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12.1 FITS File Formats

The various files associated with each image represent the stages of NEWSIPS processing starting with the raw image (RI) file and ending with the merged extracted image (MX) file containing fluxes, wavelengths and data quality ($\nu$) flags. The Final Archive FITS files produced for low-dispersion images include the following:

RILO
The RI stored as a FITS primary array. If a partial read was used to obtain the image, an image extension is included containing the original unshifted RI (i.e., all corrections for registration errors are included in the primary array).
LILO
The linearized (i.e., photometrically corrected) image (LI) stored as a primary array with the associated array of $\nu$ flags stored in a FITS image extension.
VDLO
The vector displacements (VD) file contains the vector displacements, which map raw space into resampled space, and the cross-correlation coefficients (XC), which describe the mapping from raw space to the appropriate level of the raw space Intensity Transfer Function (ITF). The VD are stored as a three-dimensional (3-D) primary array, and the XC are stored in a FITS binary table extension.
SILO
The resampled image (SI) stored as a primary array with the associated $\nu$ flags in an image extension.
MXLO
The MX stored in a binary table extension, with each row containing the data extracted from one aperture.
If the RILO contains spectra collected through both the large and small aperture, the VDLO, SILO, and MXLO will contain data from both apertures. This is a slight change from the IUESIPS processing in which separate files were created for each aperture.
 
In the case of a high-dispersion spectrum the following files are generated:
RIHI
The RI (no partial-read image extensions are applicable).
LIHI
The LI and associated $\nu$ flags.
VDHI
The VD and XC data.
SIHI
The SI stored as a primary array, with wavelengths and predicted and found line positions stored in a binary table extension. The associated $\nu$ and cosmic ray flags are contained in two image extensions.
MXHI
The MX stored in a binary table extension with each row of the table representing data for one spectral order.

Some images may be processed as both high- and low-dispersion images and, consequently, will have both sets of files in the archive. In these cases, two copies of the RI file will appear in the archives, due to the dispersion-dependent keywords assigned during processing. All low- and high-dispersion Final Archive file formats are summarized in Tables 12.1 and 12.2. File sizes and formats summarized as ``various'' in these tables are explicitly described in the subsequent sections of this chapter.


 
 
Table 12.1:  Low-Dispersion File Formats
File ID Data Stored Size Format FITS Type
RILO Raw Image 768x768 8-bit primary array
  Original Raw Image$^\ast$ 768x768 8-bit image extension
LILO Linearized Image 768x768 I*2 primary array
  Linearized Flag Image 768x768 I*2 image extension
SILO Resampled Image 640x80 I*2 primary array
  Resampled Flag Image 640x80 I*2 image extension
VDLO Vector Displacements 768x768x2 R*4 primary array
  Cross-correlation Parameters various various binary table extension
MXLO Extracted Spectra various various binary table extension
 
$^\ast$ In the case of partial-reads only.


 
 
Table 12.2:  High-Dispersion File Formats
File ID Data Stored Size Format FITS Type
RIHI Raw Image 768x768 8-bit primary array
LIHI Linearized Image 768x768 I*2 primary array
  Linearized Flag Image 768x768 I*2 image extension
VDHI Vector Displacements 768x768x2 R*4 primary array
  Cross-correlation Parameters various various binary table extension
SIHI Resampled Image 768x768 I*2 primary array
  SIHI wavelengths and various various binary table extension
  predicted and found line positions      
  Resampled Flag Image 768x768 I*2 image extension
  SIHI Cosmic Ray Image 768x768 8-bit image extension
MXHI Extracted Spectra various various binary table extension


next up previous contents
Next: 12.2 FITS Header Format Up: 12 Final Archive Data Previous: 12 Final Archive Data
Karen Levay
12/4/1997