| 射电源结构对VLBI天体测量的影响 |
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| 引用本文： | 夏一飞,高洁.射电源结构对VLBI天体测量的影响[J].时间频率学报,1998,21(1):54-58. |
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| 作者姓名： | 夏一飞 高洁 |
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| 作者单位： | 南京大学天文系!南京，210093，南京大学天文系!南京，210093，南京邮电学院!146信箱，南京，210003 |
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| 摘 要： | 目前利用VLBIMK3系统确定的延迟测量的精度约为30ps，在这样的精度下，改善计算延迟的理论模型，考虑各种微扰改正（包含30ps量级）是非常重要的。在VLBI天休测量和测地计算的各种软件中，至今尚未计及射电源结构对延迟的影响。本文利用两子源模型对源结构延迟的大小及随时间的变化进行了计算，讨论了源结构延迟对VLBI天测和测地参数的影响，指出：（1）除对某些VLBI天测的射电源作长期的监测与研究，给出它们的双频综合图外，对大多数源可采用简单的两子源模型；（2）源结构对延迟的影响主要依赖于基线相对于源形态的主要特征的空间投影；（3）源结构延迟对天测和测地参数的影响达厘米和亚毫角秒量级。
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| 关 键 词： | VLBI天体测量 源结构延迟 源结构延迟的影响 |
The Effects of Radio Source Structures on VLBI Astrometry |
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| XIA Yi-fei,PENG Yun-lou.The Effects of Radio Source Structures on VLBI Astrometry[J].Journal of Time and Frequency,1998,21(1):54-58. |
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| Authors: | XIA Yi-fei PENG Yun-lou |
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| Abstract: | In this paper, the magnitude and variations of the delay corrections from the radiosources structute (i.e.structure correction)for a two-component model are calculated.and the effects of the structure corrections on the parameters in astrometry and genodesyare dicussed. It is shown that (1)apart from the long-term mornitoring and making the dual frequency maps for extragalactic radio source srructures,the simple two-component model is useful for most of the sources;(2)the structure corrections of radio sources main-ly depend on the orientation ofthe projection of the baseling relative to the main featruesof the source morphology in the sky;(3)the effects of the structure corrections on the pa-rameters in astrometry nad geodesy are of the orders of centimeter nad sub-milliarcsecond. |
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| Keywords: | VLBI Astrometry Delay Correction from Radio Source Structures Effects of Structures Correction |
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