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IAU C.A3 Fundamental Standards will serve as the primary point of contact between Division A and the user community regarding standards for fundamental astronomy. This involves:

  1. producing robust standards, and ensuring that new standards are readily understood by both the astronomical and broader scientific communities; i.e., are relevant and "fit for purpose";
  2. ensuring that the associated nomenclature is well defined and understood; encouraging future research, particularly groups with the appropriate expertise, to improve their models and help them to develop relevant standards;
  3. implementing good practices in setting and using IAU standards, including identifying requirements for new standards; providing a link between the users of fundamental standards and developers to (1) inform users of current standards and the status of those under development, and (2) to accept input from the broader user community in order to ensure that standards are relevant for practical needs; and
  4. encouraging interest among young astronomers in developing the field of astronomical standards and services for the scientific community.


There are continuing requirements within both the astronomical community and other scientific and engineering communities for standard data and models involving the concepts of fundamental astronomy. These standards are incorporated into products and services (e.g., publications, data services, software, websites; hereafter, "services"), many of which are provided under the auspices of governments, national/international agencies, and institutes. The services want to be able to ensure their broad user community that the standards they use are produced with the authority of the relevant "professional body", the IAU. Fostering communication between those developing the standards of fundamental astronomy and those applying them has clear and obvious benefits. Such communication ensures that the user community is aware of the most appropriate standards, while the developers are made aware of emerging requirements for new or updated standards.

An important role will be the cooperation with various groups within the IAU to provide not only state-of-the-art services, but also to develop standards and services designed to meet their emerging needs. Such groups include Division A Standards of Fundamental Astronomy (SOFA), Division A Working Group (WG) on Numerical Standards of Fundamental Astronomy (WGNSFA), Division F/A WG on Cartographic Coordinates & Rotational Elements (WGCCRE), and other IAU groups such as producers of solar system ephemerides. SOFA, the WGNSFA and the WGCCRE (all long-term WGs) already play an important role in developing and promulgating IAU standards, via software and numerical data.

An equally important role for FS will be formal coordination with groups that provide services under the joint auspices of the IAU and other scientific organisations such as the joint IAU/IUGG International Earth Rotation and Reference Systems Service (IERS), the International Association of Geodesy's (IAG) Global Geodetic Observing System (GGOS) Bureau for Standards & Conventions (who have provided a formal supporting letter), and the International VLBI Service (IVS) for Geodesy and Astrometry.

Another vital role for the Commission is the formal and informal connections with external scientific organizations such as the Committee on Space Research (COSPAR) and the Consultative Committee on Time and Frequency (CCTF) of the International Congress of Weights and Measures.

Fundamental standards are used by astronomers in many astronomical sub-fields that cross Division lines. In addition, the FS will provide IAU-endorsed services and expertise to a broad community of scientists-inside and outside astronomy-and engineers. It will encourage membership of interested scientists, especially IAU members and associates, and also seek input from space-science investigators, aerospace engineers, geodesists, and geophysicists. It is expected that working groups designed to develop specialized standards and services would be established similar to some of the existing working groups of Division A (i.e. SOFA and the WGNSFA).

Last modified: 2020 April