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Last modified: Mon Nov 27 16:11:52 2006.

List of Routines

Routine Descriptions

RT_AAREADME

 [Next Routine] [List of Routines] 
 NAME:
   rt_AAREADME
 PURPOSE
   Print the file 'rt_AAREADME.pro'
 CATEGORY:
  Radiative Transfer (rt)
 CALLING SEQUENCE:
  rt_AAREADME
 
 ---------------------------------------------------------------------------
 FILES AND ENVIRONMENT VARIABLES
 ---------------------------------------------------------------------------

 ---------------------------------------------------------------------------
 FUNCTIONS
 ---------------------------------------------------------------------------
 
   atm1 = rt_atmread1('titan.atm') - read atm file

 ---------------------------------------------------------------------------
 VARIABLES
 ---------------------------------------------------------------------------
 
 atm1: structure with
   nz, ns, z, p, t, n, ncol

 n   number density [nz,ns] (cm^-3)
 ncol   number column density [nz,ns] (cm^-2)
 ns  number of species
 nz  number of atmospheric levels
 p   pressures [nz] (microbar)
 t   temperatures [nz] (K)
 z   altitudes [nz]  (cm)

 ---------------------------------------------------------------------------

(See rt_AAREADME.pro)

RT_ATMREAD1

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_atmread1
 PURPOSE: (one line)
  read a model atmosphere
 DESCRIPTION:
  read a model atmosphere, return atmospheric structure
 CATEGORY:
  RT
 CALLING SEQUENCE:
  atm = rt_atmread1(fname)
 INPUTS:
  fname = file name of atmospheric structure
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
    returns an atmosphere structure, with the following fields
    nz  number of atmospheric levels
    ns  number of species
    z   altitudes [nz]  (cm)
    p   pressures [nz] (microbar)
    t   temperatures [nz] (K)
    n   number density [nz,ns] (cm^-3)
    ncol   number column density [nz,ns] (cm^-2)
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 EXAMPLE:
  atm1 = rt_atmread1('titan.atm') 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on atmread1.f, written by Roger Yelle, 1990

(See rt_atmread1.pro)

RT_ATMREAD2

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_atmread2
 PURPOSE: (one line)
  read a model atmosphere
 DESCRIPTION:
  read a model atmosphere, return atmospheric structure
 CATEGORY:
  RT
 CALLING SEQUENCE:
  atm = rt_atmread2(fname, pmax)
 INPUTS:
  fname = file name of atmospheric structure
  pmax = maximum pressure (ubar) 
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
    returns an atmosphere structure, with the following fields
    nz  number of atmospheric levels
    ns  number of species
    z   altitudes [nz]  (cm)
    p   pressures [nz] (cm)
    t   temperatures [nz] (K)
    n   number density [nz,ns] (cm^-3)
    ncol   number column density [nz,ns] (cm^-2)
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  Modifies atm
 PROCEDURE:
 
 EXAMPLE:

  atm = rt_atmread2('titan.atm',1.d+2)
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on atmread2.f, written by Roger Yelle, 1990

(See rt_atmread2.pro)

RT_BANDREAD

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_bandread
 PURPOSE: (one line)
  read bandparams.dat
 DESCRIPTION:
  read bandparams.dat, return band structure
 CATEGORY:
  RT
 CALLING SEQUENCE:
  band = rt_bandread
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  band structure
   wave
   arad
   pcol
   dgn
   rmass
   rdmol
   qrot - exponent for rotational partition function
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on mesopause.f, written by Roger Yelle, 1990

(See rt_bandread.pro)

RT_CASCADE

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_cascade
 PURPOSE: (one line)
  calculate methane cascade heating
 DESCRIPTION:

 CATEGORY:
  RT
 CALLING SEQUENCE:
  hcsc = rt_cascade(efc, rmass, rh, $
                 wav0, wdel, xu, wu, nu, atm, ep1, ep2, $
                 ssolar, th)
 INPUTS:

 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  cascade heating rate in erg/cm^3/s
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  Modified from cascade.f, Roger Yelle

(See rt_cascade.pro)

