C+
C NAME:
C	ThomsonLOSDensity
C PURPOSE:
C CATEGORY:
C CALLING SEQUENCE:
	function ThomsonLOSDensity(ScEl)
C INPUTS:
C	ScEl			real	topocentric distance electron-observer (in 
C					solar radii)
C OUTPUTS:
C	ThomsonLOSDensity	real	density at electron location
C					(in electrons/cm^-3)
C CALLS:
C	Point_On_LOS, Thomson3DDensity
C SEE ALSO:
C	ThomsonSetupLOS
C PROCEDURE:
C >	ThomsonSetupLOS stores the input variables internally for use by
C	ThomsonLOSDensity.
C >	ThomsonLOSDensity uses its argument ScEl, and ScSun, SLng and SLat,
C	and uses Point_On_LOS to get the heliocentric coordinates of the
C	electron. Then Thomson3DDensity is called to get the density.
C >	Thomson3DDensity is a user-defined function, which returns the
C	density for a given heliocentric location, specified as longitude,
C	latitude (deg) and distance (solar radii).
C		D = Thomson3DDensity(ScLng+ElLng,ScLat+ElLat,ScSun*ElSun)
C MODIFICATION HISTORY:
C	JAN-1998, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	    real	ScEl

	save    ScSun, ScLng, ScLat, SLng, SLat

	ElLng = SLng			! Longitude l.o.s.
	ElLat = SLat			! Latitude  l.o.s.
	ElSun = ScEl/ScSun		! Sc-El dist along l.o.s. (units: Sc-Sun dist)

	call POINT_ON_LOS(ElLng,ElLat,ElSun,Elo1,Elo2,iEorW)

	ThomsonLOSDensity = Thomson3DDensity(ScLng+ElLng,ScLat+ElLat,ScSun*ElSun)

	return
C+
C NAME:
C	ThomsonSetupLOS
C PURPOSE:
C CATEGORY:
C CALLING SEQUENCE:
	entry ThomsonSetupLOS(ScLngIn,ScLatIn,ScSunIn,SLngIn,SLatIn)
C INPUTS:
C	ScLngIn		real	heliocentric (ecliptic) longitude observer (deg)
C	ScLatIn		real	heliocentric (ecliptic) latitude observer (deg)
C	ScSunIn		real	heliocentric distance observer (in solar radii)
C	SLngIn		real	topocentric (ecliptic) longitude line of sight
C				relative to Sun-observer direction
C	SLatIn		real	topocentric (ecliptic) longitude line of sight
C				relative to Sun-observer direction
C OUTPUTS:
C	ThomsonSetupLOS	real	always 1
C SEE ALSO:
C	ThomsonLOSDensity
C PROCEDURE:
C >	Entry point in ThomsonLOSDensity
C >	Only serves to store the input variables internally for use by
C	ThomsonLOSDensity.
C MODIFICATION HISTORY:
C	JAN-1998, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C-
	ThomsonSetupLOS = 1.

	ScSun = ScSunIn			! Sc-Sun dist (solar radii)
	ScLng = ScLngIn			! Heliocentric longitude Sc (deg)
	ScLat = ScLatIn			! Heliocentric latitude  Sc (deg)

	SLng  = SLngIn			! Topocentric longitude l.o.s. (deg)
	SLat  = SLatIn			! Topocentric latitude  l.o.s. (deg)

	return
	end