Table of contents
IRFTRN ( Inertial reference frame transformation )
SUBROUTINE IRFTRN ( REFA, REFB, ROTAB )
Return the matrix that transforms vectors from one specified
inertial reference frame to another.
DOUBLE PRECISION ROTAB ( 3, 3 )
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
REFA I Name of reference frame to transform vectors FROM.
REFB I Name of reference frame to transform vectors TO.
ROTAB O REFA-to-REFB transformation matrix.
REFB are the names of two inertial reference frames. Any names
accepted by the routine IRFNUM may be used. See
$Particulars for a list of some of the more commonly used
inertial reference frame names.
ROTAB is a rotation matrix that transforms the
coordinates of a vector V relative to the
reference frame specified by REFA to the
coordinates of V relative to the reference frame
specified by REFB. The transformation is carried
out by the matrix multiplication
V = ROTAB * V.
1) If either of the input reference frame names is invalid, an
error is signaled by a routine in the call tree of this
Normally applications should call the more general, higher level
routine PXFORM instead of this routine.
This routine is a macro that replaces the code fragment
CALL IRFNUM ( REFA, CODEA )
CALL IRFNUM ( REFB, CODEB )
CALL IRFROT ( CODEA, CODEB, ROTAB )
Among the reference frame names accepted by IRFNUM are:
See the SPICELIB routine GHGIRF for details.
1) Transform a vector V1950 from the B1950 to the J2000
C Ask IRFTRN for the matrix that transforms vectors
C from the B1950 to the J2000 reference frame.
CALL IRFTRN ( 'B1950', 'J2000', TRANS )
C Now transform V1950 to the J2000 reference frame.
CALL MXV ( TRANS, V1950, V2000 )
N.J. Bachman (JPL)
J. Diaz del Rio (ODC Space)
W.L. Taber (JPL)
SPICELIB Version 1.1.0, 20-AUG-2021 (JDR)
Added IMPLICIT NONE statement.
Edited the header to comply with NAIF standard.
SPICELIB Version 1.0.2, 28-SEP-2004 (NJB)
Corrected comment in code example in header. Made other minor
updates to header.
SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)
Comment section for permuted index source lines was added
following the header.
SPICELIB Version 1.0.0, 30-AUG-1991 (NJB)