RT_CGRID

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_cgrid
 PURPOSE: (one line)
  interpolate a model atmosphere onto evenly spaced pressures 
 DESCRIPTION:
  interpolate a model atmosphere onto evenly spaced pressures 
 CATEGORY:
  RT
 CALLING SEQUENCE:
  rt_cgrid, dat, nz, atm
 INPUTS:
  dat : body-specific constants
  nz : number of new atmospheric pressure levels 
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  none
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  Modifies atm
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on cgrid.f, written by Roger Yelle, 1990

(See rt_cgrid.pro)

RT_DEPSLN

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_depsln
 PURPOSE: (one line)
  return normalized derivative of epsln
 DESCRIPTION:

 CATEGORY:
  RT
 CALLING SEQUENCE:
  ep = rt_depsln(t,ntot,a10,p10,d,m)
 INPUTS:
  t - temperature (K). May be an array.
  ntot - total number density (cm^-3). May be an array.
  a10 - einstein A coefficient. s^-1
  p10 - V-T transition probability. Unitless.
  d - collision diameter. cm
  m - reduced mass. g
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 16, Leslie Young SwRI
  Modified from depsln.f, Roger Yelle

(See rt_depsln.pro)

RT_EPSLN

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 NAME:
  rt_epsln
 PURPOSE: (one line)
  return ratio of collision timescale to radiaitve timescale
 DESCRIPTION:

 CATEGORY:
  RT
 CALLING SEQUENCE:
  ep = rt_epsln(t,ntot,a10,p10,d,m)
 INPUTS:
  t - temperature (K). May be an array.
  ntot - total number density (cm^-3). May be an array.
  a10 - einstein A coefficient. s^-1
  p10 - V-T transition probability. Unitless.
  d - collision diameter. cm
  m - reduced mass. g
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  c10/a10
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  Modified from epsln.f, Roger Yelle

(See rt_epsln.pro)

RT_FINTRP

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_fintrp
 PURPOSE: (one line)
  interpolate into an ordered list
 DESCRIPTION:
 CATEGORY:
  RT
 CALLING SEQUENCE:
  y = rt_fintrp(xtab, ytab, xx)
 INPUTS:
  xtab - array of x's
  ytab - matching array of y's
  x - value at which we want the interpolated y   
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
  first calls rt_locate
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on finterp, in locate.f

(See rt_fintrp.pro)

RT_HITRAN

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_hitran
 PURPOSE: (one line)
  read hitran files
 DESCRIPTION:
  read hitran files
 CATEGORY:
  RT
 CALLING SEQUENCE:
  lines = rt_hitran(fn, selmin, selmax)
 INPUTS:
  filename - hitran file
  selmin - minimum wavenumber for selection
  selmax - maximum wavenumber for selection
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 KEYWORD OUTPUT PARAMETERS:
 OUTPUTS:
  structure with:
    wav, str, wid, eng, nlines, stot, wav0, wmin, wmax 
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on hitran.f, written by Leslie Young, 1998

(See rt_hitran.pro)

RT_LOCATE

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_locate
 PURPOSE: (one line)
  Search an ordered list by bisection
 DESCRIPTION:
  Given an array xx[0..n-1], and given a value x, returns a value j
  such that x is between xx[j] and xx[j+1]. 
  xx must be monotonic, either increasing or decreasing. 
  j=-1 or j=n-1 is returned to indicate that x is out of range.
 CATEGORY:
  RT
 CALLING SEQUENCE:
  j = rt_locate(xx, x)
 INPUTS:
  xx - array, monotonic, either increasing or decreasing
  x - the value to be found in xx
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  j such that  x is between xx[j] and xx[j+1]. 
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
  Modifies from locate, numerical recipes
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on locate, Numerical Recipes, Press et al.

