Пример #1
0
void smf_mapbounds( int fast, Grp *igrp,  int size, const char *system,
                    AstFrameSet *spacerefwcs, int alignsys, int *lbnd_out,
                    int *ubnd_out, AstFrameSet **outframeset, int *moving,
                    smfBox ** boxes, fts2Port fts_port, int *status ) {

  /* Local Variables */
  AstSkyFrame *abskyframe = NULL; /* Output Absolute SkyFrame */
  int actval;           /* Number of parameter values supplied */
  AstMapping *bolo2map = NULL; /* Combined mapping bolo->map
                                  coordinates, WCS->GRID Mapping from
                                  input WCS FrameSet */
  smfBox *box = NULL;          /* smfBox for current file */
  smfData *data = NULL;        /* pointer to  SCUBA2 data struct */
  double dlbnd[ 2 ];    /* Floating point lower bounds for output map */
  drcntrl_bits drcntrl_mask = 0;/* Mask to use for DRCONTROL on this instrument */
  double dubnd[ 2 ];    /* Floating point upper bounds for output map */
  AstMapping *fast_map = NULL; /* Mapping from tracking to absolute map coords */
  smfFile *file = NULL;        /* SCUBA2 data file information */
  int first;                   /* Is this the first good subscan ? */
  AstFitsChan *fitschan = NULL;/* Fits channels to construct WCS header */
  AstFrameSet *fs = NULL;      /* A general purpose FrameSet pointer */
  smfHead *hdr = NULL;         /* Pointer to data header this time slice */
  int i;                       /* Loop counter */
  dim_t j;                     /* Loop counter */
  AstSkyFrame *junksky = NULL; /* Unused SkyFrame argument */
  dim_t k;                     /* Loop counter */
  int lbnd0[ 2 ];              /* Defaults for LBND parameter */
  double map_pa=0;             /* Map PA in output coord system (rads) */
  dim_t maxloop;               /* Number of times to go round the time slice loop */
  dim_t nbadt  = 0;            /* Number of bad time slices */
  dim_t ngoodt = 0;            /* Number of good time slices */
  double par[7];               /* Projection parameters */
  double shift[ 2 ];           /* Shifts from PIXEL to GRID coords */
  AstMapping *oskymap = NULL;  /* Mapping celestial->map coordinates,
                                  Sky <> PIXEL mapping in output
                                  FrameSet */
  AstSkyFrame *oskyframe = NULL;/* Output SkyFrame */
  char *refsys = NULL;         /* Sky system from supplied reference FrameSet */
  dim_t textreme[4];           /* Time index corresponding to minmax TCS posn */
  AstFrame *skyin = NULL;      /* Sky Frame in input FrameSet */
  double skyref[ 2 ];          /* Values for output SkyFrame SkyRef attribute */
  struct timeval tv1;          /* Timer */
  struct timeval tv2;          /* Timer */
  AstMapping *tmap;            /* Temporary Mapping */
  int trim;                    /* Trim borders of bad pixels from o/p image? */
  int ubnd0[ 2 ];              /* Defaults for UBND parameter */
  double x_array_corners[4];   /* X-Indices for corner bolos in array */
  double x_map[4];             /* Projected X-coordinates of corner bolos */
  double y_array_corners[4];   /* Y-Indices for corner pixels in array */
  double y_map[4];             /* Projected X-coordinates of corner bolos */

  /* Main routine */
  if (*status != SAI__OK) return;

  /* Start a timer to see how long this takes */
  smf_timerinit( &tv1, &tv2, status );

  /* Initialize pointer to output FrameSet and moving-source flag */
  *outframeset = NULL;
  *moving = 0;

  /* initialize double precision output bounds and the proj pars */
  for( i = 0; i < 7; i++ ) par[ i ] = AST__BAD;
  dlbnd[ 0 ] = VAL__MAXD;
  dlbnd[ 1 ] = VAL__MAXD;
  dubnd[ 0 ] = VAL__MIND;
  dubnd[ 1 ] = VAL__MIND;

  /* If we have a supplied reference WCS we can use that directly
     without having to calculate it from the data. Replace the requested
     system with the system from the reference FrameSet (take a copy of the
     string since astGetC may re-use its buffer). */
  if (spacerefwcs) {
     oskyframe = astGetFrame( spacerefwcs, AST__CURRENT );
     int nc = 0;
     refsys = astAppendString( NULL, &nc, astGetC( oskyframe, "System" ) );
     system = refsys;
  }

  /* Create array of returned smfBox structures and store a pointer
     to the next one to be initialised. */
  *boxes = astMalloc( sizeof( smfBox ) * size );
  box = *boxes;

  astBegin;

  /* Loop over all files in the Grp */
  first = 1;
  for( i=1; i<=size; i++, box++ ) {

    /* Initialise the spatial bounds of section of the the output cube that is
       contributed to by the current ionput file. */
    box->lbnd[ 0 ] = VAL__MAXD;
    box->lbnd[ 1 ] = VAL__MAXD;
    box->ubnd[ 0 ] = VAL__MIND;
    box->ubnd[ 1 ] = VAL__MIND;

    /* Read data from the ith input file in the group */
    smf_open_file( NULL, igrp, i, "READ", SMF__NOCREATE_DATA, &data, status );

    if (*status != SAI__OK) {
      msgSeti( "I", i );
      errRep( "smf_mapbounds", "Could not open data file no ^I.", status );
      break;
    } else {
      if( *status == SAI__OK ) {
        if( data->file == NULL ) {
          *status = SAI__ERROR;
          errRep( FUNC_NAME, "No smfFile associated with smfData.",
                  status );
          break;

        } else if( data->hdr == NULL ) {
          *status = SAI__ERROR;
          errRep( FUNC_NAME, "No smfHead associated with smfData.",
                  status );
          break;

        } else if( data->hdr->fitshdr == NULL ) {
          *status = SAI__ERROR;
          errRep( FUNC_NAME, "No FITS header associated with smfHead.",
                  status );
          break;

        }
      }
    }

    /* convenience pointers */
    file = data->file;
    hdr = data->hdr;

    /* report name of the input file */
    smf_smfFile_msg( file, "FILE", 1, "<unknown>" );
    msgSeti("I", i);
    msgSeti("N", size);
    msgOutif(MSG__VERB, " ",
             "SMF_MAPBOUNDS: Processing ^I/^N ^FILE",
             status);

/* Check that there are 3 pixel axes. */
    if( data->ndims != 3 ) {
      smf_smfFile_msg( file, "FILE", 1, "<unknown>" );
      msgSeti( "NDIMS", data->ndims );
      *status = SAI__ERROR;
      errRep( FUNC_NAME, "^FILE has ^NDIMS pixel axes, should be 3.",
              status );
      break;
    }

    /* Check that the data dimensions are 3 (for time ordered data) */
    if( *status == SAI__OK ) {

