An other look at non-rotating origins by G. H. Kaplan (Astronomical Applications Department, U.S. Naval Observatory)
As an alternative to the usual quantities used for positioning the CEO, a simple vector differential equation for the position of a non-rotating origin on its reference sphere is developed. The equation can be easily numerically integrated to high precision. This scheme directly yields the ICRS right ascension and declination of the CEO, or the ITRF longitude and latitude of the TEO, as a function of time. This simplifies the derivation of the main transformation matrix between the ITRF and the ICRS. This approach also yields a simple vector expression for apparent sidereal time. The directness of the development may have pedagogical and pratical advantages for the vast majority of astronomers who are unfamiliar with the history of this topic.
FAQS as an educational device by C. Ma (GSFC, USA)
FAQs have become common on the worldwide web as an introduction to a specific topic. An initial set of FAQs on the recent IAU resolutions has been prepared for linking from relevant web sites. The content, future refinement and expansion, and distribution is discussed.
