SUBROUTINE sla_PREBN (BEP0, BEP1, RMATP) *+ * - - - - - - * P R E B N * - - - - - - * * Generate the matrix of precession between two epochs, * using the old, pre-IAU1976, Bessel-Newcomb model, using * Kinoshita's formulation (double precision) * * Given: * BEP0 dp beginning Besselian epoch * BEP1 dp ending Besselian epoch * * Returned: * RMATP dp(3,3) precession matrix * * The matrix is in the sense V(BEP1) = RMATP * V(BEP0) * * Reference: * Kinoshita, H. (1975) 'Formulas for precession', SAO Special * Report No. 364, Smithsonian Institution Astrophysical * Observatory, Cambridge, Massachusetts. * * Called: sla_DEULER * * P.T.Wallace Starlink 23 August 1996 * * Copyright (C) 1996 Rutherford Appleton Laboratory *- IMPLICIT NONE DOUBLE PRECISION BEP0,BEP1,RMATP(3,3) * Arc seconds to radians DOUBLE PRECISION AS2R PARAMETER (AS2R=0.484813681109535994D-5) DOUBLE PRECISION BIGT,T,TAS2R,W,ZETA,Z,THETA * Interval between basic epoch B1850.0 and beginning epoch in TC BIGT = (BEP0-1850D0)/100D0 * Interval over which precession required, in tropical centuries T = (BEP1-BEP0)/100D0 * Euler angles TAS2R = T*AS2R W = 2303.5548D0+(1.39720D0+0.000059D0*BIGT)*BIGT ZETA = (W+(0.30242D0-0.000269D0*BIGT+0.017996D0*T)*T)*TAS2R Z = (W+(1.09478D0+0.000387D0*BIGT+0.018324D0*T)*T)*TAS2R THETA = (2005.1125D0+(-0.85294D0-0.000365D0*BIGT)*BIGT+ : (-0.42647D0-0.000365D0*BIGT-0.041802D0*T)*T)*TAS2R * Rotation matrix CALL sla_DEULER('ZYZ',-ZETA,THETA,-Z,RMATP) END