DSS Pleiades Mosaic How-To

DSS pleiades mosaic

The bash script below, courtesy of Inseok Song (U. Georgia), uses Montage v3.0 to create a mosaic of the Pleiades from online Digitized Sky Survey (DSS2) data.

Relevant DSS2 FITS files are downloaded automatically through mArchiveList and mArchiveExec commands of the Montage package. Downloaded files are mosaicked into a 3x3 degree image via mProjExec and mAdd commands. Three large images are then put together as a false color image through the mJPEG command, where DSS2B/DSS2R/DSS2IR data are represented as blue/green/red, respectively. A gaussian-log image scale is used with a valid data range between -1 sigma and 99.999% of the maximum image value.

To create your own image, you must create your own image definition file (e.g. pleiades.hdr), and change the center position and size of your image in the mArchiveList command below.

For more information, contact the Montage Help Desk.

Contents of pleiades.bash

  # Pleiades Image creation BASH script.
  # Inseok Song, 2007
  for bands in DSS2B DSS2R DSS2IR; do echo Processing ${bands};
  mkdir $bands;
  cd $bands;
  mkdir raw projected;
  cd raw;
  mArchiveList dss ${bands} "56.5 23.75" 3 3 remote.tbl;
  mArchiveExec remote.tbl;
  cd .. ;
  mImgtbl raw rimages.tbl ;
  mProjExec -p raw rimages.tbl ../pleiades.hdr projected stats.tbl ;
  mImgtbl projected pimages.tbl ;
  mAdd -p projected pimages.tbl ../pleiades.hdr ${bands}.fits ;
  cd .. ;

  mJPEG -blue DSS2B/DSS2B.fits -1s 99.999% gaussian-log \
        -green DSS2R/DSS2R.fits -1s 99.999% gaussian-log \
        -red DSS2IR/DSS2IR.fits -1s 99.999% gaussian-log \
        -out DSS2_BRIR.jpg

Contents of pleiades.hdr

  BITPIX = -64
  NAXIS = 2
  NAXIS1 = 4801
  NAXIS2 = 4800
  CTYPE1 = 'RA---TAN'
  CRVAL1 = 56.500000
  CRVAL2 = 23.750000
  CRPIX1 = 2401.000000
  CRPIX2 = 2400.500000
  CDELT1 = -0.000625000
  CDELT2 = 0.000625000
  CROTA2 = 0.000000
  EQUINOX = 2000.0