NAME:
	ScEarth
 PURPOSE:
	Returns the heliographic or ecliptic longitude of the Earth for a given time
 CALLING SEQUENCE:
	FUNCTION ScEarth, T,	$
	    ecliptic	= ecliptic  , $
	    degrees	= degrees   , $
	    eastlimb	= eastlimb  , $
	    westlimb	= westlimb
 INPUTS:
	T	scalar, array; type: standard time structure
		    times
 OPTIONAL INPUTS:
	/degrees    if set, angles are in degrees (default: radians)
	/ecliptic   if set, the ecliptic longitude is returned
	/eastlimb   if set, the longitude of the east limb is returned
	/westlimb   if set, the longitude of the west limb is returned
 OUTPUTS:
	ScEarth     heliographic longitude (degrees, 0<=EARTH<360)
 INCLUDE:
	@compile_opt.pro	; On error, return to caller
 CALLS: ***
	CvSky, InitVar, SubArray, ToRadians, jpl_eph
 CALLED BY:
	CarringtonT, CarringtonT0, CarringtonVar
 PROCEDURE:
 MODIFICATION HISTORY:
	JAN-1991, Paul Hick (UCSD/CASS)
	JUL-1993, Paul Hick (UCSD/CASS), added option to return ecliptic longitude
	OCT-1994, Paul Hick (UCSD/CASS), converted from F77 (functions SC_EARTH,
	    SC_EARTH_ELIMB, SC_EARTH_WLIMB)
	FEB-2007, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
	    Replaced NewcombSun call by call to jpl_eph.
	    The difference should be a few thousands of a degree.

 NAME:
	smei_time
 PURPOSE:
	Extract time range and duration from name of SMEI-related file
 CATEGORY:
	camera/idl/buf
 CALLING SEQUENCE:
	FUNCTION smei_time, name    , $
	    duration	= duration  , $
	    xband	= xband     , $
	    range	= range     , $
	    noduration	= noduration
 INPUTS:
	name		scalar or array[n]; type: string
			    file name
 OUTPUTS:
	ut		array[n] or array[n,2]: type: time structure
			    start and stop time
 OPTIONAL OUTPUT PARAMETERS:
	duration=duration
			array[1]; type: time difference structure
			    duration (= time between start and stop time)
	/range
	/noduration	if set, do not check for duration
 INCLUDE:
	@compile_opt.pro	; On error, return to caller
 CALLS: ***
	GetFileSpec, InitVar, SetFileSpec, TimeOp, TimeSet, flt_string, smei_coriolis
 PROCEDURE:
	Files that can be processed include:

	L1A files  : L1A_YYYY_DDD_hhmmss_hhmmss (4 underscores)
	SMEI frames: c1frm_YYYY_DOY_hhmmss (3 underscores)
	CVID files : COR_SVAL3_2004_163_12_06_V (6 underscores)
			 FBKS_2004_163_12_06_V (5 underscores)

	The number of underscores are used to dissect the name.
 MODIFICATION HISTORY:
	JUL-2003, Paul Hick (UCSD/CASS)
	JUN-2004, Paul Hick (UCSD/CASS)
	    CVID files without the COR_ prefix started to appear.
	    Modified to handle the new situation: if 6 underscores
	    are present in a VCID file (/xband set) then the first
	    one is skipped (it used to skip the first underscore
	    unconditionally)
	OCT-2004, Paul Hick (UCSD/CASS)
	    Fixed bug in calculation of duration of L1A file.
	APR-2006, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
	    Added option to get time from string 'orbit_12345' in
	    file name
	APR-2007, Paul Hick (UCSD/CASS)
	    File names of type c2sky_YYYY_DOY_hhmmss_tmp.fts
	    (i.e. 4 underscores followed by something else then
	    a duration) are now recognized. They used to generate
	    errors since they were interpreted as L1A file names.

 NAME:
	smei_TimePosn
 PURPOSE:
	Dissect name of SMEI-related file
 CATEGORY:
	camera/idl/toolbox
 CALLING SEQUENCE:
	FUNCTION smei_TimePosn, files, $
	    camera  = camera	, $
	    id	    = id	, $
	    time    = time	, $
	    format  = format	, $
	    extract = extract
 INPUTS:
	files		array; type: string
			    list of file names. Only the name part is
			    analyzed, i.e. directory and extension are
			    ignored
 OUTPUTS:
	pos		array: type: integer
			    start position of time in 'names';
			    -1 if no time is found
 OPTIONAL OUTPUT PARAMETERS:
	camera=camera	array; type; integer
			    camera number
	id = id 	array; type: string
			    string id of SMEI file type, e.g. 'm0','m1','m2','sky',etc.
	time=time	array; type: time structure
			    time extracted from file name
	format=format	array; type: string
			    format used to extract time
 INCLUDE:
	@compile_opt.pro	; On error, return to caller
 CALLS: ***
	GetFileSpec, InitVar, SyncArgs, strposn, timeposn
 PROCEDURE:
 MODIFICATION HISTORY:
	JUL-2005, Paul Hick (UCSD/CASS; pphick@ucsd.edu)