      /* If OK Decide which detectors (GRID coord) to use for
         checking bounds, depending on the instrument in use. */

      switch( hdr->instrument ) {

      case INST__SCUBA2:
        drcntrl_mask = DRCNTRL__POSITION;
        /* 4 corner bolometers of the subarray */
        x_array_corners[0] = 1;
        x_array_corners[1] = 1;
        x_array_corners[2] = (data->dims)[0];
        x_array_corners[3] = (data->dims)[0];

        y_array_corners[0] = 1;
        y_array_corners[1] = (data->dims)[1];
        y_array_corners[2] = 1;
        y_array_corners[3] = (data->dims)[1];
        break;

      case INST__AZTEC:
        /* Rough guess for extreme bolometers around the edge */
        x_array_corners[0] = 22;
        x_array_corners[1] = 65;
        x_array_corners[2] = 73;
        x_array_corners[3] = 98;

        y_array_corners[0] = 1; /* Always 1 for AzTEC */
        y_array_corners[1] = 1;
        y_array_corners[2] = 1;
        y_array_corners[3] = 1;
        break;

      case INST__ACSIS:
        smf_find_acsis_corners( data, x_array_corners, y_array_corners,
                                status);
        break;

      default:
        *status = SAI__ERROR;
        errRep(FUNC_NAME, "Don't know how to calculate mapbounds for data created with this instrument", status);
      }
    }

    if( *status == SAI__OK) {
      size_t goodidx = SMF__BADSZT;

      /* Need to build up a frameset based on good telescope position.
         We can not assume that we the first step will be a good TCS position
         so we look for one. If we can not find anything we skip to the
         next file. */
      maxloop = (data->dims)[2];
      for (j=0; j<maxloop; j++) {
        JCMTState state = (hdr->allState)[j];
        if (state.jos_drcontrol >= 0 && state.jos_drcontrol & drcntrl_mask ) {
          /* bad TCS - so try again */
        } else {
          /* Good tcs */
          goodidx = j;
          break;
        }
      }

      if (goodidx == SMF__BADSZT) {
        smf_smfFile_msg( data->file, "FILE", 1, "<unknown>");
        msgOutif( MSG__QUIET, "", "No good telescope positions found in file ^FILE. Ignoring",
                  status );
        smf_close_file( NULL, &data, status );
        continue;
      }

      /* If we are dealing with the first good file, create the output
         SkyFrame. */
      if( first ) {
        first = 0;

        /* Create output SkyFrame if it has not come from a reference */
        if ( oskyframe == NULL ) {

          /* smf_tslice_ast only needs to get called once to set up framesets */
          if( hdr->wcs == NULL ) {
            smf_tslice_ast( data, goodidx, 1, fts_port, status);
          }

          /* Retrieve input SkyFrame */
          skyin = astGetFrame( hdr->wcs, AST__CURRENT );

          smf_calc_skyframe( skyin, system, hdr, alignsys, &oskyframe, skyref,
                             moving, status );

          /* Get the orientation of the map vertical within the output celestial
             coordinate system. This is derived form the MAP_PA FITS header, which
             gives the orientation of the map vertical within the tracking system. */
          map_pa = smf_calc_mappa( hdr, system, skyin, status );

          /* Provide a sensible default for the pixel size based on wavelength */
          par[4] = smf_calc_telres( hdr->fitshdr, status );
          par[4] *= AST__DD2R/3600.0;
          par[5] = par[4];

          /* Calculate the projection parameters. We do not enable autogrid determination
             for SCUBA-2 so we do not need to obtain all the data before calculating
             projection parameters. */
          smf_get_projpar( oskyframe, skyref, *moving, 0, 0, NULL, 0,
                           map_pa, par, NULL, NULL, status );

          if (skyin) skyin = astAnnul( skyin );

        /* If the output skyframe has been supplied, we still need to
           determine whether the source is moving or not, and set the
           reference position. */
        } else {

          /* smf_tslice_ast only needs to get called once to set up framesets */
          if( hdr->wcs == NULL ) {
            smf_tslice_ast( data, goodidx, 1, fts_port, status);
          }

          /* Retrieve input SkyFrame */
          skyin = astGetFrame( hdr->wcs, AST__CURRENT );
          smf_calc_skyframe( skyin, system, hdr, alignsys, &junksky, skyref,
                             moving, status );

          /* Store the sky reference position. If the target is moving,
             ensure the returned SkyFrame represents offsets from the
             reference position rather than absolute coords. */
          astSetD( oskyframe, "SkyRef(1)", skyref[ 0 ] );
          astSetD( oskyframe, "SkyRef(2)", skyref[ 1 ] );
          if( *moving ) astSet( oskyframe, "SkyRefIs=Origin" );

          /* Ensure the Epoch attribute in the map is set to the date of
             the first data in the map, rather than the date in supplied
             reference WCS. */
          astSetD( oskyframe, "Epoch", astGetD( junksky, "Epoch" ) );
        }

        if ( *outframeset == NULL && oskyframe != NULL && (*status == SAI__OK)){
          /* Now created a spatial Mapping. Use the supplied reference frameset
             if supplied */
          if (spacerefwcs) {
            oskymap = astGetMapping( spacerefwcs, AST__BASE, AST__CURRENT );
          } else {
            /* Now populate a FitsChan with FITS-WCS headers describing
               the required tan plane projection. The longitude and
               latitude axis types are set to either (RA,Dec) or (AZ,EL)
               to get the correct handedness. */
            fitschan = astFitsChan ( NULL, NULL, " " );
            smf_makefitschan( astGetC( oskyframe, "System"), &(par[0]),
                              &(par[2]), &(par[4]), par[6], fitschan, status );
            astClear( fitschan, "Card" );
            fs = astRead( fitschan );

            /* Extract the output PIXEL->SKY Mapping. */
            oskymap = astGetMapping( fs, AST__BASE, AST__CURRENT );

            /* Tidy up */
            fs = astAnnul( fs );
          }

          /* Create the output FrameSet */
          *outframeset = astFrameSet( astFrame(2, "Domain=GRID"), " " );

          /* Now add the SkyFrame to it */
          astAddFrame( *outframeset, AST__BASE, oskymap, oskyframe );

          /* Now add a POLANAL Frame if required (i.e. if the input time
             series are POL-2 Q/U values). */
          smf_addpolanal( *outframeset, hdr, status );

          /* Invert the oskymap mapping */
          astInvert( oskymap );

        } /* End WCS FrameSet construction */
      }

      /* Get a copy of the output SkyFrame and ensure it represents
         absolute coords rather than offset coords. */
      abskyframe = astCopy( oskyframe );
      astClear( abskyframe, "SkyRefIs" );
      astClear( abskyframe, "AlignOffset" );

      maxloop = (data->dims)[2];
      if (fast) {
        /* For scan map we scan through looking for largest telescope moves.
           For dream/stare we just look at the start and end time slices to
           account for sky rotation. */

        if (hdr->obsmode != SMF__OBS_SCAN) {
          textreme[0] = 0;
          textreme[1] = (data->dims)[2] - 1;
          maxloop = 2;

        } else {
          const char *tracksys;
          double *ac1list, *ac2list, *bc1list, *bc2list, *p1, *p2, *p3, *p4;
          double flbnd[4], fubnd[4];
          JCMTState state;

          /* If the output and tracking systems are different, get a
             Mapping between them. */
          tracksys = sc2ast_convert_system( (hdr->allState)[goodidx].tcs_tr_sys,
                                            status );
          if( strcmp( system, tracksys ) ) {
             AstSkyFrame *tempsf = astCopy( abskyframe );
             astSetC( tempsf, "System", tracksys );
             AstFrameSet *tempfs = astConvert( tempsf, abskyframe, "" );
             tmap = astGetMapping( tempfs, AST__BASE, AST__CURRENT );
             fast_map = astSimplify( tmap );
             tmap = astAnnul( tmap );
             tempsf = astAnnul( tempsf );
             tempfs = astAnnul( tempfs );
          } else {
             fast_map = NULL;
          }

