SUBROUTINE ORTHO_EOP ( TIME, EOP ) *+ * - - - - - - - - - - * O R T H O _ E O P * - - - - - - - - - - * * This routine is part of the International Earth Rotation and * Reference Systems Service (IERS) Conventions software collection. * * The purpose of the subroutine is to compute the diurnal and semi- * diurnal variations in Earth Orientation Parameters (x,y, UT1) from * ocean tides. * * In general, Class 1, 2, and 3 models represent physical effects that * act on geodetic parameters while canonical models provide lower-level * representations or basic computations that are used by Class 1, 2, or * 3 models. * * Status: Class 1 model * * Class 1 models are those recommended to be used a priori in the * reduction of raw space geodetic data in order to determine * geodetic parameter estimates. * Class 2 models are those that eliminate an observational * singularity and are purely conventional in nature. * Class 3 models are those that are not required as either Class * 1 or 2. * Canonical models are accepted as is and cannot be classified as a * Class 1, 2, or 3 model. * * Given: * TIME d Modified Julian Date * * Returned: * EOP d delta_x, in microarcseconds * delta_y, in microarcseconds * delta_UT1, in microseconds * * Notes: * * 1) The diurnal and semidiurnal orthoweights fit to the 8 constituents * are listed in Reference 1. * * Called: * CNMTX Compute time dependent part of second degree * diurnal and semidiurnal tidal potential from * the dominant spectral lines in the Cartwright- * Tayler-Edden harmonic decomposition * * Test case: * given input: MJD = 47100D0 * * expected output: delta_x = -162.8386373279636530D0 microarcseconds * delta_y = 117.7907525842668974D0 microarcseconds * delta_UT1 = -23.39092370609808214D0 microseconds * * References: * * Ray, R. D., Steinberg, D. J., Chao, B. F., and Cartwright, D. E., * "Diurnal and Semidiurnal Variations in the Earth's Rotation * Rate Induced by Ocean Tides", 1994, Science, 264, pp. 830-832 * * Petit, G. and Luzum, B. (eds.), IERS Conventions (2010), * IERS Technical Note No. 36, BKG (2010) * * Revisions: * 1997 February R. Eanes Original code * 2008 November 07 B.E. Stetzler Added header and copyright * 2008 November 07 B.E. Stetzler Provided test case * 2009 May 12 B.E. Stetzler Replaced ENDDO statements with * CONTINUE statements * 2009 June 09 B.E. Stetzler Updated validated test case values * based on changes to CNMTX.F * 2010 March 19 B.E. Stetzler Capitalized variables for FORTRAN * 77 backwards compatibility *----------------------------------------------------------------------- IMPLICIT NONE INTEGER K, J DOUBLE PRECISION EOP(3), ORTHOW(12,3), TIME, H(12) DATA ORTHOW / .-6.77832D0,-14.86323D0,0.47884D0,-1.45303D0,0.16406D0, 0.42030D0, . 0.09398D0,25.73054D0,-4.77974D0, 0.28080D0,1.94539D0, -0.73089D0, .14.86283D0,-6.77846D0, 1.45234D0, 0.47888D0,-0.42056D0, 0.16469D0, .15.30276D0,-4.30615D0, 0.07564D0, 2.28321D0,-0.45717D0,-1.62010D0, .-1.76335D0,1.03364D0, -0.27553D0, 0.34569D0,-0.12343D0,-0.10146D0, .-0.47119D0,1.28997D0, -0.19336D0, 0.02724D0, 0.08955D0, 0.04726D0/ * Compute the partials of the tidal variations to the orthoweights CALL CNMTX (TIME, H) * Compute eop changes DO 20 K=1,3 EOP(K) = 0D0 DO 40 J=1,12 EOP(K) = EOP(K) + H(J)*ORTHOW(J,K) 40 CONTINUE 20 CONTINUE RETURN * Finished. *+---------------------------------------------------------------------- * * Copyright (C) 2008 * IERS Conventions Center * * ================================== * IERS Conventions Software License * ================================== * * NOTICE TO USER: * * BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS * WHICH APPLY TO ITS USE. * * 1. The Software is provided by the IERS Conventions Center ("the * Center"). * * 2. Permission is granted to anyone to use the Software for any * purpose, including commercial applications, free of charge, * subject to the conditions and restrictions listed below. * * 3. 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In any published work produced by the user and which includes * results achieved by using the Software, you shall acknowledge * that the Software was used in obtaining those results. * * 5. The Software is provided to the user "as is" and the Center makes * no warranty as to its use or performance. The Center does not * and cannot warrant the performance or results which the user may * obtain by using the Software. The Center makes no warranties, * express or implied, as to non-infringement of third party rights, * merchantability, or fitness for any particular purpose. In no * event will the Center be liable to the user for any consequential, * incidental, or special damages, including any lost profits or lost * savings, even if a Center representative has been advised of such * damages, or for any claim by any third party. * * Correspondence concerning IERS Conventions software should be * addressed as follows: * * Gerard Petit * Internet email: gpetit[at]bipm.org * Postal address: IERS Conventions Center * Time, frequency and gravimetry section, BIPM * Pavillon de Breteuil * 92312 Sevres FRANCE * * or * * Brian Luzum * Internet email: brian.luzum[at]usno.navy.mil * Postal address: IERS Conventions Center * Earth Orientation Department * 3450 Massachusetts Ave, NW * Washington, DC 20392 * * *----------------------------------------------------------------------- END