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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 LL2XYZ(RLAT,RLONG,X,Y,Z,INROW)
C---->
C**** LL2XYZ
C
C Purpose
C -------
C
C Converts an array of latitude/longitude values to an
C array of (x,y,z) coordinates.
C
C
C Interface
C ---------
C
C CALL LL2XYZ(RLAT,RLONG,X,Y,Z,INROW)
C
C Input
C -----
C
C RLAT - Array of latitudes.
C RLONG - Array of corresponding longitudes.
C INROW - Count of latitudes/longitudes.
C
C
C Output
C ------
C
C (X,Y,Z) - Array of coordinates.
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
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 RLAT,RLONG,X,Y,Z
DIMENSION RLONG(*),X(*),Y(*),Z(*)
INTEGER INROW
C
C Parameters
C
INTEGER JPMAXGG
PARAMETER( JPMAXGG = 1280 )
C
C Local variables
C
REAL FACTOR, COS_LAT, SIN_LAT, COS_LON, SIN_LON
DIMENSION COS_LON(JPMAXGG), SIN_LON(JPMAXGG)
DATA FACTOR/0.017453293/
INTEGER LOOP
REAL ALAT
C
ALAT = RLAT * FACTOR
COS_LAT = COS(ALAT)
SIN_LAT = SIN(ALAT)
C
DO LOOP = 1, INROW
COS_LON(LOOP) = COS(RLONG(LOOP)*FACTOR)
SIN_LON(LOOP) = SIN(RLONG(LOOP)*FACTOR)
C
X(LOOP) = COS_LAT*COS_LON(LOOP)
Y(LOOP) = COS_LAT*SIN_LON(LOOP)
Z(LOOP) = SIN_LAT
ENDDO
C
RETURN
END
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