:mrow> <m:mo>)</m:mo> </m:mrow> </m:mrow> <m:mo>]</m:mo> </m:mrow> </m:mrow> <m:mrow> <m:mn>1</m:mn> <m:mspace width=\"0.1em\"/> <m:mtext>/</m:mtext> <m:mspace width=\"0.1em\"/> <m:mn>2</m:mn> </m:mrow> </m:msup> </m:math> <jats:tex-math>{left[pcdot left(x+y)text{/}left(qcdot y)]}^{1text{/}2}</jats:tex-math> </jats:alternatives> </jats:inline-formula> for one-step threads combination. The root mean square of the postfit residuals of China’s deep space monitoring network (CDSMN) and China’s Very Long Baseline Interferometry (VLBI) network (CV","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"33 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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 in many areas of science and has found application in many branches of physical science. This work uses the series expansion method to examine N-dimensional polytropes (i.e., slab, cylinder, and sphere). To solve LE-type equations, a computational method based on accelerated series expansion (ASE) is applied. We calculate several models for the N-dimensional polytropes. The numerical results show good agreement between the ASE and numerical and analytical models of the N-dimensional polytropes.
多向方程（Lane-Emden[LE]方程）非常有价值，因为它们为恒星的内部结构、星际物质、分子云甚至旋臂提供了一个简单的解释，可以计算并用于估算各种物理参数。许多分析和数值方法都被用来求解多向性 LE 方程。数列展开法在许多科学领域发挥了重要作用，并在物理科学的许多分支中得到了应用。本研究使用数列展开法研究 N 维多向性（即板、圆柱和球体）。为了求解 LE 型方程，我们采用了基于加速序列展开（ASE）的计算方法。我们计算了 N 维多质体的几个模型。数值结果表明，ASE 与 N 维多质体的数值模型和分析模型之间具有良好的一致性。
{"title":"Computing N-dimensional polytrope via power series","authors":"Mohamed I. Nouh, Mahmoud Taha, Ahmed Ahmed Ibrahim, Mohamed Abdel-Sabour","doi":"10.1515/astro-2022-0230","DOIUrl":"https://doi.org/10.1515/astro-2022-0230","url":null,"abstract":"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 in many areas of science and has found application in many branches of physical science. This work uses the series expansion method to examine <jats:italic>N</jats:italic>-dimensional polytropes (<jats:italic>i.e.</jats:italic>, slab, cylinder, and sphere). To solve LE-type equations, a computational method based on accelerated series expansion (ASE) is applied. We calculate several models for the <jats:italic>N</jats:italic>-dimensional polytropes. The numerical results show good agreement between the ASE and numerical and analytical models of the <jats:italic>N</jats:italic>-dimensional polytropes.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"35 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140579807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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 comet C/1652 Y1 among Korean documents and presented the translations in the Appendix for future reference. We then compared the Korean observations with the orbital path determined from calculations using the orbital elements provided by Marsden (1983. Catalog of cometary orbit. Hillside: Enslow Publishers). We also compared the illustrations depicted by Weigelius and Schiltero (1653. Commentatio astronomica de cometa novo qui sub finem anni 1652 lumine sub obscuro nobis illuxit. Jenae: Typis Georgii Sengenvvaldi) and by Hevelius (1668. Cometographia, Totam Naturam Cometarum; Exhibens. Gedani: Typis Auctoris, & Sumptibus, Simon Reiniger). Cf) Marsden (1983. Catalog of cometary orbit. Hillside: Enslow Publishers). orbit. Hillside: Enslow Publishers). We found that the Korean observations show discrepancies with the orbital path calculated by Marsden and the illustration of Weigelius and Schiltero, particularly near the end of the observation period. In conclusion, we believe that this study will contribute to improving the orbital path calculation of comet C/1652 Y1.
我们报告了韩国关于 C/1652 Y1 彗星的记录，这些记录在以往的历史彗星研究中从未出现过。根据韩国的历史文献，这颗彗星被描述为 "白星 "或 "客星"，在1652年12月19日至1653年1月9日期间被肉眼观测了22天。在这项研究中，我们首先核对了韩国文献中关于 C/1652 Y1 彗星的记录，并将译文放在附录中，以供今后参考。然后，我们将韩国的观测结果与使用马斯登（Marsden）（1983 年。我们还比较了 Weigelius 和 Schiltero（1653.Commentatio astronomica de cometa novo qui sub finem anni 1652 lumine sub obscuro nobis illuxit.Jenae：Typis Georgii Sengenvvaldi）和海维留斯（1668.Cometographia, Totam Naturam Cometarum; Exhibens.Gedani: Typis Auctoris, & Sumptibus, Simon Reiniger）。参阅）Marsden（1983 年.彗星轨道目录.Hillside：Enslow 出版社）.轨道.Hillside：Enslow Publishers）。我们发现，韩国的观测结果与马斯登计算出的轨道路径以及魏格柳斯和希尔特罗的图示存在差异，尤其是在观测期接近尾声时。总之，我们相信这项研究将有助于改进 C/1652 Y1 彗星的轨道路径计算。
{"title":"Observations of comet C/1652 Y1 recorded in Korean histories","authors":"Uhn Mee Bahk, Ki-Won Lee, Byeong-Hee Mihn, Sang Hyuk Kim","doi":"10.1515/astro-2024-0001","DOIUrl":"https://doi.org/10.1515/astro-2024-0001","url":null,"abstract":"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 <jats:italic>bai xing</jats:italic> (white star, in literal) or <jats:italic>ke xing</jats:italic> (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 comet C/1652 Y1 among Korean documents and presented the translations in the Appendix for future reference. We then compared the Korean observations with the orbital path determined from calculations using the orbital elements provided by Marsden (1983. Catalog of cometary orbit. Hillside: Enslow Publishers). We also compared the illustrations depicted by Weigelius and Schiltero (1653. Commentatio astronomica de cometa novo qui sub finem anni 1652 lumine sub obscuro nobis illuxit. Jenae: Typis Georgii Sengenvvaldi) and by Hevelius (1668. Cometographia, Totam Naturam Cometarum; Exhibens. Gedani: Typis Auctoris, & Sumptibus, Simon Reiniger). Cf) Marsden (1983. Catalog of cometary orbit. Hillside: Enslow Publishers). orbit. Hillside: Enslow Publishers). We found that the Korean observations show discrepancies with the orbital path calculated by Marsden and the illustration of Weigelius and Schiltero, particularly near the end of the observation period. In conclusion, we believe that this study will contribute to improving the orbital path calculation of comet C/1652 Y1.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"35 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140579810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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 are lacking. In this paper, we provide a solution and implement a GNSS data visualization system based on MapV and cesium running on the Hadoop platform, which can effectively solve the problems of the lack of storage and computing resources for these massive multisource heterogeneous data. The proposed system provides multidimensional presentations to show how the space and ground segments of the entire system are organized by analyzing GNSS data.