          /* Copy all ac1/2 positions into two array, and transform them
             from tracking to absolute output sky coords. */
          ac1list = astMalloc( maxloop*sizeof( *ac1list ) );
          ac2list = astMalloc( maxloop*sizeof( *ac2list ) );
          if( *status == SAI__OK ) {
             p1 = ac1list;
             p2 = ac2list;
             for( j = 0; j < maxloop; j++ ) {
                state = (hdr->allState)[ j ];
                *(p1++) = state.tcs_tr_ac1;
                *(p2++) = state.tcs_tr_ac2;
             }
             if( fast_map ) astTran2( fast_map, maxloop, ac1list, ac2list, 1,
                                      ac1list, ac2list );
          }

          /* If the target is moving, we need to adjust these ac1/2 values
             to represent offsets from the base position. */
          if( *moving ) {

          /* Copy all bc1/2 positions into two arrays. */
             bc1list = astMalloc( maxloop*sizeof( *bc1list ) );
             bc2list = astMalloc( maxloop*sizeof( *bc2list ) );
             if( *status == SAI__OK ) {
                p1 = bc1list;
                p2 = bc2list;

                for( j = 0; j < maxloop; j++ ) {
                   state = (hdr->allState)[ j ];
                   *(p1++) = state.tcs_tr_bc1;
                   *(p2++) = state.tcs_tr_bc2;
                }

                /* Transform them from tracking to absolute output sky coords. */
                if( fast_map ) astTran2( fast_map, maxloop, bc1list, bc2list,
                                         1, bc1list, bc2list );

                /* Replace each ac1/2 position with the offsets from the
                   corresponding base position. */
                p1 = bc1list;
                p2 = bc2list;
                p3 = ac1list;
                p4 = ac2list;
                for( j = 0; j < maxloop; j++ ) {
                  smf_offsets( *(p1++), *(p2++), p3++, p4++, status );
                }
             }

             /* We no longer need the base positions. */
             bc1list = astFree( bc1list );
             bc2list = astFree( bc2list );
          }

          /* Transform the ac1/2 position from output sky coords to
             output pixel coords. */
          astTran2( oskymap, maxloop, ac1list, ac2list, 1, ac1list, ac2list );

          /* Find the bounding box containing these pixel coords and the
             time slices at which the boresight touches each edge of this
             box. */
          flbnd[ 0 ] = VAL__MAXD;
          flbnd[ 1 ] = VAL__MAXD;
          fubnd[ 0 ] = VAL__MIND;
          fubnd[ 1 ] = VAL__MIND;
          for( j = 0; j < 4; j++ ) textreme[ j ] = (dim_t) VAL__BADI;

          if( *status == SAI__OK ) {
             p1 = ac1list;
             p2 = ac2list;
             for( j = 0; j < maxloop; j++,p1++,p2++ ) {
                if( *p1 != VAL__BADD && *p2 != VAL__BADD ){

                   if ( *p1 < flbnd[0] ) { flbnd[0] = *p1; textreme[0] = j; }
                   if ( *p2 < flbnd[1] ) { flbnd[1] = *p2; textreme[1] = j; }
                   if ( *p1 > fubnd[0] ) { fubnd[0] = *p1; textreme[2] = j; }
                   if ( *p2 > fubnd[1] ) { fubnd[1] = *p2; textreme[3] = j; }
                }
             }
          }

          maxloop = 4;
          msgSetd("X1", textreme[0]);
          msgSetd("X2", textreme[1]);
          msgSetd("X3", textreme[2]);
          msgSetd("X4", textreme[3]);
          msgOutif( MSG__DEBUG, " ",
                    "Extrema time slices are ^X1, ^X2, ^X3 and ^X4",
                    status);

          ac1list = astFree( ac1list );
          ac2list = astFree( ac2list );

        }
      }

      /* Get the astrometry for all the relevant time slices in this data file */
      for( j=0; j<maxloop; j++ ) {
        dim_t ts;  /* Actual time slice to use */

        /* if we are doing the fast loop, we need to read the time slice
           index from textreme. Else we just use the index */
        if (fast) {
          /* get the index but make sure it is good */
          ts = textreme[j];
          if (ts == (dim_t)VAL__BADI) continue;
        } else {
          ts = j;
        }
        /* Calculate the bolo to map-pixel transformation for this tslice */
        bolo2map = smf_rebin_totmap( data, ts, abskyframe, oskymap,
                                     *moving, fts_port, status );

        if ( *status == SAI__OK ) {
          /* skip if we did not get a mapping this time round */
          if (!bolo2map) continue;

          /* Check corner pixels in the array for their projected extent
             on the sky to set the pixel bounds */
          astTran2( bolo2map, 4, x_array_corners, y_array_corners, 1,
                    x_map, y_map );

          /* Update min/max for this time slice */
          for( k=0; k<4; k++ ) {

            if( x_map[k] != AST__BAD && y_map[k] != AST__BAD ) {
              if( x_map[k] < dlbnd[0] ) dlbnd[0] = x_map[k];
              if( y_map[k] < dlbnd[1] ) dlbnd[1] = y_map[k];
              if( x_map[k] > dubnd[0] ) dubnd[0] = x_map[k];
              if( y_map[k] > dubnd[1] ) dubnd[1] = y_map[k];

              if( x_map[k] < box->lbnd[0] ) box->lbnd[0] = x_map[k];
              if( y_map[k] < box->lbnd[1] ) box->lbnd[1] = y_map[k];
              if( x_map[k] > box->ubnd[0] ) box->ubnd[0] = x_map[k];
              if( y_map[k] > box->ubnd[1] ) box->ubnd[1] = y_map[k];

            } else if( *status == SAI__OK ) {
              *status = SAI__ERROR;
              errRep( FUNC_NAME, "Extreme positions are bad.", status );
              break;
            }
          }
        }
        /* Explicitly annul these mappings each time slice for reduced
           memory usage */
        if (bolo2map) bolo2map = astAnnul( bolo2map );
        if (fs) fs = astAnnul( fs );

        /* Break out of loop over time slices if bad status */
        if (*status != SAI__OK) goto CLEANUP;
      }

      /* Annul any remaining Ast objects before moving on to the next file */
      if (fs) fs = astAnnul( fs );
      if (bolo2map) bolo2map = astAnnul( bolo2map );
    }

    /* Close the data file */
    smf_close_file( NULL, &data, status);

    /* Break out of loop over data files if bad status */
    if (*status != SAI__OK) goto CLEANUP;
  }

  /* make sure we got values - should not be possible with good status */
  if (dlbnd[0] == VAL__MAXD || dlbnd[1] == VAL__MAXD) {
    if (*status == SAI__OK) {
      *status = SAI__ERROR;
      errRep( " ", "Unable to find any valid map bounds", status );
    }
  }

  if (nbadt > 0) {
    msgOutf( "", "   Processed %zu time slices to calculate bounds,"
             " of which %zu had bad telescope data and were skipped",
             status, (size_t)(ngoodt+nbadt), (size_t)nbadt );
  }

  /* If spatial reference wcs was supplied, store par values that result in
     no change to the pixel origin. */
  if( spacerefwcs ){
    par[ 0 ] = 0.5;
    par[ 1 ] = 0.5;
  }

