obs2spec.c

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/*
  This file is part of JURASSIC.
  
  JURASSIC 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 3 of the License, or
  (at your option) any later version.
  
  JURASSIC 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 JURASSIC. If not, see <http://www.gnu.org/licenses/>.
  
  Copyright (C) 2003-2026 Forschungszentrum Juelich GmbH
*/
 
#include <omp.h>
#include "jurassic.h"
 
/* ------------------------------------------------------------
   Functions...
   ------------------------------------------------------------ */
 
static void usage(
  void);
 
/* ------------------------------------------------------------
   Main...
   ------------------------------------------------------------ */
 
int main(
  int argc,
  char *argv[]) {
 
  static ctl_t ctl;
 
  obs_t *obs;
 
  FILE *out;
 
  /* Print usage information... */
  USAGE;
 
  /* Check arguments... */
  if (argc < 4)
    ERRMSG("Missing or invalid command-line arguments.\n\n"
           "Usage: obs2spec <ctl> <obs> <spec.tab> [KEY VALUE ...]\n\n"
           "Use -h for full help.");
 
  /* Allocate... */
  ALLOC(obs, obs_t, 1);
 
  /* Read control parameters... */
  read_ctl(argc, argv, &ctl);
 
  /* Read observation geometry... */
  read_obs(NULL, argv[2], &ctl, obs, 0);
 
  /* Write info... */
  LOG(1, "Write spectra: %s", argv[3]);
 
  /* Create file... */
  if (!(out = fopen(argv[3], "w")))
    ERRMSG("Cannot create file!");
 
  /* Write header... */
  fprintf(out,
          "# $1 = time (seconds since 2000-01-01T00:00Z)\n"
          "# $2 = observer altitude [km]\n"
          "# $3 = observer longitude [deg]\n"
          "# $4 = observer latitude [deg]\n"
          "# $5 = view point altitude [km]\n"
          "# $6 = view point longitude [deg]\n"
          "# $7 = view point latitude [deg]\n"
          "# $8 = tangent point altitude [km]\n"
          "# $9 = tangent point longitude [deg]\n"
          "# $10 = tangent point latitude [deg]\n"
          "# $11 = channel frequency [cm^-1]\n"
          "# $12 = channel radiance [W/(m^2 sr cm^-1)]\n"
          "# $13 = channel transmittance [1]\n");
 
  /* Write data... */
  for (int ir = 0; ir < obs->nr; ir++) {
    fprintf(out, "\n");
    for (int id = 0; id < ctl.nd; id++)
      fprintf(out, "%.2f %g %g %g %g %g %g %g %g %g %.4f %g %g\n",
              obs->time[ir], obs->obsz[ir], obs->obslon[ir], obs->obslat[ir],
              obs->vpz[ir], obs->vplon[ir], obs->vplat[ir], obs->tpz[ir],
              obs->tplon[ir], obs->tplat[ir], ctl.nu[id], obs->rad[id][ir],
              obs->tau[id][ir]);
  }
 
  /* Close file... */
  fclose(out);
 
  /* Free... */
  free(obs);
 
  return EXIT_SUCCESS;
}
 
/*****************************************************************************/
 
static void usage(
  void) {
  printf("\nJURASSIC spectrum writer.\n\n");
  printf("Write radiances and transmittances from an observation file to\n");
  printf("a per-channel spectrum table.\n\n");
  printf("Usage:\n");
  printf("  obs2spec <ctl> <obs> <spec.tab> [KEY VALUE ...]\n\n");
  printf("Arguments:\n");
  printf("  <ctl>       Control file.\n");
  printf("  <obs>       Observation input file.\n");
  printf("  <spec.tab>  Output spectrum table.\n");
  printf("  [KEY VALUE]  Optional control parameters.\n\n");
  printf("Common control parameters:\n");
  printf
    ("  OBSFMT                 Observation file format from the control file.\n");
  printf
    ("  ND, NU[i]              Spectral channels in observation files.\n");
  printf("  WRITE_BBT              Brightness-temperature output flag.\n\n");
  printf("Further information:\n");
  printf("  Manual: https://slcs-jsc.github.io/jurassic/\n");
}