
metadata to extract:

typedef struct {
  char filename[64];
  char pathname[128];
  char instrument[32];
  char telescope[32];
  char objname[64];
  char extname[64];

  float ra, dec;
  float exptime;
  float airmass;

  float W0, W1, dW;
  int Nspec;				/* number of spectra associated with entry */

  char mode;			/* PHU, MEF, EXT */
  char state;			/* image state: raw, flx, etc */
  char flag;			/* image status flags */
  char junk[9];

  unsigned long int obstime;
  unsigned long int regtime;
} Spectrum;


FITS Keywords for metadata

case 1:
NAXIS  = 1
NAXIS1 = Nw

case 2:
NAXIS  = 2
NAXIS1 = Nw
NAXIS2 = 1

case 3:
NAXIS  = 2
NAXIS1 = 1
NAXIS2 = Nw

case 4:
NAXIS  = 2
NAXIS1 = Nw
NAXIS2 = n   (flux, dflux, etc)

case 5:
NAXIS  = 3
NAXIS1 = Nw
NAXIS2 = 1
NAXIS3 = n   (flux, dflux, etc)

0         1         2         3         4         5         6         7         8
012345678901234567890123456789012345678901234567890123456789012345678901234567890
/data/elixir2/datdir/megacam/03Am02/taurus/L1551/VLT/spectra/2002.04.01