  /* Need to re-align with the interim GRID coordinates */
  lbnd_out[0] = ceil( dlbnd[0] - par[0] + 0.5 );
  ubnd_out[0] = ceil( dubnd[0] - par[0] + 0.5 );
  lbnd_out[1] = ceil( dlbnd[1] - par[1] + 0.5 );
  ubnd_out[1] = ceil( dubnd[1] - par[1] + 0.5 );

  /* Do the same with the individual input file bounding boxes */
  box = *boxes;
  for (i = 1; i <= size; i++, box++) {
    box->lbnd[0] = ceil( box->lbnd[0] - par[0] + 0.5);
    box->ubnd[0] = ceil( box->ubnd[0] - par[0] + 0.5);
    box->lbnd[1] = ceil( box->lbnd[1] - par[1] + 0.5);
    box->ubnd[1] = ceil( box->ubnd[1] - par[1] + 0.5);
  }

  /* Apply a ShiftMap to the output FrameSet to re-align the GRID
     coordinates */
  shift[0] = 2.0 - par[0] - lbnd_out[0];
  shift[1] = 2.0 - par[1] - lbnd_out[1];
  astRemapFrame( *outframeset, AST__BASE, astShiftMap( 2, shift, " " ) );

  /* Set the dynamic defaults for lbnd/ubnd */
  lbnd0[ 0 ] = lbnd_out[ 0 ];
  lbnd0[ 1 ] = lbnd_out[ 1 ];
  parDef1i( "LBND", 2, lbnd0, status );

  ubnd0[ 0 ] = ubnd_out[ 0 ];
  ubnd0[ 1 ] = ubnd_out[ 1 ];
  parDef1i( "UBND", 2, ubnd0, status );

  parGet1i( "LBND", 2, lbnd_out, &actval, status );
  if( actval == 1 ) lbnd_out[ 1 ] = lbnd_out[ 0 ];

  parGet1i( "UBND", 2, ubnd_out, &actval, status );
  if( actval == 1 ) ubnd_out[ 1 ] = ubnd_out[ 0 ];

  /* Ensure the bounds are the right way round. */
  if( lbnd_out[ 0 ] > ubnd_out[ 0 ] ) {
    int itmp = lbnd_out[ 0 ];
    lbnd_out[ 0 ] = ubnd_out[ 0 ];
    ubnd_out[ 0 ] = itmp;
  }

  if( lbnd_out[ 1 ] > ubnd_out[ 1 ] ) {
    int itmp = lbnd_out[ 1 ];
    lbnd_out[ 1 ] = ubnd_out[ 1 ];
    ubnd_out[ 1 ] = itmp;
  }

  /* If borders of bad pixels are being trimmed from the output image,
     then do not allow the user-specified bounds to extend outside the
     default bounding box (since we know that the default bounding box
     encloses all available data). */
  parGet0l( "TRIM", &trim, status );
  if( trim ) {
     if( lbnd_out[ 0 ] < lbnd0[ 0 ] ) lbnd_out[ 0 ] = lbnd0[ 0 ];
     if( lbnd_out[ 1 ] < lbnd0[ 1 ] ) lbnd_out[ 1 ] = lbnd0[ 1 ];
     if( ubnd_out[ 0 ] > ubnd0[ 0 ] ) ubnd_out[ 0 ] = ubnd0[ 0 ];
     if( ubnd_out[ 1 ] > ubnd0[ 1 ] ) ubnd_out[ 1 ] = ubnd0[ 1 ];
  }

  /* Modify the returned FrameSet to take account of the new pixel origin. */
  shift[ 0 ] = lbnd0[ 0 ] - lbnd_out[ 0 ];
  shift[ 1 ] = lbnd0[ 1 ] - lbnd_out[ 1 ];
  if( shift[ 0 ] != 0.0 || shift[ 1 ] != 0.0 ) {
    astRemapFrame( *outframeset, AST__BASE, astShiftMap( 2, shift, " " ) );
  }

/* Report the pixel bounds of the cube. */
  if( *status == SAI__OK ) {
    msgOutif( MSG__NORM, " ", " ", status );
    msgSeti( "XL", lbnd_out[ 0 ] );
    msgSeti( "YL", lbnd_out[ 1 ] );
    msgSeti( "XU", ubnd_out[ 0 ] );
    msgSeti( "YU", ubnd_out[ 1 ] );
    msgOutif( MSG__NORM, " ", "   Output map pixel bounds: ( ^XL:^XU, ^YL:^YU )",
              status );

    if( ( ubnd_out[ 0 ] - lbnd_out[ 0 ] + 1 ) > MAX_DIM ||
        ( ubnd_out[ 1 ] - lbnd_out[ 1 ] + 1 ) > MAX_DIM ) {
      *status = SAI__ERROR;
      errRep( "", FUNC_NAME ": The map is too big. Check your list of input "
              "data files does not include widely separated observations.",
              status );
    }
  }

  /* If no error has occurred, export the returned FrameSet pointer from the
     current AST context so that it will not be annulled when the AST
     context is ended. Otherwise, ensure a null pointer is returned. */
  if( *status == SAI__OK ) {
    astExport( *outframeset );
  } else {
    *outframeset = astAnnul( *outframeset );
  }

  msgOutiff( SMF__TIMER_MSG, "",
             "Took %.3f s to calculate map bounds",
             status, smf_timerupdate( &tv1, &tv2, status ) );

  /* Clean Up */
 CLEANUP:
  if (*status != SAI__OK) {
    errRep(FUNC_NAME, "Unable to determine map bounds", status);
  }
  if (oskymap) oskymap  = astAnnul( oskymap );
  if (bolo2map) bolo2map = astAnnul( bolo2map );
  if (fitschan) fitschan = astAnnul( fitschan );

  if( data != NULL )
    smf_close_file( NULL, &data, status );

  refsys = astFree( refsys );

  astEnd;

}
Пример #2
0
void smurf_calcqu( int *status ) {

    /* Local Variables: */
    AstFitsChan *fc;           /* Holds FITS headers for output NDFs */
    AstKeyMap *config;         /* Holds all cleaning parameters */
    AstKeyMap *dkpars;         /* Holds dark squid cleaning parameters */
    AstKeyMap *heateffmap = NULL; /* Heater efficiency data */
    AstKeyMap *sub_instruments;/* Indicates which instrument is being used */
    Grp *bgrp = NULL;          /* Group of base names for each chunk */
    Grp *igrp = NULL;          /* Group of input files */
    Grp *ogrp = NULL;          /* Group of output files  */
    Grp *sgrp = NULL;          /* Group of science files */
    HDSLoc *loci = NULL;       /* Locator for output I container file */
    HDSLoc *locq = NULL;       /* Locator for output Q container file */
    HDSLoc *locu = NULL;       /* Locator for output U container file */
    NdgProvenance *oprov;      /* Provenance to store in each output NDF */
    ThrWorkForce *wf;          /* Pointer to a pool of worker threads */
    char headval[ 81 ];        /* FITS header value */
    char ndfname[ 30 ];        /* Name of output Q or U NDF */
    char polcrd[ 81 ];         /* FITS 'POL_CRD' header value */
    char subarray[ 10 ];       /* Subarray name (e.g. "s4a", etc) */
    double angrot;             /* Angle from focal plane X axis to fixed analyser */
    double paoff;              /* WPLATE value corresponding to POL_ANG=0.0 */
    float arcerror;            /* Max acceptable error (arcsec) in one block */
    int block_end;             /* Index of last time slice in block */
    int block_start;           /* Index of first time slice in block */
    int dkclean;               /* Clean dark squids? */
    int fix;                   /* Fix the POL-2 triggering issue? */
    int iblock;                /* Index of current block */
    int iplace;                /* NDF placeholder for current block's I image */
    int ipolcrd;               /* Reference direction for waveplate angles */
    int maxsize;               /* Max no. of time slices in a block */
    int minsize;               /* Min no. of time slices in a block */
    int nc;                    /* Number of characters written to a string */
    int pasign;                /* +1 or -1 indicating sense of POL_ANG value */
    int qplace;                /* NDF placeholder for current block's Q image */
    int submean;               /* Subtract mean value from each time slice? */
    int uplace;                /* NDF placeholder for current block's U image */
    size_t ichunk;             /* Continuous chunk counter */
    size_t idx;                /* Subarray counter */
    size_t igroup;             /* Index for group of related input NDFs */
    size_t inidx;              /* Index into group of science input NDFs */
    size_t nchunk;             /* Number continuous chunks outside iter loop */
    size_t ssize;              /* Number of science files in input group */
    smfArray *concat = NULL;   /* Pointer to smfArray holding bolometer data */
    smfArray *darks = NULL;    /* dark frames */
    smfArray *dkarray = NULL;  /* Pointer to smfArray holding dark squid data */
    smfArray *flatramps = NULL;/* Flatfield ramps */
    smfData *data = NULL;      /* Concatenated data for one subarray */
    smfData *dkdata = NULL;    /* Concatenated dark squid data for one subarray */
    smfGroup *sgroup = NULL;   /* smfGroup corresponding to sgrp */

