7.7.2 High-Dispersion

The high-dispersion SI and VD FITS files (SIHI and VDHI, respectively) are the main output data products produced during the image resampling stage. The SIHI contains the geometrically resampled intensity values stored in a FITS primary array, the resampled $\nu$-flag image corresponding to the intensity data stored as a FITS image extension, the associated starting wavelength, wavelength increment, and predicted and found line positions for every order stored in a FITS binary table extension, and an array of pixels which have been flagged as cosmic rays by the high-dispersion COSMIC_RAY module stored as a FITS image extension. The VDHI contains the summation of all the geometric corrections implemented to perform the single image resampling and gives, for each pixel in LI space, the final x and y coordinate in SI space stored in a FITS primary array. As discussed in Chapter 5 , the raw cross correlation data are retained in a FITS binary table extension of the VDHI.

The following information is written to the HISTORY portion of the high-dispersion image label by the GEOM module:

• epoch of the spatial deviation (wiggle) file,
• de-splaying angle in radians, and
• predicted line center of a representative ``checkpoint'' echelle order (order 100 for SWP or order 90 for the LWP and LWR). The LWP processing HISTORY initially reported the line position for order 100. This was subsequently changed to order 90 after the start of the processing effort, as this order is in a region of higher sensitivity than order 100 for the LWP and LWR. This change only affects LWP and LWR high-dispersion images processed after July 28, 1997.