C     ****
C     ****     /TRIG/ FOR TRIGONOMETRIC FACTORS NEEDED IN THE
C     ****       CALCULATION OF THE DERIVATIVES OF THE GEOMAGNETIC
C     ****       COORDINATES W.R.T. THE GEOGRAPHIC COORDINATES
C     ****
      real :: cslatm,snlatm,cslonm,snlonm,cslatg,snlatg,cslong,snlong
      COMMON/TRIG/CSLATM(ZIMXP1,ZJMX),SNLATM(ZIMXP1,ZJMX),
     1  CSLONM(ZIMXP1,ZJMX),SNLONM(ZIMXP1,ZJMX),CSLATG(ZJMX),
     2  SNLATG(ZJMX),CSLONG(ZIMXP1),SNLONG(ZIMXP1)
C     ****
C     ****     WHERE:
C     ****       ZIMX=72, ZJMX=36, ZIMXP1=ZIMX+1
C     ****       CSLATM = COS(THETAS)
C     ****       SNLATM = SIN(THETAS)
C     ****       CSLONM = COS(LAMDAS)
C     ****       SNLONM = SIN(LAMDAS)
C     ****       CSLATG = COS(THETA)
C     ****       SNLATG = SIN(THETA)
C     ****       CSLONG = COS(LAMDA)
C     ****       SNLONG = SIN(LAMDA)
C     ****
C