C
C COMPUTE THE MATRICES FOR TRANSFORMATION FROM THE EARTH MEAN ECLIPTIC AND 
C EQUINOX OF 1950 (EME'50) COORDINATES TO PLANETARY SPHERICAL COORDINATES.
C
C MODIFIED TO SWAP VALUES OF LATITUDE AND LONGITUDE BEFORE RETURN 
C 07/31/95 SBK
C
      SUBROUTINE SEDRENC(GMT,NAV,PV,RJVE,ANG,S,ROT,Q,RANGE)
C
C NAV - Navigation record of either 126 or 252 word length.
C
C PV - Pointing vector data from words 12-20 of original MVS pointing
C      vector block.  
C         PV(1,1) = PITCH X COMPONENT
C         PV(2,1) = PITCH Y COMPONENT
C         PV(3,1) = PITCH Z COMPONENT
C         PV(1,2) = YAW X COMPONENT
C         PV(2,2) = YAW Y COMPONENT
C         PV(3,2) = YAW Z COMPONENT
C         PV(1,3) = ROLL X COMPONENT
C         PV(2,3) = ROLL Y COMPONENT
C         PV(3,3) = ROLL Z COMPONENT
C
C RJVE - Spacecraft range and velocity in planetary coordinates
C
      INTEGER*2 GMT(6)
C
      REAL*4 NAV(252),RJVE(6),ANG(2),PV(3,3),Q(3,3),ROT(3,3),S(3,3)
C
      REAL*8 DAYS,LONG,DRANGE,RA
C
C P-MATRICES TRANSFORM FROM CATERSIAN COMPONENTS REFERRED TO BY THE
C EARTH MEAN ECLIPTIC AND EQUINOX OF 1950 (EME'50) SYSTEM TO A 
C PLANETOCENTRIC CARTESIAN VERNAL EQUINOX SYSTEM (INERTIAL).
C
      REAL*4 PJ(3,3) / -7.214966E-1, +6.922823E-1, +1.370326E-2,
     &                 -6.922676E-1, -7.207863E-1, -3.511083E-2,
     &                 -1.442949E-2, -3.481867E-2, +9.992895E-1 /
C
      REAL*4 PS(3,3) / +9.915140E-1, -1.244780E-1, -3.749200E-2,
     &                 +9.252900E-2, +8.783090E-1, -4.690540E-1,
     &                 +9.131600E-2, +4.616040E-1, +8.823730E-1 /
C
      REAL*4 PU(3,3) / +9.737952E-1, -2.270260E-1, -1.349334E-2,
     &                 -4.308389E-2, -1.258954E-1, -9.911075E-1,
     &                 +2.233085E-1, +9.657171E-1, -1.323775E-1 /
C
      REAL*4 PN(3,3) / -7.093737E-1, -7.041542E-1, +3.091500E-2,
     &                 +6.092710E-1, -6.346587E-1, -4.753915E-1,
     &                 +3.543694E-1, -3.183947E-1, +8.792310E-1 / 
C
      REAL*4 ARADJ/71372.0E0/, ARADS/60330.0E0/, ARADU/25600.E0/,
     &       ARADN/24765.0E0/, DTR/0.17453293E0/
C
      INCLUDE 'UNPACK.INC'
C 
      IF ( ICOORD.EQ.4 ) THEN
C
C JUPITER
C
       DO I=1,3
        DO J=1,3
         Q(J,I) = PJ(1,I)*PV(1,J) + PJ(2,I)*PV(2,J) + PJ(3,I)*PV(3,J)
        END DO
        RJVE(I) = 
     &   (PJ(1,I)*NAV(19) + PJ(2,I)*NAV(20) + PJ(3,I)*NAV(21))/ARADJ
        RJVE(I+3) = 
     &   (PJ(1,I)*NAV(22) + PJ(2,I)*NAV(23) + PJ(3,I)*NAV(24))/ARADJ
       END DO
       ANG(1) = NAV(157)
       ANG(2) = NAV(159)
       RANGE = NAV(176)/ARADJ
C
      ELSE IF ( ICOORD.EQ.3 ) THEN
C
C SATURN
C
       DO I=1,3
        DO J=1,3
         Q(J,I) = PS(1,I)*PV(1,J) + PS(2,I)*PV(2,J) + PS(3,I)*PV(3,J)
        END DO
        RJVE(I) = 
     &   (PS(1,I)*NAV(19) + PS(2,I)*NAV(20) + PS(3,I)*NAV(21))/ARADS
