computes doppler profile given 

 ny0 - line frequency at rest
 ny - frequency grid
 te - temperature of formation of line
 u(x,y) - velocity
 chi: non-thermal line broadening in km/s
 awgt: atomic weight of atom

 output: phiny(ny,x,y)
 
 Oivind Wikstol     12.02.04  ver 1.0

 NAME:
	PHOTONS_TO_ENERGY

 PURPOSE:
	Convert intensity from photons [ph m-2 s-1 sr-1] to energy in SI units
       [W m-2 sr-1]
	

 CATEGORY:
	Solar-B utilities software

 CALLING SEQUENCE:
	photons_to_energy, inval, wavel, outval


 INPUTS:
	inval:	Input intensity ([ph m-2 s-1 sr-1])
       wavel:  photon wavelength IN ANGSTROMS!!

 KEYWORD PARAMETERS:

 OUTPUTS:
	outval:  Intensity in SI units[W m-2 sr-1]

 CALLS:
 COMMON BLOCKS:

 PROCEDURE:

 RESTRICTIONS:
	Input in SI, i.e. [ph m-2 s-1 sr-1]
	Photon wavelength in ANGSTROM only

 MODIFICATION HISTORY:
	07-Sep-2005: Written by Oivind Wikstol

 Project     : SMM-XRP

 Name        : PLOT_HELIO

 Purpose     : Plot solar heliographic grid and limb

 Category    : Plotting

 Explanation : Uses heliographic formulae from:
               "Textbook on Spherical Astronomy",
               by W.M. Smart (see page 174).

 Syntax      : plot_helio,date,grid=grid,glabel=glabel

 Inputs      : DATE = date/time

 Opt. Outputs: LAT,LON = latitude and longitude arrays

 Keywords    : GRID_SPACING = spacing (deg) of lat-long  [def = 10]
               GLABEL = label lat-long grid with coordinate values (def = no labels)
               OVER = control erasing of previously drawn plot. Setting this
                        to 1 will cause grid to be overlaid on a drawn plot
               GCOLOR  = color index for grid
               GFONT   = gfont index for grid label
               ROLL = solar roll (deg) clockwise from solar north
               CENTER = roll center [def = 0,0]
               GSTYLE = grid linestyle [def=0]
               XRANGE,YRANGE = data ranges in arcsecs
               LIMB_PLOT =  plot limb
               LMCOLOR = color index for limb
               LMTHICK = thickness of limb
          POSITION = Allows direct specification of the plot window.

 CALLS: ***
	ANYTIM2UTC [1], ANYTIM2UTC [2], DPRINT, EXIST, GET_UTC, HEL2ARCMIN [1]
	HEL2ARCMIN [2], IS_WOPEN, NINT [1], NINT [2], PB0R, WDEF [1], WDEF [2], is_number [1]
	is_number [2], roll_xy
 CALLED BY:
	PLOT_CDS_POINT [1], PLOT_CDS_POINT [2], PLOT_MAP
	PLOT_MAP2 WARNINGTEMPORARY FIX ONLY FOR 16 bit ZBuffer support
	SOLB_PLOT_POINTING [1], SOLB_PLOT_POINTING [2]
 History     : Written, 22 December 1991, D. Zarro, ARC/GSFC
               Modified,30 November 1999, Zarro (SM&A/GSFC) - added RANGE
                keywords
               Modified,17 April 2000, Zarro (SM&A/GSFC) - added /LIMB
               and made SOHO/Yohkoh cross-compatible
               Modified, 1-Sept-2001, Zarro (EITI/GSFC) - ensure PSYM=0
               when plotting limb
               Modified, 16-Sept-2001, Zarro (EITI/GSFC) - added
               check for ROLL_CENTER within image
               Modified, 10-Oct-2001, Zarro (EITI/GSFC) - fixed bug in
               limb calculation when roll is applied
               Modified, 10-Jan-2002, Zarro (EITI/GSFC) - fixed bug in
               use of /SOHO
               Modified, 4-Nov-2002, Zarro (EER/GSFC) - added GCOLOR
               Modified, 23-Feb-2004, Kim Tolbert - added lmthick
               Modified, 24-Feb-2004, Zarro (L-3Com/GSFC) - changed
               lcolor to lmcolor for consistency with lmthick
               Modified, 26-Oct-2004, Yurow (L-3Com/GSFC) - added
               POSITION keyword that is passed to the plot command.

 Contact     : dzarro@solar.stanford.edu