The Phase Variations of Retrograde Free Core Nutation
Measuring the Future: Proceedings of the Fifth IVS General Meeting, A. Finkelstein and D. Beherend (eds), St. Petersburg, Nauka, 231-235. (2008)Full text
The application of an envelope method to the analysis of celestial pole offsets in the interval 1984—2007, published by IERS and NEOS services, has shown that the mean value of the RFCN period is close to —444 solar days. However there are three consecutive intervals of time when this period sharply changed and had values —421.4+-0.1, —614.7+-1.1, and —447.1+-0.2 days.