Welcome to the IERS Conventions website

The primary product of the Center is the IERS Conventions. The IERS Conventions describes the reference systems realized by the IERS, in addition to developing and maintaining the models and procedures used to support this endeavor.

The Conventions are in book-form, published on our website and the IERS website as a PDF. Updated versions are published every several years when a sufficient volume of material requires updating. The latest version is the IERS Conventions (2010), published as Technical Note 36. It can also be downloaded on our website as a tarball.