共查询到18条相似文献,搜索用时 703 毫秒
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针对低轨同构星座覆盖资源在纬度上分布不均匀的不足,提出采用低轨混合星座提升覆盖均匀性的设计方案,并推导了满足全球任意点平均每天覆盖一定次数的最小卫星规模估算公式。针对非支配近邻免疫算法(NNIA)约束处理方面的不足,提出基于约束支配的改进非支配近邻免疫算法(Modified NNIA),并以此设计了一种低轨混合星座优化平台来优化带约束的星座设计问题。仿真结果表明,改进的NNIA算法在收敛速度和多样性上均优于非支配分层遗传算法(NSGA II)和多目标粒子群算法(MOPSO),可大大提高星座设计的效率。同时优化结果也表明低轨混合星座可提高覆盖的均匀性和大部分区域的覆盖次数,进而减少特定覆盖要求所需的卫星数目。 相似文献
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针对期望覆盖重数为偶数重时连续覆盖Walker星座的构型设计问题,提出一种基于覆盖带理论的构型设计方法。首先分析同轨道卫星组成覆盖带时的构型设计特例,随后将结论推广,改进了传统Walker星座的构型表征形式并提出覆盖带构型参数。基于轨道参数的相平面映射,给出了异轨卫星组成覆盖带时特征宽度的计算方法。通过分析相平面上覆盖带的拼接情况,给出了轨道倾角的优化策略和偶数重覆盖任意纬度的Walker星座设计步骤。所提出方法能显著提高构型枚举效率,且能满足不同纬度范围的覆盖需求。仿真表明,该方法能减少约10%覆盖所需的卫星数量,并能通过调整构型参数进一步优化轨道面数量。 相似文献
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在卫星星座优化设计与性能分析过程中,根据球面Delaunay三角网和Voronoi图的特性,首先研究了任意状态下星座空间几何构形划分方法,定义了卫星所属覆盖区域。然后,通过分析卫星星座和地面目标区域之间的几何关系,提出了星座对任意类型地面目标的最小观测仰角和平均观测仰角的确定性计算方法。在此基础上,分析了基于星座空间几何构形划分的卫星系统网络的时变特性,提出了星间通信链路快速建立方法。最后,以铱星系统为例,分析了该系统的对地覆盖能力和星间链路通信能力。实验结果表明该方法不仅可以准确、快速的评估卫星系统应用效能,同时能够为星座优化设计人员提供必要的决策支持。 相似文献
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针对探测冷背景条件下的空间目标的红外低轨系统,分析了红外低轨星座中凝视传感器对空间目标的探测特点,建立了红外凝视传感器的几何观测模型,考虑其探测距离和范围的约束,提出了一种红外凝视传感器对空间区域的覆盖判定方法,并给了一组表征星座凝视传感器对空间区域覆盖性能的指标。基于点覆盖数值仿真方法,得到了典型红外低轨星座凝视传感器的多重覆盖空间高度分层分布、纬度带多重几何覆盖分布以及立体空间区域多重覆盖高度分布等方面的性能特征,可以体现星座对空间立体区域覆盖的差异性。仿真结果表明了覆盖判别方法和空间覆盖性能指标的有效性,结论可为红外低轨星座设计及其空间应用设计提供一定的参考依据。 相似文献
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提出了描述红外低轨星座对空间观测性能的指标,依据纬度威胁分布特性,提出了纬度区域优化的加权星座观测性能评估方法。考虑空间多重覆盖性能、成本、无源定位精度及碰撞等因素,建立了优化目标函数,基于通用差异演化算法(GDE3)得到了一组Pareto解,在此基础上,利用一种适于多属性星座方案的折中选择策略,得到了对重点关注纬度区域有良好观测性能的红外低轨星座方案。最后,通过仿真验证了算法有效性,分析和对比了星座的空间观测性能,证明设计方法和星座方案的合理性,具有重大的现实意义和社会价值。 相似文献
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V. K. Saulskiy 《Cosmic Research》2016,54(4):313-324
Single satellites and multisatellite constellations for the periodic coverage of the Earth are considered. The main feature is the use of several cameras with different swath widths. A vector method is proposed which makes it possible to find orbits minimizing the periodicities of coverage of a given area of Earth uniformly for all swaths. Their number is not limited, but the relative dimensions should satisfy the Fibonacci series or some new numerical sequences. The results apply to constellations of any number of satellites. Formulas were derived for calculating their structure, i.e., relative position in the constellation. Examples of orbits and the structure of constellations for the Earth’s multiswath coverage are presented. 相似文献
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针对商业小卫星星座迅猛发展对航天器飞行安全造成潜在威胁的问题,以600 km高度星座和大型低轨航天器为研究对象,通过区域方法(BOX)和碰撞概率风险评估方法,分析了星座与大型低轨航天器的碰撞风险。根据星座轨道演化分析表明,整个星座卫星与大型低轨航天器可能发生碰撞的时间相对集中,持续时间约 1~ 2年。BOX方法计算结果表明,每颗卫星与大型低轨航天器交会,并进入红色预警门限的交会次数约10次左右。碰撞概率计算结果表明,约有5%的卫星进入红色预警门限,星座如果在寿命末期采取无控再入将对大型低轨航天器在1~2年内产生较大的威胁。 相似文献
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卫星星座的相对几何和区域覆盖重复周期 总被引:4,自引:0,他引:4
研究了在设计δ星座或者由几个δ星座的某些卫星构成的星座时经常需要考虑的三个问题:任意两颗卫星是否在同一条星下点轨迹上,同一条星下点轨迹上的卫星通过某一区域的相对顺序和星座对某特定区域或地点覆盖重复周期的计算。首先对δ星座中卫星之间的相对几何关系做了详细的分析,给出了第一个问题的判断准则,并进一步导出了位于同一条星下点轨迹上的卫星通过某一指定地区的相对顺序以及相应的时间间隔的计算方法。在解决前两个问题的基础上,针对由一个或几个δ星座(或子星座)构成的设计星座,给出了计算其区域覆盖重复周期的方法。 相似文献
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This paper analyzes an example of a three-dimensional constellation of debris removal satellites and proposes an effective constellation using a delta-V analysis that discusses the advisability of rendezvousing satellites with space debris. Lambert?s Equation was used to establish a means of analysis to construct a constellation of debris removal satellites, which has a limit of delta-V injection by evaluating the amount of space debris that can be rendezvoused by a certain number of removal satellite. Consequently, we determine a constellation of up to 38 removal satellites for debris removal, where the number of space debris rendezvoused by a single removal satellite is not more than 25, removing up to 584 pieces of debris total. Even if we prepare 38 removal