L3=128
		DOLOOP IAD=LI, L2, L3
		   IFSS-IAND(FMTBUF(D),255)
		   IF(IFSS.GT.127) IFSS:IFSS-256
		   JCOUNT-JCOUNT+l
		   NFSS-NFSS + IFSS
		ENDLOOP
C CONVERT INTO RADIANS
		IF(IGAIN.NE.O)THEN
C    IGAIN=1=> COARSE RESOLUTION => HIGH GAIN
		   ROLL=NFSS/SECFSH
		ELSE
C    IGAIN=O => FINE RESOLUTION => L0W GAIN
		   ROLL=NFSS/SECFSL
 		ENDIF
		IF(JCOUNT.NE.0) ROLL=ROLL/JCOUNT
C	CALL SUNCO ROUTINE TO GET ATTITUDE MATRIX UPDATED FOR ROLL
		CALL SUNCO(ATTC,SUN,SRA,SDE,ROLL,ICOUNT)
C CHECK	# OF ITERATIONS, JUST OUT OF INTEREST.
		IF(ICOUNT.GT.5)IRET=1
	  ENDIF
	ENDIF
C
	IF(DEBLUR)THEN
C GET PARAMETERS A511, 512, 513 (TRUE XYZ ERRORS)
           DOLOOP I=1, 3
		I2(1)=0
		I2(2)=FMTBUF(697+I)
		ERR(I)=(I4-D32768)/SECA*0.33DO
  	   ENDLOOP
C APPLY ROTATIONS ERRORS AROUND Y AND Z
	   CALL DROTX(ATTC,ERR(2),2)
	   CALL DROTX(ATTC,ERR(3),3)
C	APPLY ROTATION ABOUT X, IF ROLL ERROR AVAILABLE
C	(IF ROLL ERROR CORRECTION ALREADY PERFORMED THEN SKIP)
	  IF(ICRS1.NE.O.AND.ICFL.EQ.O.AND.SUNPRE)CALL DROTX(ATTC,ERR(1),1)
	ENDIF
	RETURN
	END
C
C
C
	SUBROUTINE SUNCO(ATT,SUN,SRA,SDE,ROLL,ICOUNT)
C
CP SUBROUTINE TO RECOMPUTE THE EXOSAT ATTITUDE MATRIX AS FUNCTION OF
CP STAR REFERENCE POSITION AND SUN EFFECTIVE POSITION
C
Cl ATT (3, 3)	R*8	OLD ATTITUDE MATRIX
Cl			ATT(l,l),ATT(2,l),ATT(3,I) =	STAR TRACKER X-AXIS
CI			ATT(I,2),ATT(2,2),ATT(3,2) =	STAR TRACKER Y-AXIS
ci			ATT(1,3),ATT(2,3),ATT(3,3) =	STAR TRACKER Z-AXIS
cl SUN(3)	R*8	S/C TO SUN UNIT VECTOR
Cl SRA		R*8	RIGHT ASCENSION Of REFERENCE STAR (RADIANS)
CI SDE		R*8	DECLINATION	OF REFERENCE STAR (RADIANS)
Cl ROLL		R*8	ACTUAL ROLL ERROR MEASURED BY FSS (RADIANS)
CI			(POSITIVE WHEN SUN IS BELOW X-Y PLANE)
CO ATT(3,3)	R*8	UPDATED ATTITUDE MATRIX (TWO-WAY PARAMETER!)