{"title":"Multidimensional visualization analysis based on large-scale GNSS data","authors":"Jingyan Wang, Ronghui Wang, Zhenyong Bo, Hengnian Li, Chong Wang, Yanan Fang","doi":"10.1515/astro-2022-0037","DOIUrl":"https://doi.org/10.1515/astro-2022-0037","url":null,"abstract":"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 are lacking. In this paper, we provide a solution and implement a GNSS data visualization system based on MapV and cesium running on the Hadoop platform, which can effectively solve the problems of the lack of storage and computing resources for these massive multisource heterogeneous data. The proposed system provides multidimensional presentations to show how the space and ground segments of the entire system are organized by analyzing GNSS data.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"159 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140168049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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 (SDN) technology. This article proposes a new network architecture based on a unicast/multicast protocol for data interaction between the SDN and IP network. There are three main contributions of this article. The first is that the architecture proposed in this article aims to reduce end-to-end transmission latency and packet loss. The second is to improve the flexibility of system configuration and precise control when the SND controller state changes. The third is to verify the feasibility of deploying network architecture in a real data center environment.
商业航天器在轨产生的海量数据日益增多，对商业航天数据中心计算机系统的稳定性、可靠性和计算能力提出了越来越高的要求。数据中心计算机系统正逐步从 X86 架构和 IP 网络模式向云计算和软件定义网络（SDN）技术的平台模式转变。本文提出了一种基于单播/多播协议的新型网络架构，用于 SDN 和 IP 网络之间的数据交互。本文有三个主要贡献。首先，本文提出的架构旨在减少端到端传输延迟和数据包丢失。二是提高系统配置的灵活性和 SND 控制器状态变化时的精确控制。第三是验证在真实数据中心环境中部署网络架构的可行性。
{"title":"Application of SDN-IP hybrid network multicast architecture in Commercial Aerospace Data Center","authors":"Chen Gang, Chen Guangyu, Tong Xin, Ren Qiaoyan, Kuang Dongmei","doi":"10.1515/astro-2022-0223","DOIUrl":"https://doi.org/10.1515/astro-2022-0223","url":null,"abstract":"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 (SDN) technology. This article proposes a new network architecture based on a unicast/multicast protocol for data interaction between the SDN and IP network. There are three main contributions of this article. The first is that the architecture proposed in this article aims to reduce end-to-end transmission latency and packet loss. The second is to improve the flexibility of system configuration and precise control when the SND controller state changes. The third is to verify the feasibility of deploying network architecture in a real data center environment.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"51 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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, serving as fuel for galactic nucleus activity, resides within the central region during the retrograde infall of gas at an incident angle of approximately 20°2{0}^{^circ } relative to the galactic plane. Departures from this angle significantly diminish the gas flow rate towards the galactic centre. Conversely, the prograde infall of intergalactic gas makes a marginal contribution to the gas content in the central region and cannot supply fuel to the active galactic nucleus. An intriguing characteristic of the observed retrograde impact is the emergence of a rotating polar ring at the galaxy’s periphery, primarily originating from intergalactic gas.
{"title":"Retrograde infall of the intergalactic gas onto S-galaxy and activity of galactic nuclei","authors":"Sergey S. Khrapov, Alexander V. Khoperskov","doi":"10.1515/astro-2022-0231","DOIUrl":"https://doi.org/10.1515/astro-2022-0231","url":null,"abstract":"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, serving as fuel for galactic nucleus activity, resides within the central region during the retrograde infall of gas at an incident angle of approximately <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_astro-2022-0231_eq_001.png\" /> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\"> <m:mn>2</m:mn> <m:msup> <m:mrow> <m:mn>0</m:mn> </m:mrow> <m:mrow> <m:mrow> <m:mo>°</m:mo> </m:mrow> </m:mrow> </m:msup> </m:math> <jats:tex-math>2{0}^{^circ }</jats:tex-math> </jats:alternatives> </jats:inline-formula> relative to the galactic plane. Departures from this angle significantly diminish the gas flow rate towards the galactic centre. Conversely, the prograde infall of intergalactic gas makes a marginal contribution to the gas content in the central region and cannot supply fuel to the active galactic nucleus. An intriguing characteristic of the observed retrograde impact is the emergence of a rotating polar ring at the galaxy’s periphery, primarily originating from intergalactic gas.","PeriodicalId":19514,"journal":{"name":"Open Astronomy","volume":"45 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140070991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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