并置VLBI站的相对形变及其与全球解结果的比较  

Relative Deformation Rates between Collocated VLBI Stations and Results Comparisons with Global Solutions

作　　者：杨志根[1] M.Berube A.Searle 

机构地区：[1]中国科学院上海天文台 [2]Geodetic Survey Division Natural Resources Canada Ottawa Canada

出　　处：《天文学报》2005年第1期70-75,共6页Acta Astronomica Sinica

基　　金：中国科学院周家天文台二期创新研究资助项目

摘　　要：基于ITRF2000地球参考架的三维VLBI站速度矢量和NNR-NUVEL-1A地 球板块运动模型,采用观测的VLBI基线长变化率作为约束,估计和讨论了全球6个并置 VLBI站的局部或区域性地壳的相对形变,并与国际地球参考架ITRFs解和VLBI全球解 glb2003以及VTRF2003的结果进行了比较.结果表明日本Kashima与Kashim34VLBI 站之间,美国GREENBANK的NRAO20与NRAO85_3站之间可能存在每年约近4毫 米的相对垂直形变;WESTFORD与HAYSTACK二站间每年近2毫米的垂直形变率差 基本可得到肯定,KOKEE和KAUAI二站的垂直形变率约有每年1至3毫米的差.利用 如下方法能较可靠地检测出并置VLBI站间的局部或区域性的地壳垂直形变,改进ITRF 解的可能不足.Accurate determination of station positions and velocity vectors for the realization and maintenance of the International Terrestrial Reference Frame (ITRF) are among the contributions of global VLBI stations. ITRF solutions, such as ITRF2000, are combination solutions using different space geodetic techniques and could have potential 'inconsistencies' between different realizations. At present, the estimated average uncertainty on regularly observed baselines for VLBI determined baseline length change is better than ±1.0mm/yr. It is discussed results of the relative deformations between nearby stations in 6 global collocated VLBI sites based on the ITRF2000 and using the NNR-NUVEL-1A model to calculate the modeled horizontal motions. Comparisons of the results with those of the ITRFs solutions and VTRF2003 solution (Nothnagel, 2003) are addressed. The technique uses the observed baseline rates as constraints to quantify local/regional crustal deformations relative to the NUVEL-IA model solution and obtain the relative deformation rates between two closely spaced VLBI stations separated by a few hundred to few thousand meters, and determines improved deformations at a regional or local spatial scale, isolating the 'inconsistencies' from the TRF solutions. The approach is introduced and preliminary comparisons are made.

关 键 词：VLBI 垂直形变 ITRF2000 变率 地壳 地球板块 地球参考架 运动模型 基线 三维 

分 类 号：P315[天文地球—地震学] P228[天文地球—固体地球物理学]