(See rt_locate.pro)

RT_MESOPAUSE

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_mesopause
 PURPOSE: (one line)
  Reproduce the behavior of mesopause.f
 DESCRIPTION:
  Reproduce the behavior of mesopause.f
 CATEGORY:
  RT
 CALLING SEQUENCE:
  mesopause
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  collision rate/deexcitation rate
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  based on mesopause.f, written by Roger Yelle, 1990

(See rt_mesopause.pro)

RT_RANDOM

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_random
 PURPOSE: (one line)
  calculate molecular opacity in a specified frequency range
 DESCRIPTION:
 *********************************************************************
 *                                                                   *
 *     RANDOM calculate the molecular opacity in a specified         *
 *     frequency range.  Required input consists of an array of      *
 *     line positions, widths, strengths, and quantum numbers.       *
 *     The S-1 random model with a Curtis-Godson approximation       *
 *     is used.  The relevant equations are described by Wallace,    *
 *     Prather, and Belton, Ap. J., 1974, Vol 193, pp 481-493.       *
 *                                                                   *
 *********************************************************************

 CATEGORY:
  RT
 CALLING SEQUENCE:
  a = rt_random (uu,prs,tmp,col,str,wid,eng,efc,rmass,wmid,delnu)
 INPUTS:
       INPUT

            uu   - cosine of solar zenith  angle
            prs  - pressure grid (atm)
                   not ubar?  [LAY]
            tmp  - temperature grid (Kelvins)
            col  - column density grid (cm-2)
            str  - list of line strengths (cm-1)
            wid  - Lorentz widths of lines at a ref. temperature
                   (cm-1)
                   and std pressure? [LAY]
            eng  - energy of lower state (cm-1)
            rmass - molecular mass in g
            efc - rotational partition function exponent
            wmid  - frequency in center of interval (cm-1)
            delnu - range of frequency covered by these lines
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
            a - average absorption in this frequency interval
 
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
 
 MODIFICATION HISTORY:
  Written 2004 May 12, Leslie Young SwRI
  Modified from random.f, Roger Yelle

(See rt_random.pro)

RT_REDUCEDMASS

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_reducedmass
 PURPOSE: (one line)
  Return the reduced mass of two molecules
 DESCRIPTION:
  Return the reduced mass of two molecules
 CATEGORY:
  RT
 CALLING SEQUENCE:
  eps = rt_vtefficiency(t, n, a10, p10, moldiam, molwgt)
 INPUTS:
  molwgt1 - molecular weight of first molecule
  molwgt2 - molecular weight of 2nd molecule
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  collision rate/deexcitation rate
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 
  Simple formular for reduced mass.  Could be extended with
  Yelle 1991. "Non-LTE models of Titan's upper atmosphere,"
  ApJ 383, 380-400, eqn 18.
 
 MODIFICATION HISTORY:
  Written 2004 Mar 17, Leslie Young SwRI
  based on line 177 of mesopause.f, written by Roger Yelle, 1990

(See rt_reducedmass.pro)

RT_SOLIRFLX

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_solirflx
 PURPOSE: (one line)
  return solar IR flux
 DESCRIPTION:

 CATEGORY:
  RT
 CALLING SEQUENCE:
  flx = rt_solirflx(ww)
 INPUTS:
  ww - flux in wavenumbers
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 KEYWORD OUTPUT PARAMETERS:
 OUTPUTS:
  solar flux in erg/cm^2/s/invcm at 1 AU
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
  calls expm1, which returns exp(x)-1, even for small x.
 MODIFICATION HISTORY:
  Written 2004 May 8, Leslie Young SwRI
  Modified from routine in cascase.f, Roger Yelle

(See rt_solirflx.pro)

RT_SOLREAD

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_solread
 PURPOSE: (one line)
  read solar spectrum and cross sections
 DESCRIPTION:
  read solar spectrum and cross sections
 CATEGORY:
  RT
 CALLING SEQUENCE:
  sol = rt_solread( cycle = cycle, refdir = refdir)
 INPUTS:
  None
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  cycle = 0 for solar max, 1 for solar min
  refdir: directory of soluvmax.dat or soluvmin.dat
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  structure with:
  wave[nsol] - wavelength in A
  dwave[nsol] - width of wavelength interval in A
  flux[nsol] - flux in photon/cm^2/s/A
  crs[nsol,4] - cross section of N2, CH4, C2H2, C2H6 (cm^2)  
  nsol - number of solar lines
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 MODIFICATION HISTORY:
  Written 2004 Mar 20, Leslie Young SwRI
  based on solread, written by Roger Yelle, 1990
  2004 Mar 21 LAY added dwave, changed flux to 
   ph/cm^2/s/A, not ph/cm^2/s/interval
  2004 May 8 LAY change syntax to return a structure