    /* Check inhereited status */
    if( *status != SAI__OK ) return;

    /* Start new AST and NDF contexts. */
    astBegin;
    ndfBegin();

    /* Find the number of cores/processors available and create a work force
       holding the same number of threads. */
    wf = thrGetWorkforce( thrGetNThread( SMF__THREADS, status ), status );

    /* Get a group of input files */
    kpg1Rgndf( "IN", 0, 1, "  Give more NDFs...", &igrp, &ssize, status );

    /* Get a group containing just the files holding science data. */
    smf_find_science( igrp, &sgrp, 0, NULL, NULL, 1, 1, SMF__NULL, &darks,
                      &flatramps, &heateffmap, NULL, status );

    /* Check we have at least once science file. */
    ssize = grpGrpsz( sgrp, status );
    if( ssize == 0 ) {
        msgOutif( MSG__NORM, " ", "All supplied input frames were DARK.",
                  status );
    } else {

        /* See if a correction should be made for the POL2 triggering issue. */
        parGet0l( "FIX", &fix, status );

        /* Create HDS container files to hold the output NDFs. */
        datCreat( "OUTQ", "CALCQU", 0, 0, status );
        datCreat( "OUTU", "CALCQU", 0, 0, status );

        /* Associate the locators with the structures. */
        datAssoc( "OUTQ", "WRITE", &locq, status );
        datAssoc( "OUTU", "WRITE", &locu, status );

        /* The I images are optional. */
        if( *status == SAI__OK ) {
            datCreat( "OUTI", "CALCQU", 0, 0, status );
            datAssoc( "OUTI", "WRITE", &loci, status );
            if( *status == PAR__NULL ) {
                errAnnul( status );
                loci = NULL;
            }
        }

        /* Group the input files so that all files within a single group have the
           same wavelength and belong to the same subscan of the same observation.
           Also identify chunks of data that are contiguous in time, and
           determine to which such chunk each group belongs. All this information
           is returned in a smfGroup structure ("*sgroup"). */
        smf_grp_related( sgrp, ssize, 1, 1, 0, NULL, NULL, NULL,
                         NULL, &sgroup, &bgrp, NULL, status );

        /* Obtain the number of contiguous chunks. */
        if( *status == SAI__OK ) {
            nchunk = sgroup->chunk[ sgroup->ngroups - 1 ] + 1;
        } else {
            nchunk = 0;
        }

        /* Indicate we have not yet found a value for the ARCERROR parameter. */
        arcerror = 0.0;

        /* Loop over all contiguous chunks */
        for( ichunk = 0; ichunk < nchunk && *status == SAI__OK; ichunk++ ) {

            /* Display the chunk number. */
            if( nchunk > 1 ) {
                msgOutiff( MSG__VERB, "", "   Doing chunk %d of %d.",
                           status, (int) ichunk + 1, (int) nchunk );
            }

            /* Concatenate the data within this contiguous chunk. This produces a
               smfArray ("concat") containing a smfData for each subarray present in
               the chunk. Each smfData holds the concatenated data for a single
               subarray. */
            smf_concat_smfGroup( wf, NULL, sgroup, darks, NULL, flatramps,
                                 heateffmap, ichunk, 1, 1, NULL, 0, NULL, NULL,
                                 0, 0, 0, &concat, NULL, status );

            /* Get a KeyMap holding values for the configuration parameters. Since we
               sorted by wavelength when calling smf_grp_related, we know that all
               smfDatas in the current smfArray (i.e. chunk) will relate to the same
               wavelength. Therefore we can use the same parameters for all smfDatas in
               the current smfArray. */
            sub_instruments = smf_subinst_keymap( SMF__SUBINST_NONE,
                                                  concat->sdata[ 0 ], NULL,
                                                  0, status );
            config = kpg1Config( "CONFIG", "$SMURF_DIR/smurf_calcqu.def",
                                 sub_instruments, status );
            sub_instruments = astAnnul( sub_instruments );


            /* Get the CALCQU specific parameters. */
            if( !astMapGet0I( config, "PASIGN", &pasign ) ) pasign = 1;
            msgOutiff( MSG__VERB, "", "PASIGN=%d", status, pasign );
            if( !astMapGet0D( config, "PAOFF", &paoff ) ) paoff = 0.0;
            msgOutiff( MSG__VERB, "", "PAOFF=%g", status, paoff );
            if( !astMapGet0D( config, "ANGROT", &angrot ) ) angrot = 90.0;
            msgOutiff( MSG__VERB, "", "ANGROT=%g", status, angrot );
            if( !astMapGet0I( config, "SUBMEAN", &submean ) ) submean = 0;
            msgOutiff( MSG__VERB, "", "SUBMEAN=%d", status, submean );

            /* See if the dark squids should be cleaned. */
            if( !astMapGet0I( config, "DKCLEAN", &dkclean ) ) dkclean = 0;

            /* If required, clean the dark squids now since we might need to use them to
               clean the bolometer data. */
            if( dkclean ) {

                /* Create a smfArray containing the dark squid data. For each one, store
                   a pointer to the main header so that smf_clean_smfArray can get at the
                   JCMTState information. */
                dkarray = smf_create_smfArray( status );
                for( idx = 0; idx < concat->ndat && *status == SAI__OK; idx++ ) {
                    data = concat->sdata[ idx ];
                    if( data && data->da && data->da->dksquid ) {
                        dkdata = data->da->dksquid;
                        dkdata->hdr = data->hdr;
                        smf_addto_smfArray( dkarray, dkdata, status );
                    }
                }

                /* Clean the smfArray containing the dark squid data. Use the "CLEANDK.*"
                   parameters. */
                (void) astMapGet0A( config, "CLEANDK", &dkpars );
                smf_clean_smfArray( wf, dkarray, NULL, NULL, NULL, dkpars, status );
                dkpars = astAnnul( dkpars );

