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131.
W.D. Apel J.C. Arteaga L. Bähren K. Bekk M. Bertaina P.L. Biermann J. Blümer H. Bozdog I.M. Brancus P. Buchholz S. Buitink E. Cantoni A. Chiavassa K. Daumiller V. de Souza F. Di Pierro P. Doll M. Ender R. Engel H. Falcke M. Finger D. Fuhrmann H. Gemmeke C. Grupen A. Haungs D. Heck J.R. Hörandel A. Horneffer D. Huber T. Huege P.G. Isar K.-H. Kampert D. Kang O. Krömer J. Kuijpers K. Link P. Łuczak M. Ludwig H.J. Mathes M. Melissas C. Morello S. Nehls J. Oehlschläger N. Palmieri T. Pierog J. Rautenberg H. Rebel M. Roth C. Rühle A. Saftoiu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
132.
Carlo Scotto 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
A long temporal series of simulated ionograms was generated with a superimposed secular variation of −14 km/century on the hmF2 parameter. These ionograms were interpreted by the automatic scaling program Autoscala. By applying four different empirical formulas, four artificial series of hmF2 were generated and then processed with the same methods used by other authors for real data sets. Data analysis of the simulated ionograms revealed the artificially imposed long-term trend. These results lead to the conclusion, that regardless of the empirical formula used, the accuracy of hmF2 from ionosonde measurements would be adequate to observe a long-term trend of −14 km/century. 相似文献
133.
134.
NONLINEARPREDICTIVECONTROLFORTERRAINFOLLOWINGCuiHutao(崔祜涛),GengYunhai(耿云海),YangDi(杨涤)(HarbinInstituteofTechnology,P.O.Box137,... 相似文献
135.
Kaichang Di Wenmin Hu Yiliang Liu Man Peng 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012,50(12):1615-1628
Topographic information is of fundamental importance for various scientific investigations in lunar and planetary exploration. To provide high-precision, seamless mapping capability, it is critical to co-register image and altimetry data, the two major data sources for topographic modeling. This paper presents a method for co-registration of Chang’E-1 (CE-1) stereo images and laser altimeter (LAM) data with crossover adjustment and refinement of the image sensor model. The crossover adjustment is tested in a larger area (0–60°N, 50–0°W); the image refinement and co-registration with LAM data are tested in an area (46.2–50.0°N, 31.8–28.8°W) within the larger area. Experimental results demonstrate that this co-registration reduces the mean differences of inconsistency from more than 200 m to just 3.21 m in the Z direction of object space. In image space, the mean errors of homologous points both in the column and row directions are reduced to below 0.1 pixel. This indicates that the proposed crossover adjustment of LAM data and refinement of the CE-1 stereo image model can effectively improve co-registration of the two data sets. 相似文献
136.
在固定单站无源定位算法中,基于角度(Direct of Arrival)、角度变化率(Direct of Arrival Rate-of-Change)、多普勒频率(Doppler Frequency)和多普勒频率变化率(Doppler Frequency Rate-of-Change)4个观测信息实现定位(即DDFRC定位)算法仅通过单次观测即可实现对目标辐射源的定位。文中通过转移观测的卡尔曼滤波对定位结果进行平滑,较原有算法拥有更好的跟踪效果。同时,对定位误差进行了定量分析,并将距离信息引入算法的仿真分析之中,详细讨论了各个观测量误差在不同距离时对算法定位性能的影响,根据仿真结果,结合定位误差的定量分析对算法性能做出评价。通过仿真分析,得到了定位算法对不同距离下各参数的精度要求,从而为在实际系统中使用该定位算法提供了参考。 相似文献
137.
在计算流体力学(CFD)方法中,限制技术是影响计算精度和计算稳定性的重要因素,目前应用较广的经典二阶总变差衰减(TVD)限制器虽能较好地满足计算要求,但性能差异大且分辨率和耗散的性能间并未得到良好权衡。对一种新型的三阶TVD插值限制器(T-3限制器)进行了研究并将其与3种经典限制器进行对比。首先通过一维黎曼问题,得出T-3限制器兼顾较高间断分辨率和良好稳定性的特点;接着通过高超声速双锥绕流和X-33外形飞行器的数值实验,得到T-3限制器具有刻画复杂流动的能力以及较优的气动热计算性能。 相似文献
138.
A high order method for orbital conjunctions analysis: Sensitivity to initial uncertainties 总被引:1,自引:0,他引:1
Alessandro Morselli Roberto Armellin Pierluigi Di Lizia Franco Bernelli Zazzera 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
A high order method to quickly assess the effect that uncertainties produce on orbital conjunctions through a numerical high-fidelity propagator is presented. In particular, the dependency of time and distance of closest approach to initial uncertainties on position and velocity of both objects involved in a conjunction is studied. The approach relies on a numerical integration based on differential algebraic techniques and a high-order algorithm that expands the time and distance of closest approach in Taylor series with respect to relevant uncertainties. The modeled perturbations are atmospheric drag, using NRLMSISE-00 air density model, solar radiation pressure with shadow, third body perturbation using JPL’s DE405 ephemeris, and EGM2008 gravity model. The polynomial approximation of the final position is used as an input to compute analytically the expansion of time and distance of closest approach. As a result, the analysis of a close encounter can be performed through fast, multiple evaluations of Taylor polynomials. Test cases with objects ranging from LEO to GEO regimes are considered to assess the performances and the accuracy of the proposed method. 相似文献
139.
以思想政治教育发生为视角对大学生思想政治教育进行研究,不仅能深化对思想政治教育的研究,而且对思想政治教育的有效性和实效性、凝聚力和向心力的提高具有一定的作用。以思想政治教育为视角,探讨大学生思想政治教育,以期提高大学生思想政治教育的有效性和实效性。 相似文献
140.