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C Copyright 1981-2007 ECMWF
C
C Licensed under the GNU Lesser General Public License which
C incorporates the terms and conditions of version 3 of the GNU
C General Public License.
C See LICENSE and gpl-3.0.txt for details.
C
SUBROUTINE XYZ2LL(X,Y,Z,RLAT,RLONG,INROW)
C---->
C**** XYZ2LL
C
C Purpose
C -------
C
C Converts an array of (x,y,z) coordinates to an
C array of latitude/longitude values.
C
C
C Interface
C ---------
C
C CALL XYZ2LL(X,Y,Z,RLAT,RLONG,INROW)
C
C Input
C -----
C
C (X,Y,Z) - Array of coordinates.
C INROW - Count of coordinates.
C
C
C Output
C ------
C
C RLAT - Array of latitudes.
C RLONG - Array of corresponding longitudes.
C
C
C Method
C ------
C
C Z axis is the polar axis directed from south to north.
C X and Y axes are in the equatorial plane and have origin at the
C centre of the Earth. The X axis passes through (O north, 0 east).
C Longitude values are in range (0,360).
C
C
C Externals
C ---------
C
C None.
C
C
C Author
C ------
C
C J.D.Chambers ECMWF
C
C----<
C
IMPLICIT NONE
C
C Subroutine arguments
C
REAL X,Y,Z,RLAT,RLONG
DIMENSION X(*),Y(*),Z(*),RLAT(*),RLONG(*)
INTEGER INROW
C
C Local variables
C
REAL*8 FACTOR
DATA FACTOR/57.2957763671875/
INTEGER LOOP
C
DO LOOP = 1, INROW
RLAT(LOOP) = ASIN(Z(LOOP)) * FACTOR
ENDDO
C
DO LOOP = 1, INROW
IF( ABS(X(LOOP)).GT.0.0001 ) THEN
RLONG(LOOP) = ATAN2(Y(LOOP),X(LOOP)) * FACTOR
ELSE IF ( Y(LOOP).GT.0.0 ) THEN
RLONG(LOOP) = 90.0
ELSE
RLONG(LOOP) = -90.0
ENDIF
ENDDO
C
DO LOOP = 1, INROW
IF(RLONG(LOOP).LT.0.0) RLONG(LOOP) = RLONG(LOOP) + 360.0
ENDDO
C
RETURN
END
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