6.5 PHOTOM Output

The low-/high-dispersion LI FITS files (LILO/LIHI) are the main output data product produced during the PHOTOM stage of image processing. This file contains the LI and associated $\nu$ flag (LF) data. For both low and high dispersion, the LI and LF arrays are full 768 × 768 images. The LI contains FN values in RI space for the data which have been PHOTOMed. Since the LI was created by overwriting a copy of the RI, the remainder of the data in the LI frame outside the PHOTOM region are the raw data scaled down by a factor of 32. The LF contains the PHOTOM $\nu$ flag error conditions which have been combined with the conditions determined during the raw image screening portion of image processing. The intensity data (LI) are output as the FITS primary array, and the associated $\nu$ flags (LF) are output as the corresponding FITS image extension to the LILO/LIHI.

The PHOTOM module writes the following information to the HISTORY portion of the image label:

• ITF used by PHOTOM (camera and ITF acquisition epoch),
• mean THDA of ITF,
• ITF UVC voltage, UV flood wavelength, ITF SEC voltage, and
• ITF characteristics and construction date.