ITRF2005: A new release of the International Terrestrial Reference Frame based on time series of station positions and earth orientation parameters
ITRF2005: A new release of the International Terrestrial Reference Frame based on time series of station positions and earth orientation parameters
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DOI：
10.1029/2007jb004949
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发表时间：
2007-09-07
影响因子：
3.9
通讯作者：
Boucher, C.
中科院分区：
文献类型：
--
作者：
Altamimi, Z.;Collilieux, X.;Boucher, C.
与过去结合了全球长期解决方案的国际地球参考框架(ITRF)版本不同，ITRF2005使用站点位置和每日地球方位参数(EOPs)的时间序列作为输入数据(每周使用卫星技术，24小时使用甚长基线干涉测量)。利用站点位置时间序列的优点是可以监测站点的非线性运动和不连续性，并检查帧物理参数(即原点和尺度)的时间行为。ITRF2005原点的定义是，它相对于地球质心的平移量和平移率为零，由卫星激光测距(SLR)跨越13年的观测时间序列平均得出。它的规模是通过取消该规模及其相对于跨越26年观测的甚长基线干涉测量(VLBI)时间序列的比率来确定的。2005年国际大地测量框架的方位(在历元2000.0)及其速率与国际大地测量框架2000的方向一致，使用了70个高质量的大地测量站。估计ITRF2005年的原点(在纪元2000.0)及其相对于ITRF2000的速率沿X、Y和Z轴的一致性水平分别为0.10、0.80、5.8毫米和0.2、0.1、1.8毫米/年。我们估计这些部件的形式误差分别为0.3 mm和0.3 mm/年。我们认为，这两个帧来源之间的低水平一致性很可能是由于SLR网络几何结构较差以及它随着时间的推移而退化。2005年关于84个共址地点的ITRF2005年组合显示，在历元2000.0，SLR和VLBI长期解决方案之间的尺度不一致性为1 ppb(赤道6.3毫米)，而通过堆叠各自的时间序列获得的SLR和VLBI长期解决方案之间的尺度不一致为0.08ppb/年。这种不一致的可能原因可能包括较差的SLR和VLBI网络及其共址、局部联系的不确定性、系统效应以及在这两种技术的数据分析中使用的可能不一致的模型校正。在ITRF历史上，ITRF2005的严格组合第一次提供了自洽的EOPs系列，包括VLBI和卫星技术的极地运动以及VLBI的世界时间和日长。用152个测点的速度场估算了15个构造板块的绝对自转极点，与ITRF2005框架一致，误差小于1.5 mm/年。这一新的绝对板块运动模型取代并显著改进了ITRF2000涉及六个主要构造板块的模型。
Unlike the past International Terrestrial Reference Frame (ITRF) versions where global long-term solutions were combined, the ITRF2005 uses as input data time series ( weekly from satellite techniques and 24-h session-wise from Very Long Baseline Interferometry) of station positions and daily Earth Orientation Parameters (EOPs). The advantage of using time series of station positions is that it allows to monitor station non-linear motion and discontinuities and to examine the temporal behavior of the frame physical parameters, namely the origin and the scale. The ITRF2005 origin is defined in such a way that it has zero translations and translation rates with respect to the Earth center of mass, averaged by the Satellite Laser Ranging (SLR) time series spanning 13 years of observations. Its scale is defined by nullifying the scale and its rate with respect to the Very Long Baseline Interferometry (VLBI) time series spanning 26 years of observations. The ITRF2005 orientation (at epoch 2000.0) and its rate are aligned to the ITRF2000 using 70 stations of high geodetic quality. The estimated level of consistency of the ITRF2005 origin ( at epoch 2000.0) and its rate with respect to the ITRF2000 is respectively 0.1, 0.8, 5.8 mm and 0.2, 0.1, 1.8 mm/yr along the X, Y and Z-axis. We estimate the formal errors on these components to be 0.3 mm and 0.3 mm/yr. We believe that this low level of agreement between the two frame origins is most probably due to the poor SLR network geometry and its degradation over time. The ITRF2005 combination involving 84 co-location sites revealed a scale inconsistency of 1 ppb ( 6.3 mm at the equator), at epoch 2000.0, and 0.08 ppb/yr between the SLR and VLBI long-term solutions as obtained by the stacking of their respective time series. Possible causes of this inconsistency may include the poor SLR and VLBI networks and their co-locations, local tie uncertainties, systematic effects and possible inconsistent model corrections used in the data analysis of both techniques. For the first time of the ITRF history, the ITRF2005 rigorous combination provides self-consistent series of EOPs, including Polar Motion from VLBI and satellite techniques and Universal Time and Length of Day from VLBI only. A velocity field of 152 sites with an error less than 1.5 mm/yr is used to estimate absolute rotation poles of 15 tectonic plates that are consistent with the ITRF2005 frame. This new absolute plate motion model supersedes and significantly improves that of the ITRF2000 which involved six major tectonic plates.