Analysis of Astrometric Position Time Series for ICRF-2
Abstract
A second realization of the International Celestial Reference Frame, ICRF-2, is currently underway with a projected completion date concurrent with the 2009 IAU General Assembly. This work is being carried out by two working groups: the IERS/IVS Working Group will generate ICRF-2 from VLBI observations of extragalactic radio sources, consistent with the current realization of the ITRF and EOP data products and the IAU working group will oversee the generation of ICRF-2. Of primary importance to this work is the selection of a set of defining sources to be used to orient the ICRF-2 axes. These sources should be as positionally stable as can be determined with existing data and analysis. It is well known that compact extragalactic sources have variable and unpredictable emission structures on scales larger than the accuracy of their position estimates. Temporal variations of the intrinsic structure of these objects results in apparent motion when astrometric observations are made at several epochs. Generation and analysis of position time series is one method to address this issue. Here we compare two methods for generation of position time series.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2007
- Accession Number
- ADA483860
Entities
People
- A. L. Fey
- D. A. Boboltz
Organizations
- United States Naval Observatory