------------------ CISSCAL 4.0 README ------------------ CISSCAL is the Cassini ISS image calibration software package. For more information, including detailed setup instructions, please see Section 4.4 of the ISS Data User's Guide, available in the document/ directory of the ISS Calibration Volume (COISS_0011 version 4.2) or at the following URL: https://pds-imaging.jpl.nasa.gov/documentation/iss_data_user_guide_180916.pdf Additionally, see make_polar_image_readme.txt for information regarding polarization calibration using the standalone code make_polar_image.pro. Note that when downloaded from the PDS, the CISSCAL software will be found in the extras/cisscal/ directory, and the calibration support files will be found in the calib/ directory. CISSCAL is written in Interactive Data Language (IDL), and must be run on a computer on which IDL has been installed. As of this writing, CISSCAL has been tested for compatibility with IDL versions 5.5 through 8.2. In addition, the following system variables must be set (typically in user's .cshrc file or equivalent) for CISSCAL to work properly: - CisscalDir, directory containing CISSCAL code, e.g. setenv CisscalDir /home/username/cisscal - CalibrationBaseDir, directory containing calibration support files, e.g. setenv CalibrationBaseDir /home/username/calib - ImageBaseDir, default image directory, e.g. setenv ImageBaseDir /home/username/images The default calibration options can be set by the user by editing the text file cisscal_default_options.txt, located in the CisscalDir defined above. CISSCAL was developed in stages, beginning in August 1998, under the auspices of the Cassini Imaging Central Laboratory for Operations (CICLOPS) directed by Dr. Carolyn Porco, ISS Team Leader. The theoretical basis and pipeline design for Cassini image calibration was developed by ISS team member Dr. Robert West of JPL. The systems design for the CISSCAL software, and its original implementation and development, was the work of Dr. Kevin Beurle at Queen Mary, University of London from August 1998 through March 2002. Beginning in April 2002, major design and algorithmic modifications, software additions, debugging and maintenance have been performed by Ben Knowles of CICLOPS/Space Science Institute, Boulder, CO under the direct supervision of West. Significant contributions (algorithms, software, evaluation and validation, etc.) have been made by West, Vance Haemmerle of JPL (while at CICLOPS), Daren Wilson of CICLOPS, and other members of the Cassini ISS Team. Direct all questions to Ben Knowles at Space Science Institute, Boulder, CO (ben.cisscal@gmail.com). -Ben Knowles, 7/7/2019 Version history: ---------------- New in version 4.0: . Improved logic in option file reader and cisscal_cl.pro . Changed formatting of bitweight files to ease parsing . Added logic to handle bias/2-hz noise removal for TABLE images of various gain states . Improved CISSCAL_Log formatting . Updates to polarized filter algorithm in make_polar_image.pro (see make_polar_image_readme.txt). New in version 3.9.1: . Fixed non-working "hotpix" keyword in command line code . Removed obsolete text from batch GUI New in version 3.9: . Significant update to absolute correction for NAC and WAC: . New correction factors . Updated quantum efficiency correction . Added sensitivity vs. time correction . Incorporated solid angle/effective area values with more traceable provenance . Removed Jupiter absolute calibration option (no longer needed) . Updated command line code to match changes to calibration options file . Fixed mkdir path bug in subtractdark (now compatible with 'space' character) . Incorporated hot pixel data since 2012 . Added hot pixel on/off toggle to subtractdark and associated GUI changes . Added saturated/missing pixel value dialog to GUI . Replaced binary options file with text-based version (e.g. cisscal_default_options.txt) . Incorporated changes for possible future GDL compatibility (CassLabels class attributes) . Fixed negative values in BIAS_STRIP_MEAN bug . Improved plot range in "plot overclocks" code . Converted mottle file from TIFF to VICAR format . Cleaned up and improved batch mode text entry and dialogs . Extended Jupiter and Saturn solar distance files through end of mission . Added functionality for and improved handling of shutter-inhibited images . General code and comment cleanup New in version 3.8: . Fixed bugs in command-line mode. . Fixed negative array index bug in label reading code. . Fixed polarized filter bug in dust ring code. . Added NAC dust ring corrections derived from Titan atmosphere images. . Added correction to preexisting bright ring for images with anti-blooming mode = OFF. . Changed flatfield algorithm to ignore NaN pixels in slope files. . Added WAC filters to Jupiter correction. . Switched default CL1/CL2 slope files from gain 3 to gain 2. New in version 3.7: . Improved and cleaned up log output throughout code. . Modified VICAR label behavior, added "show/hide label" menu option. . Various GUI enhancements/adjustments to make suitable for smaller screen resolutions. . Added Jupiter correction factors and corresponding GUI option. . Added saturated and missing pixel output values to options file. . Improved handling of polarized images. . Removed old IDL code version tags. . Fixed various display and GUI bugs. . Moved plot overclocks button to Tools menu. . Fixed error handling for invalid image files. . Added bias subtraction and de-LUT to image mean mask preview. . IDL 8 compatibility changes. . New dark label format; old dark repositories will be ignored. . Consolidated GUI and command line option file reader (cisscal_readoptfile). . Simplified GUI and improved logic for bias/two hz noise removal. . Added binary header to output VICAR files, cleaned up VICAR write code. . Updated shutter offset values. . Re-designed output VICAR label format. . Improved bias subtraction and 2 Hz noise removal: better filtering, better handling of missing lines and slow-readout images. . Removed horizontal ringing artifacts and residual hot pixel streaks from dark current parameter files, and corrected saturated pixels. . Added hot pixel files and updated dark subtraction algorithm accordingly. . Added intermediate options for DN-to-flux conversion. . Updated format of system transmission files, included transmission for both parallel and perpendicular orientations of polarized filters. . Added make_polar_image.pro for processing polarized images; modified absolute flux correction for use with new version of polarizer code. New in version 3.6 (changes since version 3.3): . Improved dark simulation code to increase speed. . Modifications to handling of summed and lossy-compressed images by 2 hz removal routine. . Incorporated latest NAC and WAC absolute correction factors. . Combined, where possible, system transmission files (located in support/efficiency/systrans/) with "blocking" filter transmission from ground calibration. . Added cisscal_cl, the CISSCAL command-line mode, enabling use of CISSCAL without the GUI. . Added compatibility for several operating systems, including Mac. . Removed 2-parameter dark current model (now defunct). . Added default options file, cisscal_default_options.txt, allowing user to specify defaults for all calibration parameters. . Updates to linetime.pro (readout time calculation). . Various bug fixes and clean-up of GUI toggle and window behavior. . Changed histogram code to allow large DNs. . Implemented a slightly wider low-pass filter for 2-Hz removal to deal better with cosmic rays in overclocked pixels. . Disabled 2-Hz noise removal for summed images. . Updated user manual. . Data file clean-up, reformatting. . Extended Sun-Saturn distance calculator to be useful for images taken after 2009. . Added output filename suffix to calibration options file. . Added new central/effective wavelength files. . Added omega0.tab (in place of effic_db*). . Fixed flight software version bug in debias code. . Cleaned up rebinning behavior in flatfield code.