                /* Nullify the header pointers so that we don't accidentally close any. */
                if( dkarray ) {
                    for( idx = 0; idx < dkarray->ndat; idx++ ) {
                        dkdata = dkarray->sdata[ idx ];
                        dkdata->hdr = NULL;
                    }

                    /* Free the smfArray holding the dark squid data, but do not free the
                       individual smfDatas within it. */
                    dkarray->owndata = 0;
                    smf_close_related( &dkarray, status );
                }
            }

            /* Now clean the bolometer data */
            smf_clean_smfArray( wf, concat, NULL, NULL, NULL, config, status );

            /* If required correct for the POL2 triggering issue. */
            if( fix ) smf_fix_pol2( wf, concat, status );

            /* Loop round each sub-array in the current contiguous chunk of data. */
            for( idx = 0; idx < concat->ndat && *status == SAI__OK; idx++ ) {
                data = concat->sdata[ idx ];

                /* Find the name of the subarray that generated the data. */
                smf_find_subarray( data->hdr, subarray, sizeof(subarray), NULL,
                                   status );

                /* Display the sub-array. */
                if( concat->ndat > 1 ) {
                    msgOutiff( MSG__VERB, "", "   Doing sub-array %s.",
                               status, subarray );
                }

                /* Create an empty provenance structure. Each input NDF that contributes
                   to the current chunk and array will be added as an ancestor to this
                   structure, which will later be stored in each output NDF created for
                   this chunk and array. */
                oprov = ndgReadProv( NDF__NOID, "SMURF:CALCQU", status );

                /* Indicate we do not yet have any FITS headers for the output NDFs */
                fc = NULL;

                /* Indicate we do not yet know the coordinate reference frame for the
                   half-waveplate angle. */
                polcrd[ 0 ] = 0;
                ipolcrd = 0;

                /* Go through the smfGroup looking for groups of related input NDFs that
                   contribute to the current chunk. */
                for( igroup = 0; igroup < sgroup->ngroups; igroup++ ) {
                    if( sgroup->chunk[ igroup ] == ichunk ) {

                        /* Get the integer index into the GRP group (sgrp) that holds the input NDFs.
                           This index identifies the input NDF that provides the data for the current
                           chunk and subarray. This assumes that the order in which smf_concat_smfGroup
                           stores arrays in the "concat" smfArray matches the order in which
                           smf_grp_related stores arrays within the sgroup->subgroups. */
                        inidx = sgroup->subgroups[ igroup ][ idx ];

                        /* Add this input NDF as an ancestor into the output provenance structure. */
                        smf_accumulate_prov( NULL, sgrp, inidx, NDF__NOID,
                                             "SMURF:CALCQU", &oprov, status );

                        /* Merge the FITS headers from the current input NDF into the FitsChan
                           that holds headers for the output NDFs. The merging retains only those
                           headers which have the same value in all input NDFs. */
                        smf_fits_outhdr( data->hdr->fitshdr, &fc, status );

                        /* Get the polarimetry related FITS headers and check that all input NDFs
                           have usabie values. */
                        headval[ 0 ] = 0;
                        smf_getfitss( data->hdr, "POL_MODE", headval,
                                      sizeof(headval), status );
                        if( strcmp( headval, "CONSTANT" ) && *status == SAI__OK ) {
                            *status = SAI__ERROR;
                            grpMsg( "N", sgrp, inidx );
                            errRep( " ", "Input NDF ^N does not contain "
                                    "polarimetry data obtained with a spinning "
                                    "half-waveplate.", status );
                        }

                        headval[ 0 ] = 0;
                        smf_getfitss( data->hdr, "POLWAVIN", headval,
                                      sizeof(headval), status );
                        if( strcmp( headval, "Y" ) && *status == SAI__OK ) {
                            *status = SAI__ERROR;
                            grpMsg( "N", sgrp, inidx );
                            errRep( " ", "Half-waveplate was not in the beam for "
                                    "input NDF ^N.", status );
                        }

                        headval[ 0 ] = 0;
                        smf_getfitss( data->hdr, "POLANLIN", headval,
                                      sizeof(headval), status );
                        if( strcmp( headval, "Y" ) && *status == SAI__OK ) {
                            *status = SAI__ERROR;
                            grpMsg( "N", sgrp, inidx );
                            errRep( " ", "Analyser was not in the beam for input "
                                    "NDF ^N.", status );
                        }

                        if( polcrd[ 0 ] ) {
                            headval[ 0 ] = 0;
                            smf_getfitss( data->hdr, "POL_CRD", headval,
                                          sizeof(headval), status );
                            if( strcmp( headval, polcrd ) && *status == SAI__OK ) {
                                *status = SAI__ERROR;
                                errRep( " ", "Input NDFs have differing values for "
                                        "FITS header 'POL_CRD'.", status );
                            }

                        } else {
                            smf_getfitss( data->hdr, "POL_CRD", polcrd,
                                          sizeof(polcrd), status );
                            if( !strcmp( polcrd, "FPLANE" ) ) {
                                ipolcrd = 0;
                            } else if( !strcmp( polcrd, "AZEL" ) ) {
                                ipolcrd = 1;
                            } else if( !strcmp( polcrd, "TRACKING" ) ) {
                                ipolcrd = 2;
                            } else if( *status == SAI__OK ) {
                                *status = SAI__ERROR;
                                msgSetc( "N", data->file->name );
                                msgSetc( "V", polcrd );
                                errRep( " ", "Input NDF ^N contains unknown value "
                                        "'^V' for FITS header 'POL_CRD'.", status );
                            }
                        }
                    }
                }

                /* If not already done, get the maximum spatial drift (in arc-seconds) that
                   can be tolerated whilst creating a single I/Q/U image. The default value is
                   half the makemap default pixel size. Also get limits on the number of
                   time slices in any block. */
                if( arcerror == 0.0 ) {
                    parDef0d( "ARCERROR", 0.5*smf_calc_telres( data->hdr->fitshdr,
                              status ), status );
                    parGet0r( "ARCERROR", &arcerror, status );

                    parGet0i( "MAXSIZE", &maxsize, status );
                    parGet0i( "MINSIZE", &minsize, status );
                    if( maxsize > 0 && maxsize < minsize && *status == SAI__OK ) {
                        *status = SAI__ERROR;
                        errRepf( "", "Value of parameter MAXSIZE (%d) is less "
                                 "than value of parameter MINSIZE (%d)", status,
                                 maxsize, minsize );
                    }
                }

                /* The algorithm that calculates I, Q and U assumes that all samples for a
                   single bolometer measure flux from the same point on the sky. Due to
                   sky rotation, this will not be the case - each bolometer will drift
                   slowly across the sky. However, since the drift is (or should be)
                   slow we can apply the I/Q/U algorithm to blocks of contiguous data over
                   which the bolometers do not move significantly. We produce a separate
                   I, Q and U image for each such block. The first block starts at the first
                   time slice in the smfData. */
                block_start = 0;

                /* Find the time slice at which the corner bolometers have moved
                   a critical distance (given by parameter ARCERROR) from their
                   positions at the start of the block. Then back off some time slices
                   to ensure that the block holds an integral number of half-waveplate
                   rotations. */
                block_end = smf_block_end( data, block_start, ipolcrd, arcerror,
                                           maxsize, status );

                /* Loop round creating I/Q/U images for each block. Count them. */
                iblock = 0;
                while( block_end >= 0 && *status == SAI__OK ) {

