/disk01/web/ocssw/build/src/viirs_sim_sdr/rhos_to_lt.c (r8102/r5074)

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#include "viirs_sim_sdr.h"
#include "l12_parms.h"
/*#include "l12_proto.h"  - Again, if we get the make more like ocssw 
   and maybe also need to move formally to that area */

int rhos_to_lt( int rhos_opt, float **rhos, in_rec_struc *in_rec, int idet, 
  sdr_info_struc *sdr_info )
/*-----------------------------------------------------------------------------
    Program:   rhos_to_lt

    Description:  convert the reflectance into Lt value and replace
      the Lt conditionally for a line in a scan of lines

    Arguments:
        Type      Name         I/O   Description
        ----      ----         ---   -----------
        int       rhos_opt      I    reflectance use option: 0 - replace 
                                     where Lt from ocean color is missing
                                     1 - replace everywhere
        float **  rhos          I    a scan's worth of reflectance
        in_rec_struc *  in_rec  I/O  input record structure with input values
                                     of atmospheric values and output of 
                                     final lt for simulated scan
        int       idet          I    line in scan to process
        sdr_info_struc * sdr_info I  general SDR information

    Modification history:

    W. Robinson, SAIC  18 Nov 2009  Original development
    W. Robinson, SAIC  12 Apr 2011  for a reflectance that is missing -999.
                or just < 0., set the bnd_q = 2

----------------------------------------------------------------------------*/
  {
  int ipx, npix, ibnd, repl, loc;
  float lt[N_VNIR_BND], solz, senz, mu, mu0;
  float tg_sol, tg_sen, t_sol, t_sen, t_h2o, t_o2, lr, refl;
 /*  positions of parameter fields in the l2 record, see rd_sim_init */
  int loc_tg_sol = N_VNIR_BND * 2, loc_tg_sen = N_VNIR_BND * 3; 
  int loc_t_sol = N_VNIR_BND * 4, loc_t_sen = N_VNIR_BND * 5;
  int loc_t_h2o = N_VNIR_BND * 6, loc_t_o2 = N_VNIR_BND * 7;
  int loc_lr = N_VNIR_BND;

  npix = in_rec->npix;
 /*
  *  get lt from rhos for all pixels and lines in the scan
  */
  for( ipx = 0; ipx < npix; ipx++ )
    {
    loc = ipx + idet * npix;
    solz = *( in_rec->solz + loc );
    senz = *( in_rec->senz + loc );
    mu0 = cos( solz / RADEG );
    mu = cos( senz / RADEG );
  
   /*
    *  derive the Lt for each band
    */
    for( ibnd = 0; ibnd < N_VNIR_BND; ibnd++ )
      {
      refl = *( *rhos + ipx + ( idet + ibnd * in_rec->ndet_scan ) * npix );
      if( refl < 0. )
        lt[ibnd] = -999.;
      else
        {
        t_h2o = *( in_rec->l2_str.l2_data + ( loc_t_h2o + ibnd ) * npix + ipx );
        lr = *( in_rec->l2_str.l2_data + ( loc_lr + ibnd ) * npix + ipx );
        t_sen = *( in_rec->l2_str.l2_data + ( loc_t_sen + ibnd ) * npix + ipx );
        t_sol = *( in_rec->l2_str.l2_data + ( loc_t_sol + ibnd ) * npix + ipx );
        t_o2 = *( in_rec->l2_str.l2_data + ( loc_t_o2 + ibnd ) * npix + ipx );
        tg_sen = *( in_rec->l2_str.l2_data + 
          ( loc_tg_sen + ibnd ) * npix + ipx );
        tg_sol = *( in_rec->l2_str.l2_data + 
          ( loc_tg_sol + ibnd ) * npix + ipx );
        
        lt[ibnd] = tg_sol * tg_sen * 
           ( refl * in_rec->f0[ibnd] * mu0 * t_sol * t_sen * t_o2 /PI + 
           RAD_CGS_2_MKS *lr );
        }
      }
   /*
    *  examine all the ocean lt and decide on replacing it with the lt(rhos)
    *  Options are to replace if Lt < 0 or a bad value (rhos_opt=0)
    *  or replace al points (rhos_opt=1)
    */
    if( rhos_opt == 1 )
      repl = 1;
    else
      {
      repl = 0;
      for( ibnd = 0; ibnd < N_VNIR_BND; ibnd++ )
        {
        if( ( *( in_rec->bnd_lt[ibnd] + loc ) < 0. ) ||
            ( *( in_rec->bnd_q[ibnd] + loc ) == 2 ) )
          {
          repl = 1;
          break;
          }
        }
     /*
      *  now, assume all reflectance is good and fill
      */
      if( repl == 1 )
        for( ibnd = 0; ibnd < N_VNIR_BND; ibnd++ )
          {
          if( lt[ibnd] < -0.5 )
            {
            *( in_rec->bnd_lt[ibnd] + loc ) = 0.;
            *( in_rec->bnd_q[ibnd] + loc ) = 2;
            }
          else
            {
            *( in_rec->bnd_lt[ibnd] + loc ) = lt[ibnd];
            *( in_rec->bnd_q[ibnd] + loc ) = 0;
            }
          }
      }
    }
  return 0;
  }