C
CO ICOUNT	I	ITERATION COUNT (FOR TESTING)
C
C
CC   PROJ-EXO, SUBJ-ATT, UTIL=SPEC, AUTH=A.SCHUETZ/ECD/OAD,AUG'86
C
CS SUBROUTINES CALLED
CS DRCTR ROTATES A SET OF REFERENCE AXES AROUND AN ARBITRARY AXIS
CS DROTX ROTATES A SET OF REFERENCE AXES AROUND ONE OF THEM
CS MVW	MOVE n 16-BIT WORDS FROM 2ND ARGUMENT TO 3RD ARGUMENT
C
	IMPLICIT REAL*8 (A-H,O-Z)
	DIMENSION ATT(3,3),SUN(3).FSSDAT(3)
C
CV LOCAL VARIABLES
CV FSSDAT(3) R*8	FINE SUN SENSOR DATA
CV			(1) = MISALIGNEMENT IN ROLL	(RADIANS)
CV			(2) = MISALIGNEMENT IN PITCH	(RADIANS)
CV			(3) = SCALE FACTOR
CV RLIM	   MINIMUM ROLL ERROR CORRECTION ON RADIANS	(=10 ARCSEC)
CV STAR    STAR UNIT VECTOR
CV FSSR    FINE SUN SENSOR REFERENCE AXES IN INERTIAL REFERENCE SYSTEM
CV SUNS    SUN UNIT VECTOR IN FSS REFERENCE SYSTEM
C
	DIMENSION STAR(3),SUNB(3),FSSR(3,3)
	DATA FSSDAT/.00285DO,.00049DO,I.ODO/	! = 9.8	1.7 ARC MINS
	DATA RLIM/4.848D-5/
C
C  IF PRESENT CONVERT STAR POSITION INTO A UNIT VECTOR (USE SUNB)
C  IF NOT ASSUME STAR IS ON X-AXIS
	IF(SRA.EQ.O.DO.AND.SDE.EQ.O.DO)THEN
C  COMMENT THIS OCCURS DURING CERTAIN CONTINGENCIES, BUT SUNCO
CI WILL STILL BEHAVE CORRECTLY.
		CALL MVW(12,ATT(1,1),SUNB)
	ELSE
C  COMMENT NORMAL CASE - VALID STAR COORDINATES - CONVERT
		SUND(l)=DCOS(SDE)*DCOS(SRA)
		SUNB(2)=DCOS(SDE)*DSIN(SRA)
		SUNB(3)=DSIN(SDE)
	ENDIF
C
C  EXPRESS STAR POSITION IN STAR TRACKER REFERENCE MATRIX
	STAR (1) =ATT(1,1)*SUNB(1)+ATT(2,1)*SUNB(2)+ATT(3,1)*SUNB(3)
	STAR (2) =ATT(1,2)*SUNB(1)+ATT(2,2)*SUNB(2)+ATT(3,2)*SUNB(3)
	STAR (3) =ATT(1,3)*SUNS(l)+ATT(2,3)*SUNB(2)+AIT(3,3)*SUNB(3)
C
	ICOUNT=0
C
    10 CONTINUE
	ICOUNT=ICOUNT+l
C
C INITIALISE FSS REFERENCE MATRIX TO STAR TRACKER REFERENCE MATRIX
	CALL MVW(36,ATT,FSSR)
C
C APPLY MISALlGNMEHTS IN ROLL AND PITCH
	CALL DROTX(FSSR,FSSDAT(1), 1)
	CALL DROTX(FSSR,FSSDAT(2),2)
C
C COMPUTE PREDICTED SUN POSITION IN FSS REFERENCE
	SUNB(1)=FSSR(1,1)*SUN(1) + FSSR(2,1)*SUN(2) + FSSR(3,1)*SUN(3)
	SUNB(2)=FSSR(1,2)*SUN(1) + FSSR(2,2)*SUN(2) + FSSR(3,2)*SUN(3)
	SUNB(3)=FSSR(1,3)*SUN(1) + FSSR(2,3)*SUN(2) + FSSR(3,3)*SUN(3)
C
C DERIVE PREDICTED ROLL ANGLE ERROR	(= MINUS ROLL ANGLE)
	PROLL=-DATAN(SUNB(3)/SUNB(2))
C
C RESIDUAL ROLL ERROR = ACTUAL - PREDICTED
	DROLL=ROLL*FSSDAT(3) - PROLL
C
C IF RESIDUAL ROLL ERROR IS SMALL ENOUGH RETURN
	IF(DABS(DROLL).LT.RLIM.OR.ICOUNT.GE.10)RETURN
C
C APPLY THAT CORRECTION TO THE INITIAL ATTITUDE MATRIX WITH THE