Highlights of Astronomy, Volume 16 XXVIIIth IAU General Assembly, August 2012 T. Montmerle, ed. c  International Astronomical Union 2015 doi:10.1017/S1743921314005535 The IERS Conventions (2010): reference systems and new models B. Luzum 1 and G. Petit 2 † 1 Earth Orientation Department, U.S. Naval Observatory, Washington, DC 20392, USA 2 Bureau International des Poids et Mesures, S` evres, France Abstract. The IERS Conventions (2010) provides the international standard for models for use in the generation of celestial reference systems (CRS), terrestrial reference systems (TRS), and the Earth orientation parameters (EOPs) that relate the associated frames. Significant improvements over the previous IERS Conventions (2003) are outlined, and an overview of the latest adopted models and standards is shown. Finally, future plans for the Conventions are provided. Keywords. standards, reference systems, time, Earth orientation, astrometry 1. Introduction The IERS Conventions (2010) (Petit & Luzum 2010) is a set of constants, models, and algorithms, assembled and verified by subject matter experts, to be used in the analysis of Earth orientation and reference systems data. The Conventions strives to be internally consistent as well as consistent with IERS products including the ITRF and ICRF as well as the EOPs that link the two reference frames. Whenever possible, the Conventions are consistent with international standards. Because of the efforts to maintain internal and external consistency, implementation of the IERS Conventions in reduction and analysis software helps to minimize systematic errors in the resulting EOP and reference frame data. 2. Content The IERS Conventions (2010) contains the latest adopted models and standards. Top- ics included are numerical standards, reference systems, transformations between sys- tems, geopotential, displacement of reference points, tidal variations, atmospheric propa- gation delays, and relativistic models. The recommended models are reviewed continually, and suggested improvements are evaluated by an Advisory Board. Based on their rec- ommendation, modifications are made to the content of the IERS Conventions Updates and ultimately result in a new registered edition. 3. Improvements in IERS Conventions (2010) Several improvements were made to the IERS Conventions (2010). The most signif- icant changes to the Conventions came with the adoption of the ITRF2008 (Altamimi et al. 2011), ICRF2 (Fey et al. 2009), and the IAU2000/2006 precession-nutation model (Mathews et al. 2002, Capitaine et al. 2003). Additional improvements in modeling were † E-mail: brian.luzum@usno.navy.mil or gpetit@bipm.org 227 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1743921314005535 Downloaded from https://www.cambridge.org/core. IP address: 54.70.40.11, on 17 Aug 2019 at 22:30:18, subject to the Cambridge Core terms of use, available at