m_physics.cc

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/* Copyright (C) 2002-2008
   Patrick Eriksson <Patrick.Eriksson@rss.chalmers.se>
   Stefan Buehler   <sbuehler@ltu.se>
                            
   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA. */
 
 
 
/*===========================================================================
  ===  File description
  ===========================================================================*/
 
/*===========================================================================
  === External declarations
  ===========================================================================*/
 
#include "arts.h"
#include "auto_md.h"
#include "check_input.h"
#include "logic.h"
#include "math_funcs.h"
#include "messages.h"
#include "physics_funcs.h"
 
extern const Numeric COSMIC_BG_TEMP;
extern const Numeric TEMP_0_C;
 
 
/*===========================================================================
  === The functions (in alphabetical order)
  ===========================================================================*/
 
 
/* Workspace method: Doxygen documentation will be auto-generated */
void complex_nWaterLiebe93(Matrix&         complex_n,
                           const Vector&   f_grid,
                           const Numeric&  t,
                           const Verbosity& verbosity)
{
  CREATE_OUT2
  CREATE_OUT3
  
  chk_if_in_range( "t", t, TEMP_0_C, TEMP_0_C+100 );
  chk_if_in_range( "min of f_grid", min(f_grid), 10e9, 1000e9 );
  chk_if_in_range( "max of f_grid", max(f_grid), 10e9, 1000e9 );
 
  out2 << "  Sets *complex_n* to model properties of liquid water,\n"
       << "  according to Liebe 1993\n";
  out3 << "     temperature      : " << t << " K.\n";
 
  const Index   nf = f_grid.nelem();
 
  complex_n.resize( nf, 2 );
 
  // Values from epswater93.m (by C. Mätzler), part of Atmlab.
  // The constant e2 is here set to 3.52, which according to Mätzler 
  // corresponds to Liebe 1993.
  const Numeric   theta = 1 - 300 / t;
  const Numeric   e0    = 77.66 - 103.3 * theta;
  const Numeric   e1    = 0.0671 * e0;
  const Numeric   f1    = 20.2 + 146.4 * theta + 316 * theta * theta;
  const Numeric   e2    = 3.52;  
  const Numeric   f2    = 39.8 * f1;
 
  for( Index iv=0; iv<nf; iv++ )
    { 
      const Complex  ifGHz( 0.0, f_grid[iv]/1e9 );
          
      Complex n = sqrt( e2 + (e1-e2) / (Numeric(1.0)-ifGHz/f2) + 
                          (e0-e1) / (Numeric(1.0)-ifGHz/f1) );
    
      complex_n(iv,0) = n.real();
      complex_n(iv,1) = n.imag();
    }
}
 
 
/* Workspace method: Doxygen documentation will be auto-generated */
void emissionPlanck(Vector&         emission,
                    const Vector&   f,
                    const Numeric&  t,
                    const Verbosity&)
{
  const Index   n = f.nelem();
 
  emission.resize(n);
 
  for( Index i=0; i<n; i++ )
    { emission[i] = planck( f[i], t ); }
}
 
 
/* Workspace method: Doxygen documentation will be auto-generated */
void MatrixCBR(// WS Output:
               Matrix&   m,
               // WS Input:
               const Index&    stokes_dim,
               // WS Generic Input:
               const Vector&   f,
               const Verbosity&)
{
  const Index n = f.nelem();
 
  if( n == 0 )
    throw runtime_error( "The given frequency vector is empty." );
 
  m.resize(n,stokes_dim);
  m = 0;
 
  for( Index i=0; i<n; i++ )
    { m(i,0) = planck( f[i], COSMIC_BG_TEMP ); }
}
 
 
/* Workspace method: Doxygen documentation will be auto-generated */
void MatrixPlanck(// WS Output:
                  Matrix&   m,
                  // WS Input:
                  const Index&    stokes_dim,
                  // WS Generic Input:
                  const Vector&   f,
                  const Numeric&  t,
                  const Verbosity& verbosity)
{
  CREATE_OUT2
  
  const Index n = f.nelem();
 
  if( n == 0 )
    throw runtime_error( "The given frequency vector is empty." );
 
  out2 << "  Setting blackbody radiation for a temperature of " << t << " K.\n";
 
  m.resize(n,stokes_dim);
  m = 0;
 
  for( Index i=0; i<n; i++ )
    { m(i,0) = planck( f[i], t ); }
}
 
 
 
 
/* Workspace method: Doxygen documentation will be auto-generated */
void MatrixUnitIntensity(// WS Output:
                         Matrix&   m,
                         // WS Input:
                         const Index&    stokes_dim,
                         // WS Generic Input:
                         const Vector&   f,
                         const Verbosity& verbosity)
{
  CREATE_OUT2
  
  const Index n = f.nelem();
 
  if( n == 0 )
    throw runtime_error( "The given frequency vector is empty." );
 
  out2 << "  Setting unpolarised radiation with an intensity of 1.\n";
 
  m.resize(n,stokes_dim);
  m = 0;
 
  for( Index i=0; i<n; i++ )
    { m(i,0) = 1.0; }
}