C+
C NAME:
C	get_scparams.f
C PURPOSE:
C	Read STEREO A velocity data into arrays
C CATEGORY:
C	I/O
C CALLING SEQUENCE:
C	call get_scparams(nCar,JDCar,NCoff,NLmax,IPNL,nYR,TDOYS8,Radius,VEL,
C     &		XDS,XLS,XLL,XDL,XCE,XE,XC,YL,RA,DEC)
C
C INPUTS:
C   get_scparams:
C	isc		integer		spacecraft/planet identifier
C					1  = Mercury
C					2  = Venus
C					3  = Earth
C					4  = Mars
C					5  = Jupiter
C					6  = Saturn
C					7  = Uranus
C					8  = Neptune
C					9  = Pluto
C					10 = Ulysses
C					11 = Helios-1
C					12 = Helios-2
C					13 = STEREO-A
C					14 = STEREO-B
C					15 = Messenger
C					
C	nCar		integer		dimension of JDCar
C	JDCar(nCar)	integer		start times (Julian days) of Carrington rotations
C	NCoff		integer		JDCar(I) is the start of rotation NCoff+I
C	NLmax		integer		max. # points read into arrays
C	IPNL		integer		# of this array element
C	nYr		integer		The year of this observation
C	Doy8(NLmax)	real*8		The time of this observation: day of year (incl. fraction for time of day)
C
C OUTPUTS:
C	XDS (NLmax)	real		Sun-spacecraft distance
C	XLS (NLmax)	real		geocentric ecliptic longitude of spacecraft
C	XLL (NLmax)	real		geocentric ecliptic lng(spacecraft)-lng(Sun) (deg)
C	XDL (NLmax)	real		geocentric ecliptic lat(spacecraft) (deg)
C	XCE (NLmax)	real		modified Carrington variable position of spacecraft
C	XE  (NLmax)	real		elongation (deg) (>0: East of Sun; <0: West of Sun) (0.0 for in-situ measurments)
C	XC  (NLmax)	real		modified Carrington variable spacecraft after traceback to
C					  heliocentric distance Radius at speed VV (not used in mkpostd_ins)
C	YL(NLmax)	real		heliographic latitude of spacecraft (not used in mkpostd_ins)
C	RA		real		Spacecraft right ascention
C	DEC		real		Spacecraft declination
C MODIFICATION HISTORY:
C	March-2014, Bernard Jackson (UCSD)
C-
	subroutine get_scparams(isc,nCar,JDCar,NCoff,NLmax,IPNL,nYR,Doy8,XCcntr,Radius,VEL,
     &		                XDS,XLS,XLL,XDL,XCE,XE,XC,YL,SCRA,SCDEC)
C
	real*8		JDCar(nCar),
     &			JEpoch,
     &			Doy8
C
	real*8		dLngSun, dLatSun, dDisSun
C
	real		XDS (NLmax),			! Sun-Spacecraft distance (AU)
     &			XLS (NLmax),			! Topocentric ecliptic longitude of spacecraft
     &			XLL (NLmax),			! Geocentric ecliptic lng(spacecraft)-lng(Sun) (deg)
     &			XDL (NLmax),			! Geocentric ecliptic lat(spacecraft) (deg)
     &			XCE (NLmax),			! Modified Carrington variable position of spacecraft
     &			XE  (NLmax),			! Elongation (deg) (>0: East of Sun; <0: West of Sun) (0.0 for in-situ measurments)
     &			XC  (NLmax),			! modified Carrington variable spacecraft after traceback to
C					  		  heliocentric distance Radius at speed VV (not used in mkpostd_ins)
     &			YL  (NLmax)			! Heliographic latitude of spacecraft (not used in mkpostd_ins)
C
	real		RVect(3)
C
	external	EARTH8
	include		'sun.h'
	include		'dirspec.h'
C
C		XCcntr    = 4.0					! Not correct