                    /* Skip very short blocks. */
                    if( block_end - block_start > minsize ) {

                        /* Display the start and end of the block. */
                        msgOutiff( MSG__VERB, "", "   Doing time slice block %d "
                                   "-> %d", status, (int) block_start,
                                   (int) block_end );

                        /* Get the name for the Q NDF for this block. Start of with "Q" followed by
                           the block index. */
                        iblock++;
                        nc = sprintf( ndfname, "Q%d", iblock );

                        /* Append the subarray name to the NDF name. */
                        nc += sprintf( ndfname + nc, "_%s", subarray );

                        /* Append the chunk index to the NDF name. */
                        nc += sprintf( ndfname + nc, "_%d", (int) ichunk );

                        /* Get NDF placeholder for the Q NDF. The NDFs are created inside the
                           output container file. */
                        ndfPlace( locq, ndfname, &qplace, status );

                        /* The name of the U NDF is the same except the initial "Q" is changed to
                           "U". */
                        ndfname[ 0 ] = 'U';
                        ndfPlace( locu, ndfname, &uplace, status );

                        /* The name of the I NDF is the same except the initial "Q" is changed to
                           "I". */
                        if( loci ) {
                            ndfname[ 0 ] = 'I';
                            ndfPlace( loci, ndfname, &iplace, status );
                        } else {
                            iplace = NDF__NOPL;
                        }

                        /* Store the chunk and block numbers as FITS headers. */
                        atlPtfti( fc, "POLCHUNK", (int) ichunk, "Chunk index used by CALCQU", status );
                        atlPtfti( fc, "POLBLOCK", iblock, "Block index used by CALCQU", status );

                        /* Create the Q and U images for the current block of time slices from
                           the subarray given by "idx", storing them in the output container
                           file. */
                        smf_calc_iqu( wf, data, block_start, block_end, ipolcrd,
                                      qplace, uplace, iplace, oprov, fc,
                                      pasign, AST__DD2R*paoff, AST__DD2R*angrot,
                                      submean, status );

                        /* Warn about short blocks. */
                    } else {
                        msgOutiff( MSG__VERB, "", "   Skipping short block of %d "
                                   "time slices (parameter MINSIZE=%d).", status,
                                   block_end - block_start - 1, minsize );
                    }

                    /* The next block starts at the first time slice following the previous
                       block. */
                    block_start = block_end + 1;

                    /* Find the time slice at which the corner bolometers have moved
                       a critical distance (given by parameter ARCERROR) from their
                       positions at the start of the block. Then back off some time slices
                       to ensure that the block holds an integral number of half-waveplate
                       rotations. This returns -1 if all time slices have been used. */
                    block_end = smf_block_end( data, block_start, ipolcrd,
                                               arcerror, maxsize, status );
                }

                /* Free resources */
                oprov = ndgFreeProv( oprov, status );
                fc = astAnnul( fc );
            }
            config = astAnnul( config );

            /* Close the smfArray. */
            smf_close_related( &concat, status );
        }

        /* Annul the locators for the output container files. */
        datAnnul( &locq, status );
        datAnnul( &locu, status );
        if( loci ) datAnnul( &loci, status );

        /* The parameter system hangs onto a primary locator for each container
           file, so cancel the parameters to annul these locators. */
        datCancl( "OUTQ", status );
        datCancl( "OUTU", status );
        datCancl( "OUTI", status );
    }

    /* Free resources. */
    smf_close_related( &darks, status );
    smf_close_related( &flatramps, status );

    if( igrp ) grpDelet( &igrp, status);
    if( sgrp ) grpDelet( &sgrp, status);
    if( bgrp ) grpDelet( &bgrp, status );
    if( ogrp ) grpDelet( &ogrp, status );
    if( sgroup ) smf_close_smfGroup( &sgroup, status );
    if (heateffmap) heateffmap = smf_free_effmap( heateffmap, status );

    /* End the NDF and AST contexts. */
    ndfEnd( status );
    astEnd;

    /* Issue a status indication.*/
    if( *status == SAI__OK ) {
        msgOutif( MSG__VERB, " ", "CALCQU succeeded.", status);
    } else {
        msgOutif( MSG__VERB, " ", "CALCQU failed.", status);
    }
}
Пример #3
0
void smf_mapbounds_approx( Grp *igrp,  size_t index, char *system,
			   int *lbnd_out, int *ubnd_out, AstFrameSet **outframeset,
			   int *moving, int *status ) {

  /* Local variables */
  smfData *data = NULL;        /* pointer to  SCUBA2 data struct */
  int dxpix;                   /* Map X offset in pixels */
  int dypix;                   /* Map Y offset in pixels */
  smfFile *file = NULL;        /* SCUBA2 data file information */
  AstFitsChan *fitschan = NULL;/* Fits channels to construct WCS header */
  AstFrameSet *fs = NULL;      /* A general purpose FrameSet pointer */
  smfHead *hdr = NULL;         /* Pointer to data header this time slice */
  double hghtbox;              /* Map height in arcsec */
  int hghtpix;                 /* RA-Dec map height in pixels */
  int i;                       /* loop counter */
  dim_t k;                     /* Loop counter */
  double maphght = 0.0;        /* Map height in radians */
  double mappa = 0.0;          /* Map position angle in radians */
  double mapwdth = 0.0;        /* Map width in radians */
  double mapx;                 /* Map X offset in radians */
  double mapy;                 /* Map Y offset in radians */
  double par[7];               /* Projection parameters */
  double pixsize = 0.0;        /* Requested pixel size */
  double shift[ 2 ];           /* Shifts from PIXEL to GRID coords */
  AstMapping *sky2map = NULL;  /* Mapping celestial->map coordinates */
  AstSkyFrame *skyframe = NULL;/* Output SkyFrame */
  AstFrame *skyin = NULL;      /* Sky Frame in input FrameSet */
  double skyref[ 2 ];          /* Values for output SkyFrame SkyRef attribute */
  AstFrameSet *swcsin = NULL;  /* FrameSet describing input WCS */
  int temp;                    /* Temporary variable  */
  double wdthbox;              /* Map width in arcsec */
  int wdthpix;                 /* RA-Dec map width in pixels */
  double x_array_corners[4];   /* X-Indices for corner bolos in array */
  double y_array_corners[4];   /* Y-Indices for corner pixels in array */

  /* Main routine */
  if (*status != SAI__OK) return;

  /* Begin an AST context to ensure that all AST objects are annuled
     before returning to caller */
  astBegin;

  /* Initialize output frameset pointer to NULL */
  *outframeset = NULL;
  for( i = 0; i < 7; i++ ) par[ i ] = AST__BAD;

  /* Read data from the given input file in the group - note index
     should be 1 as we use the first file in the Grp to define the map
     bounds */
  smf_open_file( igrp, index, "READ", SMF__NOCREATE_DATA, &data, status );

  /* Simply abort if it is not a scan */
  if (*status == SAI__OK && data->hdr->obsmode != SMF__OBS_SCAN) {
    *status = SAI__ERROR;
    errRep(" ", "Can not call smf_mapbounds_approx with non-scan observation"
           " (possible programming error)", status);
    goto CLEANUP;
  }

  /* Retrieve file name for use feedback */
  file = data->file;
  smf_smfFile_msg( file, "FILE", 1, "<unknown>" );
  if( *status == SAI__OK ) {
    msgOutif(MSG__VERB, " ",
	     "SMF_MAPBOUNDS_APPROX: Processing ^FILE",
	     status);
  } else {
    errRep( "smf_mapbounds_approx", "Couldn't open input file, ^FILE", status );
  }