        RJVE(I+3) = 
     &   (PS(1,I)*NAV(22) + PS(2,I)*NAV(23) + PS(3,I)*NAV(24))/ARADS
       END DO
       ANG(1) = NAV(76)
       ANG(2) = NAV(77) ! NEED TO SEE ORIGINAL CODE
       DAYS = GMT(2) - 1.0D0 + (GMT(3) + (GMT(4) + (GMT(5) +
     &        GMT(6)/1000.0D0)/60.0D0)/60.0D0)/24.0D0
       IF ( GMT(1).EQ.1981 ) DAYS = DAYS + 366.0D0
       DRANGE = DBLE(NAV(83))
       RA = NAV(103)
       LONG = 810.76D0*(DAYS - 3.860695545D-11*DRANGE) - RA
       ANG(2) = DMOD(LONG,360.D0)
       RANGE = NAV(83)/ARADS
C
      ELSE IF ( ICOORD.EQ.5 ) THEN
C
C URANUS
C
       DO I=1,3
        DO J=1,3
         Q(J,I) = PU(1,I)*PV(1,J) + PU(2,I)*PV(2,J) + PU(3,I)*PV(3,J)
        END DO
        RJVE(I) = 
     &   (PU(1,I)*NAV(19) + PU(2,I)*NAV(20) + PU(3,I)*NAV(21))/ARADU
        RJVE(I+3) = 
     &   (PU(1,I)*NAV(22) + PU(2,I)*NAV(23) + PU(3,I)*NAV(24))/ARADU
       END DO
       ANG(1) = NAV(139)
       ANG(2) = NAV(140)
       RANGE = NAV(153)/ARADU
C
      ELSE IF ( ICOORD.EQ.6 ) THEN
C
C NEPTUNE
C
       DO I=1,3
        DO J=1,3
         Q(J,I) = PN(1,I)*PV(1,J) + PN(2,I)*PV(2,J) + PN(3,I)*PV(3,J)
        END DO
        RJVE(I) = 
     &   (PN(1,I)*NAV(19) + PN(2,I)*NAV(20) + PN(3,I)*NAV(21))/ARADN
        RJVE(I+3) = 
     &   (PN(1,I)*NAV(22) + PN(2,I)*NAV(23) + PN(3,I)*NAV(24))/ARADN
       END DO
       ANG(1) = NAV(139)
       ANG(2) = NAV(140)
       RANGE = NAV(153)/ARADN
C
      END IF
C 
C COMPUTE PSI AND OMEGA
C
      SQ = SQRT(RJVE(1)**2+RJVE(2)**2+RJVE(3)**2)
      IF ( SQ.NE.0.0 ) THEN
       PSI = ACOS(RJVE(3)/SQ)
      ELSE
       PSI = 0.0
      END IF
      OMG = ATAN2(RJVE(2),RJVE(1))
C
C COMPUTES SINES AND COSINES OF ANGLES PSI AND OMEGA
C
      CPSI = COS(PSI)
      SPSI = SIN(PSI)
      COMG = COS(OMG)
      SOMG = SIN(OMG)
C
C COMPUTE S  MATRIX
C          1
C
      S(1,1) = SPSI*COMG
      S(1,2) = CPSI*COMG
      S(1,3) = -SOMG
      S(2,1) = SPSI*SOMG
      S(2,2) = CPSI*SOMG
      S(2,3) = COMG
      S(3,1) = CPSI
      S(3,2) = -SPSI
      S(3,3) = 0.0
C
C                             T
C COMPUTE ROTATION MATRIX S PA
C                          1
C
      DO I = 1,3
       DO J = 1,3
        ROT(J,I) = S(1,I)*Q(J,1) + S(2,I)*Q(J,2) + S(3,I)*Q(J,3)
       END DO
      END DO
C
C COMPUTE S  MATRIX
C          2
C
      COMG = COS(DTR*(360.0-ANG(2)))
      SOMG = SIN(DTR*(360.0-ANG(2)))
      S(1,1) = SPSI*COMG
      S(1,2) = CPSI*COMG
      S(1,3) = -SOMG
      S(2,1) = SPSI*SOMG
      S(2,2) = CPSI*SOMG
      S(2,3) = COMG
C
C          T    T
C COMPUTE S S PA
C          2 1
C
      DO I = 1,3
       DO J = 1,3
        Q(J,I) = S(I,1)*ROT(J,1) + S(I,2)*ROT(J,2) + S(I,3)*ROT(J,3)
       END DO
      END DO
C
C SWAP LATITUDE AND LONGITUDE FOR CONFORMANCE TO CRUISE MODE ROUTINES.
C
      TEMP = ANG(1)
      ANG(1) = ANG(2)
      ANG(2) = TEMP
C
      RETURN
      END