   This tide model is an update of that described by E Schrama and R Ray
in Journal of Geophysical Research, v.99, p 24799, 1994.  This version (950308)
is based on cycles 9-71 of Topex + Poseidon.  The model was computed as
corrections to the ocean-tide model of Le Provost et al (1994) plus the
load-tide model of Cartwright & Ray (1991).  Five constituents (O1,K1,N2,M2,S2)
were determined.  We also give supplementary Q1,P1,K2 files that are
directly from Le Provost's model. (We thank him for allowing us to use
these 3 tides.)  Although the model was computed using the GDR-based orbits,
we applied a semi-analytical correction to account for the (JGM3-GDR) tidal
orbital differences; this correction was provided by S Bettadpur & R Eanes,
whom we also thank.
   Two sets of tidal grids are provided.  One set is for the ocean tide only,
the other for the ocean+load tide.  The latter should be used for computing
corrections to altimetry.  The prediction software runs on either set of
constituent grids; the software assumes the user is using the 8 tides listed
above, or some subset of them.
   A small routine written several years ago by D Cartwright is also provided
for computing equilibrium long-period tides.

E J O Schrama     R D Ray      15 March 1995

