Astronomical Almanac
The Astronomical Almanac is compiled and published by the Institute of Geodesy and Cartography in Warsaw, annually since 1946, since 2002 also in pdf, and as of 2015 in part version "on-line".
The Yearbook is the source of data used in the astro-geodetical measurements, and the source of up-to-date information about the latest systems and reference frames adopted by the International Astronomical Union and the International Union of Geodesy and Geophysics. It is also the source of many astronomical data used in teaching astronomy and geodesy, and by amateurs.
