PDS_VERSION_ID              = PDS3
RECORD_TYPE                 = STREAM
OBJECT                      = TEXT
  PUBLICATION_DATE          = 2009-03-17
  NOTE                      = "Description of the CALIB directory
                               contents for the CASSINI ISS EDR 
                               archive."
END_OBJECT                  = TEXT
END

                         CALIB Directory Contents

The CALIB directory contains Cassini ISS calibration data files derived from
ground and in-flight calibration analyses. Some of these files may not 
explicitly conform to PDS format.

The directory and filenaming structure of the CALIB directory is set up to
be fully compatible with the CISSCAL software package contained in the
EXTRAS directory on this volume. In order to ensure that filename cases
remain the same, regardless of the DVD filesystem being used, the entire
contents of the CALIB subdirectories have also been provided in a g-zipped
TAR archive, calib.tar.gz. 

For a brief tutorial on Cassini image calibration, see section 5 of the 
CISSCAL manual which can be found in the document subdirectory on the 
Calbration archive volume.

calib.tar.gz - Entire contents of the below subdirectories contained in a 
               single g-zipped TAR archive.

antibloom/   - Files containing masks of the anti-blooming mode pixel pairs 
               in the NAC and WAC, as seen in ground calibration data.

bitweight/   - Files containing bitweight corrections as a function of camera,
               optics temperature (-10, +5, +25 degrees C) and gain state, as 
               derived during ground calibration.

correction/  - Files containing normalized wavelength-dependent correction 
               function to be applied to the quantum efficiencies of the NAC 
               and WAC during absolute calibration, as well as files 
               containing filter-specific correction factors to be applied to 
               each filter combination individually. 

darkcurrent/ - Image files containing the dark parameters for the 
               interpolation dark model used in CISSCAL.

distortion/  - Files containning a lists of NAC and WAC focal lengths for use
               in correcting geometric distortion.

dustring/    - This directory contains VICAR-image files used to correct for 
               dustrings that are not found in the slope files created during 
               ground calibration.

efficiency/  - This directory contains various files necessary for calculating
               the transmission of the ISS cameras as a function of 
               wavelength.

               efficiency/systrans - This subdirectory contains the 
               non-wavelength-integrated system transmission values 
               (QE*optics*filter1*filter2) for each filter combination.

lut/         - This directory contains the inverse-lookup table used to 
               convert table-encoded Cassini ISS images from an 8-bit range 
               back 12-bit.

offset/      - The offset directory contains shutter offset information for 
               each camera as a function of temperature.

slope/       - The slope directory contains the VICAR-format "slope files" 
               derived during ground calibration, and used by the calibration 
               software as flatfields. Database files are also included which 
               specify the recommended slope files to use for each filter 
               combination at a given optics temperature.