PDS_VERSION_ID = PDS3 RECORD_TYPE = "STREAM" OBJECT = TEXT PUBLICATION_DATE = 2010-09-10 NOTE = "Description of the contents of the CALIB/ directory" END_OBJECT = TEXT END CALIB Directory Contents This file describes the contents of the calibration directory. The EPOXI calibration pipeline uses the files in this directory to calibrate raw data from the EPOXI mission; many of the files are duplicates of those for Deep Impact. The files are derived from analysis of pre-launch thermal-vacuum data as well as from in-flight calibrations performed during the Deep Impact and EPOXI missions. For more information about these files, the analyses, and the calibration pipeline, see the Deep Impact instrument calibration paper included on the Deep Impact and EPOXI documentation data set, DI-C-HRII/HRIV/MRI/ITS-6-DOC-SET-V3.0. The calibration data are provided as FITS image files or ASCII tables. The following file naming convention is used: CCCCC/IIIIII_YYMMDD_V_M_FFF.{FIT,TAB} | | | | | | | | | | | Optional filter number (1 through 9), temperature, | | | | | or place holder value such as '999' | | | | | | | | | Instrument image mode (1 through 9) or a place | | | | holder value of '0' to indicate all modes | | | | | | | File version number (1, 2, etc.) for the given | | | effective date | | | | | Date from which file is effective. It is not the file | | creation date. A value of '020601' indicates the file was | | created from pre-launch thermal-vacuum data. The value | | '000101' is used as a place holder. It provides no useful | | information but is required to keep the pipeline running. | | | Instrument designation (e.g. HRIVIS for HRIV) | Directory for the type of calibration file (e.g. FLAT for flat fields) Here is an example of a complete file name, FLAT/HRIVIS_050701_3_1_9.FIT: - FLAT Flat field - HRIVIS HRIV Instrument - 050701 Effective date of 2005-07-01; this flat can be applied to data acquired on 2005-07-01 UTC or later - 3 Version 3 of the file for the specified effective date - 1 Instrument image mode 1 - 9 Filter 9 - .FIT FITS file Calibration files are grouped into subdirectories by type: ABSCALVS -------- This subdirectory contains ASCII text tables of the absolute calibration constants for all instrument (image) modes. The first column in a table specifies the constant for converting raw data numbers to units of radiance, W/(m**2 sr um). The second column specifies the constant for converting from units of radiance to units of reflectance (i.e., I-over-F or the observed radiance over the input solar radiance, unitless). ADCLUT ------ This subdirectory contains a look up table for the correction of uneven bit weighting caused by the analog-to-digital conversion. The single table applies to all instrument modes. As of this archive, the corrections had not been derived. Therefore, the input pixel values are the same as the output values to prevent the automated calibration pipeline from changing the data. BADPIX ------ This subdirectory contains maps that identify bad pixels for all instrument modes. Bad pixels are set to a value of 1. Good pixels are set to 0. Pixels in the serial and parallel overclock columns and rows are flagged as good (0). For each image mode, there is one row of warm pixels near the top and bottom edge. These rows are flagged as bad (1). BIAS ---- This subdirectory contains bias correction maps for all instrument modes. DECOMPRS -------- This subdirectory contains the four 8-bit lookup tables used to decompress raw data numbers. DRKMODEL -------- This subdirectory contains master dark frames for all instrument modes. FILTERS ------- This subdirectory contains one transmission profile table for each HRIV filter. FLAT ---- This subdirectory contains flat fields for every combination of instrument mode and filter. PSF --- This subdirectory contains maps of the two-dimensional point-spread function (PSF) for all filters. The PSF can be used to deconvolve an out-of-focus HRIV image. XTALK ----- This subdirectory contains FITS files that specify the amount of gain from electronic cross talk that occurs between all possible combinations of the four quadrants of the CCD. There is one file for each instrument mode.