satellites in their respective orbits, it is impossible to remove all of the space debris. Although many removal satellites, over 100 for example, can remove most of the space debris, this method is economically disproportionate. However, we can also see the removal satellites are distributed nearly evenly. Accordingly, we propose a practical two-stage strategy. The first stage is to implement emergent debris removal with the 38 removal satellites. When we find a very high probability of collision between a working satellite and space debris, one of the removal satellites in the constellation previously constructed in orbit initiates a maneuver of emergent debris removal. The second stage is a long-term space debris removal strategy to suppress the increase of space debris derived from collisions among the pieces of space debris. The constellation analyzed in this paper, which consists of the first 38 removal satellites, can remove half of the over 1000 dangerous space debris among others, and then the constellation increases the number of the following removal satellites in steps. At any rate, an adequate orbital configuration and constellation form is very important for both space debris removal and economic efficiency. Though the size of constellation of debris removal satellites would be small originally, such a constellation of satellites should be one of the initial constellations of removal satellites to ensure the safety of the future orbital environment. 相似文献
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《中国航天(英文版)》2020,(2)
Large constellations have developed rapidly in recent years because of their unique advantages, but they will inevitably have a major negative impact on the space debris environment, leading to its deterioration. The key to mitigate the impact is the success rate and duration of the post-mission disposal(PMD) process. Aiming at solving this problem, this paper further studies the impact of large constellations on other space assets under different PMD strategies through simulation, and proposes corresponding strategies and suggestions for mitigation.According to OneWeb's large constellation launch plan, the dangerous intersection of the large constellation with existing space assets at different stages of the constellations life cycle is calculated by simulation. Based on this, the influence of the large constellation operation on existing space assets at different times and strategies of PMD is analyzed. The conclusion shows that in the PMD stage, large constellations have the greatest impact on existing space assets; the PMD duration and number of satellites performing PMD at the same time are key factors to the degree of negative impact. The faster the PMD is, the less threat it poses to other spacecraft. More results and conclusions are still being analyzed. 相似文献
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玫瑰星座的优化设计方法 总被引:1,自引:0,他引:1
玫瑰星座是一种均匀分布的星座,常用于全球连续覆盖。本文对玫瑰星座的基本理论进行了论述,提出了玫瑰星座用于实现全球一重连续覆盖时的优化方法。用本文提出的方法对卫星总数多达300的玫瑰星座进行了优化计算并给出了计算结果。 相似文献
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V. K. Saulskiy 《Cosmic Research》2009,47(2):144-155
A new and wider definition is given to multi-satellite systems with linear structure (SLS), and efficiency of their application to multiple continuous coverage of the Earth is substantiated. Owing to this widening, SLS have incorporated already well-recognized “polar systems” by L. Rider and W.S. Adams, “kinematically regular systems” by G.V. Mozhaev, and “delta-systems” by J.G. Walker, as well as “near-polar systems” by Yu.P. Ulybyshev, and some other satellite constellations unknown before. A universal method of SLS optimization is presented, valid for any values of coverage multiplicity and the number of satellites in a system. The method uses the criterion of minimum radius of a circle seen from a satellite on the surface of the globe. Among the best SLS found in this way there are both systems representing the well-known classes mentioned above and new orbit constellations of satellites. 相似文献