		call ExtractPositionn8(isc,nYr,Doy8,RVect)	! Spacecraft heliographic coordinates
	        XDS(IPNL) = RVect(3)				! Sun - STEREO A distance
		SCelon    = RVect(1)
		SCelat    = RVect(2)
	        call ECLIPTIC_HELIOGRAPHIC8(1,nYr,Doy8,SCelon,SCelat) ! Convert from spacecraft heliographic to ecliptic coordinates
		XLS(IPNL) = SCelon + 180.0			! Geocentric ecliptic longitude of the spacecraft
	        call SunNewcomb8(0,nYr,Doy8,dLngSun,dLatSun,dDisSun)
		alongsc   = SCelon - sngl(dLngSun) +180.0	! Topocentric longitude S/C diff. with Earth-Sun line
	        XLL(IPNL) = SCelon - (sngl(dLngSun) - 180.0)	! Topocentric ecliptic longitude S/C diff. with Earth-Sun line (0.0 for Earth)
	        XDL(IPNL) = -SCelat				! Geocentric ecliptic latitude of the spacecraft (0.0 for Earth)
C		Ehlon = sngl(dLngSun) - 180.0
C		Ehlat = 0.0
C	        call ECLIPTIC_HELIOGRAPHIC8(0,nYr,Doy8,Ehlon,Ehlat) 	! Convert from ecliptic to Sun location heliographic coordinates
		SCME = RVect(1)
		if(SCME .gt. 360.0) SCME = SCME - 360.0
		if(SCME .lt. 0.0)   SCME = SCME + 360.0
	     	XCsc = XMAP_OBS_POS(XCcntr,SCME)		! Modified Carrington variable of spacecraft
		XCE(IPNL) = XCsc				! Modified Carrington variable position of spacecraft
C
		if(alongsc .gt. 180.0) alongsc = alongsc - 360.0
		if(alongsc .gt. 180.0) alongsc = 360.0 - alongsc
		if(alongsc .lt.-360.0) alongsc = alongsc + 360.0
		if(alongsc .lt.-180.0) alongsc = alongsc + 360.0
		signalongsc = -1.0
		if(alongsc .lt. 0.0) signalongsc = 1.0
		ecdistsc = RVect(3)*cosd(SCelat)
		eceascdist = sqrt((sngl(dDisSun)*sngl(dDisSun)) + (ecdistsc*ecdistsc) -2.0*sngl(dDisSun)*ecdistsc*cosd(alongsc))
		cosecalongsc = ((eceascdist*eceascdist) + (sngl(dDisSun)*sngl(dDisSun)) - (ecdistsc*ecdistsc))/(2.0*eceascdist*sngl(dDisSun))
		ecscdist = RVect(3)*sind(-SCelat)
		sceaang = atan2d(ecscdist,eceascdist)
		coselong  = cosecalongsc*cosd(sceaang)	

		XE (IPNL) = acosd(coselong)*signalongsc		! Elongation (deg) of spacecraft
								! (>0: East of Sun; <0: West of Sun) (elongation of spacecraft)
 	        XCobs = XCsc+(Radius-RVect(3))/VEL*SUN__SPIRAL	! spacecraft traced to Radius
	        XC (IPNL) = XCobs				! modified Carrington variable spacecraft after traceback to
C					  		  	  heliocentric distance Radius at speed VV (not used in mkpostd_ins)
		YL (IPNL) = RVect(2)				! Heliographic latitude of spacecraft (not used in mkpostd_ins)

		SCRA   =  SCelon + 180.0
		SCDEC  =  -SCelat
		call ecliptic_equator8(0,nYr,Doy8,SCRA,SCDEC) 	! Right ascention and declination of the spacecraft
C		if(IPNL.eq.4887) stop
		if(IPNL.eq.3685.or.IPNL.eq.4886) then
		  print *, ' '
		  write (*,'(10F10.6)') signalongsc, RVect(3), ecdistsc, eceascdist, ecscdist, sceaang, acosd(coselong)*signalongsc
		  write (*,'(2I5,11F10.4)') IPNL, nYr, Doy8, XCcntr, SCelon, sngl(dLngSun), alongsc, XLL(IPNL), SCME, Ehlon, XCsc, SCRA, SCDEC 
		end if
	return
	end