Implementing the IAU 2000 resolutions in almanacs by J.A. Bangert (Astronomical Applications Department, U.S. Naval Observatory)
Almanacs provide practical astronomical data in an accessible form to satisfy the needs of a wide variety of user applications such as navigation, pointing a telescope, planning an observing session, or scientific research. Many users expect that the general content and format of the almanacs will remain the same from year to year. Thus, changes to the almanacs are made as infrequently as possible, and only after careful deliberation. The almanac makers implement a proposed change when the change (1) will result in more accurate information in the almanac, (2) is based on sound scientific underpinnings, and (3) will result in data or information relevant to the users of the almanac. The last criterion is the most important. The IAU 2000 resolutions must be considered in the context of these criteria before they are implemented in the almanacs. In addition, even under ideal circumstances there is a considerable lag between the time a resolution is adopted and the time that it is implemented in the almanacs. This lag is due to the time needed to develop, implement, and test new production software, and to the normal almanac publication schedule.
Changes in the Astronomical Almanac by G. H. Kaplan (Astronomical Applications Department, U.S. Naval Observatory)
The Astronomical Almanac must satisfy the needs of a variety of users around the world, who represent a wide range of interests and sophistication levels. The book, prepared jointly by the US and UK nautical almanac offices, is based to the greatest extent possible on IAU-endorsed and other internationally recognized standards. The IAU resolutions on reference systems and Earth rotation adopted in 1997 and 2000 represent a significant change in approach for both subject areas. To implement these resolutions in contents of The Astronomical Almanac, both the reference data and algorithms used must be changed, and some new tabulations added. Some of the required modifications have already been made and others will be introduced into the editions now in preparation. The specific changes are described, along with issues for the future.
Implementation of the IAU resolutions in the French ephemerides by W. Thuillot (IMCCE, Observatoire de Paris, France)
Institut de mécanique céleste et de calcul des éphémérides (IMCCE), formerly Service des calculs et de mécanique céleste du Bureau des longitudes, is in charge, at Paris Observatory and under the auspices of Bureau des longitudes, of the making and the diffusion of the French ephemerides. Various ephemerides are provided as well by means of books as by means of on-line electronic facilities. The implementation of the IAU resolutions, together with the introduction of new dynamical models that we project, will then require important efforts. It appears that the improved models and the new constants must be adopted, therefore the use of new models of precession and nutation will be done at first. On the other hand, the changes in the systems of coordinates which will imply too hard disruptions to the general users will only be introduced in parallel with the usual systems.
Revisions of Japanese Almanacs by T. Fukushima (National Astronomical Observatory of Japan)
Japan publishes two kinds of national almanacs; the more precise and comprehensive one for the nautical use, the Japanese Ephemeris (JE) by the Maritime Safety Agency (MSA), and the more compact for the civil use, the Ephemeris Year Book (EYB) by the National Astronomical Observatory of Japan (NAOJ). As for JE, it is still in the same style and the same contents since the last major revision in 1984. The MSA will make no revision of the JE until all the required procedures for the changes are clear. As for EYB, we have already done a major revision from the edition of Year 2003. The contents of the revisions are (1) the change of base planetary/lunar ephemeris from DE200 to DE405, (2) the change of nutation theory from IAU 1980 to Shirai and Fukushima (2001), and (3) the change of geodetic datum from Tokyo datum to the new Tokyo datum, being almost the same as the latest ITRF.
The Russian astronomical yearbooks: modern state and IAU resolutions by M.L. Sveshnikov, N.I. Glebova, M.V. Lukashova, A.A. Malkov (Institute of Applied astronomy, RAS, St.-Petersburg, Russia)
IAA RAS produces several printed yearbooks. Their structure and contents are changed regularity to satisfy IAU resolutions and requirements of users. The current plan of implementing the IAU 2000 resolutions in Russian yearbooks is given. Future reform of yearbooks includes the replacement of planetary ephemeredes, precession-nutation model, stellar catalogue and transfer to the new CEO concept. It will be carried out during 2003-2006.
