Accuracy of the International Terrestrial Reference Frame origin and Earth expansion
Article first published online: 8 JUL 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 13, July 2011
How to Cite
2011), Accuracy of the International Terrestrial Reference Frame origin and Earth expansion, Geophys. Res. Lett., 38, L13304, doi:10.1029/2011GL047450., , , , , and (
- Issue published online: 8 JUL 2011
- Article first published online: 8 JUL 2011
- Manuscript Accepted: 23 MAY 2011
- Manuscript Revised: 22 MAY 2011
- Manuscript Received: 11 MAR 2011
- geocenter motion;
- solid Earth expansion;
- terrestrial reference frames
 The International Terrestrial Reference Frame (ITRF) is a fundamental datum for high-precision orbit tracking, navigation, and global change monitoring. Accurately realizing and maintaining ITRF origin at the mean Earth system center of mass (CM) is critical to surface and spacecraft based geodetic measurements including those of sea level rise and its sources. Although ITRF combines data from satellite laser ranging (SLR), Very Long Baseline Interferometry (VLBI), Global Positioning System (GPS), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), its origin is currently realized by the single technique of SLR. Consequently, it is difficult to independently evaluate the origin accuracy. Also, whether the solid Earth is expanding or shrinking has attracted persistent attention. The expansion rate, if any, has not been accurately determined before, due to insufficient data coverage on the Earth's surface and the presence of other geophysical processes. Here, we use multiple precise geodetic data sets and a simultaneous global estimation platform to determine that the ITRF2008 origin is consistent with the mean CM at the level of 0.5 mm yr−1, and the mean radius of the Earth is not changing to within 1σ measurement uncertainty of 0.2 mm yr−1.