Earthtide               Earthtide class
calc_earthtide          earthtide
earthtide-package       earthtide: R port of the earth tide processing
                        package ETERNA (by Hans-Georg Wenzel) including
                        the Kudryavtsev wave catalog.
eterna_wavegroups       Hartmann and Wenzel (1995) (ETERNA 3.4)
                        wavegroups
get_iers                get_iers
get_main_frequency      get_main_frequency