(See rt_solread.pro)

RT_SREAD

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_sread
 PURPOSE: (one line)
  read line listings for fundementals
 DESCRIPTION:
  read line listings for fundementals
 CATEGORY:
  RT
 CALLING SEQUENCE:
  sread=rt_sread(indx)
 INPUTS:
  indx - indices of line files
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  structure with:
    nb - number of listings
    nlines[nb] - number of lines for each band
    stot[nb]
    wmean[nb]
    wstart[nb]
    wend[nb] 
    nl - index into wav, str, wid, eng
    n - number of lines
    wav[n] wavenumber of line
    str[n] str of line in cm^-1/(molecule cm^-2)
    wid[n] pressure width in invcm at STP
    eng[n] lower state energy in invcm
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 MODIFICATION HISTORY:
  Written 2004 Mar 20, Leslie Young SwRI
  based on sread, written by Roger Yelle, 1990

(See rt_sread.pro)

RT_UVHEAT

 [Previous Routine] [Next Routine] [List of Routines] 
 NAME:
  rt_uvheat
 PURPOSE: (one line)
  calculate UV heating rate
 DESCRIPTION:
  calculate global average of UV heating rate given data from solread
 CATEGORY:
  RT
 CALLING SEQUENCE:
  ht = rt_uvheat(rh,col,den,wave,flux,crs)
 INPUTS:
  rh - heliocentric distance (AU)
  atm structure with
   ncol[nz,5] - vertical column densities of N2, CH4, C2H2, C2H6, HCN (cm^-2)
   n[nz,5] - number densities of N2, CH4, C2H2, C2H6, HCN (cm^-3)
  sol structure with
   wave[nsol] - wavelength in A
   dwave[nsol] - wavelength interval in A
   flux[nsol] - flux in photon/cm^2/s/A
   crs[nsol,4] - cross section of N2, CH4, C2H2, C2H6 (cm^2)  
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  ht[ntau] - heating rate in erg/cm^3/s
  ht4[ntau, 4] - heating rate in erg/cm^2/s for N2, CH4, C2H2, C2H6
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 MODIFICATION HISTORY:
  Written 2004 Mar 20, Leslie Young SwRI
  based on uvheat.f, written by Roger Yelle, 1990
  with more array arithmetic
  2004 May 9, LAY SwRI - take uv structure as input

(See rt_uvheat.pro)

RT_VTEFFICIENCY

 [Previous Routine] [List of Routines] 
 NAME:
  rt_vtefficiency
 PURPOSE: (one line)
  Return the ratio of collision rate to spontaneous deacy rate
 DESCRIPTION:
  Return the ratio of collision rate to deacy rate
 
  See Yelle 1991. "Non-LTE models of Titan's upper atmosphere,"
  ApJ 383, 380-400, eqn 10.
 
 CATEGORY:
  RT
 CALLING SEQUENCE:
  eps = rt_vtefficiency(t, n, a10, p10, moldiam, molwgt)
 INPUTS:
  t - temperature (K)
  n - number density of the background atmosphere (cm^-3)
  a10 - Einstein A10 coefficient (s^-1)
  p10 - collision probability (unitless)
  moldiam - reduced diameter of the molecules (cm)
  molwgt - reduced molecular weight
 OPTIONAL INPUT PARAMETERS:
  none
 KEYWORD INPUT PARAMETERS:
  none
 KEYWORD OUTPUT PARAMETERS:
  none
 OUTPUTS:
  collision rate/deexcitation rate
 COMMON BLOCKS:
  None
 SIDE EFFECTS:
 RESTRICTIONS:
  None
 PROCEDURE:
 MODIFICATION HISTORY:
  Written 2004 Mar 17, Leslie Young SwRI
  based on epslnf, written by Roger Yelle, 1990

(See rt_vtefficiency.pro)