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GEO带目标编目库的星历设计
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作者 刘隆迪 杜兰 +3 位作者 张中凯 刘泽军 周佩元 黄俊迦 《导航定位学报》 CSCD 2023年第3期29-37,共9页
针对目前空间目标编目库普遍采用的2行根数——简化常规摄动4/简化深空摄动4(TLE-SGP4/SDP4)模型复杂,源码不公开,且轨道精度不高的问题,提出一种地球同步轨道(GEO)带目标编目库的星历设计方法:基于数值积分的多天精密预报轨道,针对GEO... 针对目前空间目标编目库普遍采用的2行根数——简化常规摄动4/简化深空摄动4(TLE-SGP4/SDP4)模型复杂,源码不公开,且轨道精度不高的问题,提出一种地球同步轨道(GEO)带目标编目库的星历设计方法:基于数值积分的多天精密预报轨道,针对GEO的静地特性,设计19/25/31个参数的无奇点根数型星历模型;并采取定时长和多组星历同步更新策略,适用于数小时至数天的日常预报轨道发布及更新。实验结果表明,3种无奇点根数型星历模型可灵活适应合作/非合作GEO目标的预报轨道精度和预报时长,1 d拟合均方根(RMS)均值分别优于30、10和7 m;当缩短拟合时长至12 h,31参数星历模型的拟合精度可优于0.2 m。 展开更多
关键词 地球同步轨道带 空间编目库 无奇点轨道根数 星历
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基于静地特性的GEO带目标混合函数型星历表征设计
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作者 刘隆迪 杜兰 +3 位作者 刘泽军 张中凯 周佩元 黄俊迦 《全球定位系统》 CSCD 2023年第1期105-110,共6页
地球同步轨道(GEO)卫星带是一类独具高空战略地位的轨道资源.长期以来GEO带编目目标采用双行轨道根数(TLE)和简化常规/深空摄动4模型(SGP4/SDP4)进行通用轨道计算,但该解析算法存在外推精度受限、使用过程复杂、用户难以理解等缺点.本... 地球同步轨道(GEO)卫星带是一类独具高空战略地位的轨道资源.长期以来GEO带编目目标采用双行轨道根数(TLE)和简化常规/深空摄动4模型(SGP4/SDP4)进行通用轨道计算,但该解析算法存在外推精度受限、使用过程复杂、用户难以理解等缺点.本文针对GEO的静地特性,结合经典开普勒根数和多项式-傅里叶级数设计了混合函数型参数星历模型,可用于高精度数值积分轨道的12~24 h轨位拟合和多组星历参数的同步发布,用户计算模型简单.对三颗代表性GEO目标为期一年的星历参数拟合实验表明,1 d拟合均方根(RMS)均值优于20 m;当缩短拟合时长至12 h,拟合精度可优于0.15 m.可为我国空间目标编目库的分级管理提供参考. 展开更多
关键词 地球同步轨道(GEO)卫星 趋势项 周期项 傅里叶级数 星历
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Dynamic variation and the fast acceleration of particles in Earth's radiation belt 被引量:5
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作者 ZONG QiuGang YUAN ChongJing +1 位作者 WANG YongFu SU ZhenPeng 《Science China Earth Sciences》 SCIE EI CAS 2013年第7期1118-1140,共23页
We have quantitatively investigated the radiation belt's dynamic variations of 1.5-6.0 MeV electrons during 54 CME (coronal mass ejection)-driven storms from 1993 to 2003 and 26 CIR (corotating interaction region)... We have quantitatively investigated the radiation belt's dynamic variations of 1.5-6.0 MeV electrons during 54 CME (coronal mass ejection)-driven storms from 1993 to 2003 and 26 CIR (corotating interaction region)-driven recurrent storms in 1995 by utilizing case and statistical studies based on the data from the SAMPEX satellite. It is found that the boundaries determined by fitting an exponential to the flux as a function of L shell obtained in this study agree with the observed outer and inner boundaries of the outer radiation belt. Furthermore, we have constructed the Radiation Belt Content (RBC) index by integrating the number density of electrons between those inner and outer boundaries. According to the ratio of the maximum RBC index during the recovery phase to the pre-storm average RBC index, we conclude that CME-driven storms produce more relativistic electrons than CIR-driven storms in the entire outer radiation belt, although the relativistic electron fluxes during CIR-related storms are much higher than those during CME-related storms at geosynchronous orbit. The physical radiation belt model STEERB is based on the three-dimensional Fokker-Planck equation and includes the physical processes of local wave-particle interactions, radial diffusion, and adiabatic transport. Due to the limitation of numerical schemes, formal radiation belt models do not include the cross diffusion term of local wave-particle interactions. The numerical experiments of STEERB have shown that the energetic electron fluxes can be overestimated by a factor of 5 or even several orders (depending on the pitch angle) if the cross diffusion term is ignored. This implies that the cross diffusion term is indispensable for the evaluation of radiation belt electron fluxes. Formal radiation belt models often adopt dipole magnetic field; the time varying Hilmer-Voigt geomagnetic field was adopted by the STEERB model, which self-consistently included the adiabatic transport process. The test simulations clearly indicate that the adiabatic process can significantly affect the evolution of radiation belt electrons. The interactions between interplanetary shocks and magnetosphere can excite ULF waves in the inner magnetosphere; the excited polodial mode ULF wave can cause the fast acceleration of "killer electrons". The acceleration mechanism of energetic electrons by poloidal and toroidal mode ULF wave is different at different L shells. The acceleration of energetic electrons by the toroidal mode ULF waves becomes important in the region with a larger L shell (the outer magnetosphere); in smaller L shell regions (the inner magnetosphere), the poloidal mode ULF becomes responsible for the acceleration of energetic electrons. 展开更多
关键词 radiation belt killer electrons CME magnetic storm CIR magnetic storm wave-particle interaction ULF wave VLFwave
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