  /* Check that the data dimensions are 3 (for time ordered data) */
  if( *status == SAI__OK ) {
    if( data->ndims != 3 ) {
      smf_smfFile_msg( file, "FILE", 1, "<unknown>" );
      msgSeti("THEDIMS", data->ndims);
      *status = SAI__ERROR;
      errRep("smf_mapbounds_approx",
	     "^FILE data has ^THEDIMS dimensions, should be 3.",
	     status);
    }
  }

  /* Construct the WCS for the first time slice in this file */
  smf_tslice_ast( data, 1, 1, NO_FTS, status);

  /* Retrieve header for later constructing output WCS */
  if( *status == SAI__OK) {
    hdr = data->hdr;
    swcsin = hdr->wcs;

    /* Calculate default pixel size */
    pixsize = smf_calc_telres( hdr->fitshdr, status );

    /* Get the user defined pixel size - we trust that smf_get_projpar will
       also read PIXSIZE and get the same answer. We pre-fill par[] to allow
       PIXSIZE=! to accept the dynamic default in both places.*/
    parGdr0d( "PIXSIZE", pixsize, 0, 60, 1, &pixsize, status );
    par[4] = pixsize*AST__DD2R/3600.0;
    par[5] = par[4];

    /* Retrieve input SkyFrame */
    skyin = astGetFrame( swcsin, AST__CURRENT );

    /* Retrieve map height and width from header - will be undef for
       non-scan so set up defaults first. */
    mapwdth = 0.0;
    maphght = 0.0;
    smf_getfitsd( hdr, "MAP_WDTH", &mapwdth, status );
    smf_getfitsd( hdr, "MAP_HGHT", &maphght, status );

    /* Make an approximation if map height and width are not set -
       note that this should ONLY apply for non-scan mode data */
    if ( !mapwdth || !maphght ) {
      if (*status == SAI__OK) {
        *status = SAI__ERROR;
        errRep(" ", "MAP_WDTH and MAP_HGHT must be > 0", status);
        goto CLEANUP;
      }
    }

    mapx = 0.0;   /* Used if the FITS keyword values are undefed */
    mapy = 0.0;
    smf_getfitsd( hdr, "MAP_X", &mapx, status );
    smf_getfitsd( hdr, "MAP_Y", &mapy, status );

    /* Convert map Position Angle to radians */
    mappa = 0.0;
    smf_fits_getD( hdr, "MAP_PA", &mappa, status );
    mappa *= AST__DD2R;

    /* Calculate size of output map in pixels */
    /* Note: this works for the simulator... */
    wdthbox = mapwdth*fabs(cos(mappa)) + maphght*fabs(sin(mappa));
    hghtbox = maphght*fabs(cos(mappa)) + mapwdth*fabs(sin(mappa));
    wdthpix = (int) ( wdthbox / pixsize);
    hghtpix = (int) ( wdthbox / pixsize);
    dxpix = (int) (mapx / pixsize);
    dypix = (int) (mapy / pixsize);

    /* Get the offsets for each corner of the array */
    temp = (wdthpix - 1) / 2;
    x_array_corners[0] = dxpix - temp;
    x_array_corners[1] = dxpix - temp;
    x_array_corners[2] = dxpix + temp;
    x_array_corners[3] = dxpix + temp;

    temp = (hghtpix - 1) / 2;
    y_array_corners[0] = dypix - temp;
    y_array_corners[1] = dypix + temp;
    y_array_corners[2] = dypix - temp;
    y_array_corners[3] = dypix + temp;

    lbnd_out[0] = x_array_corners[0];
    ubnd_out[0] = x_array_corners[0];
    lbnd_out[1] = y_array_corners[0];
    ubnd_out[1] = y_array_corners[0];

    /* Update min/max  */
    for( k=0; k<4; k++ ) {
      if( x_array_corners[k] < lbnd_out[0] ) lbnd_out[0] = x_array_corners[k];
      if( y_array_corners[k] < lbnd_out[1] ) lbnd_out[1] = y_array_corners[k];
      if( x_array_corners[k] > ubnd_out[0] ) ubnd_out[0] = x_array_corners[k];
      if( y_array_corners[k] > ubnd_out[1] ) ubnd_out[1] = y_array_corners[k];
    }

  } else {
    goto CLEANUP;
  }

  /* Now create the output FrameSet. */
  smf_calc_skyframe( skyin, system, hdr, 0, &skyframe, skyref, moving,
                     status );

  /* Get the orientation of the map vertical within the output celestial
     coordinate system. This is derived form the MAP_PA FITS header, which
     gives the orientation of the map vertical within the tracking system. */
  mappa = smf_calc_mappa( hdr, system, skyin, status );

  /* Calculate the projection parameters. We do not enable autogrid determination
     for SCUBA-2 so we do not need to obtain all the data before calculating
     projection parameters. */
  smf_get_projpar( skyframe, skyref, *moving, 0, 0, NULL, 0,
                   mappa, par, NULL, NULL, status );



  /* Now populate a FitsChan with FITS-WCS headers describing the
     required tan plane projection. The longitude and latitude axis
     types are set to either (RA,Dec) or (AZ,EL) to get the correct
     handedness. */
  fitschan = astFitsChan ( NULL, NULL, " " );
  smf_makefitschan( astGetC( skyframe, "System"), &(par[0]),
                    &(par[2]), &(par[4]), par[6], fitschan, status );
  astClear( fitschan, "Card" );
  fs = astRead( fitschan );

  /* Extract the output PIXEL->SKY Mapping - note this is will be
     inverted later to create the sk2map mapping */
  sky2map = astGetMapping( fs, AST__BASE, AST__CURRENT );

  /* Create the output FrameSet */
  *outframeset = astFrameSet( astFrame(2, "Domain=GRID"), " " );

  /* Now add the SkyFrame to it */
  astAddFrame( *outframeset, AST__BASE, sky2map, skyframe );

  /* Apply a ShiftMap to the output FrameSet to re-align the GRID
     coordinates */
  shift[0] = -lbnd_out[0];
  shift[1] = -lbnd_out[1];
  astRemapFrame( *outframeset, AST__BASE, astShiftMap( 2, shift, " " ) );

  astExport( *outframeset );

/* Report the pixel bounds of the cube. */
   if( *status == SAI__OK ) {
      msgOutif( MSG__NORM, " ", " ", status );
      msgSeti( "XL", lbnd_out[ 0 ] );
      msgSeti( "YL", lbnd_out[ 1 ] );
      msgSeti( "XU", ubnd_out[ 0 ] );
      msgSeti( "YU", ubnd_out[ 1 ] );
      msgOutif( MSG__NORM, " ", "   Output map pixel bounds: ( ^XL:^XU, ^YL:^YU )",
                status );
   }


  /* Change the pixel bounds to be consistent with the new CRPIX */
  ubnd_out[0] -= lbnd_out[0]-1;
  lbnd_out[0] = 1;

  ubnd_out[1] -= lbnd_out[1]-1;
  lbnd_out[1] = 1;

  /* Clean Up */
 CLEANUP:
  if (*status != SAI__OK) {
    errRep(FUNC_NAME, "Unable to determine map bounds", status);
  }

  if( data != NULL )
    smf_close_file( &data, status);

  astEnd;

}