PDS_VERSION_ID = PDS3 RECORD_TYPE = "STREAM" OBJECT = TEXT PUBLICATION_DATE = 2014-01-31 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 Deep Impact/EPOXI calibration pipeline uses the files in this directory to calibrate raw data from the EPOXI mission; some files are duplicates of those used for Deep Impact mission. Calibration files were derived from analysis of pre-launch thermal-vacuum data or from in-flight calibrations performed during both missions. For more information about these files, the analysis, and the calibration pipeline, see the EPOXI Calibration Pipeline Summary document in this dataset and 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-V4.0. The calibration data are provided as FITS image files or ASCII tables. The following file naming convention is used: CCCCC/IIIIII_YYMMDD_V_M_FFFFFFFFFF.{FIT,TAB} | | | | | | | | | | | Optional filter number, temperature, exposure ID | | | | | and frame number (such as 9000042000), or place | | | | | holder (such as '0' or '999') | | | | | | | | | Instrument image mode (1 through 7) or a place | | | | holder value of '0' to indicate all modes | | | | | | | File version number (1, 2, etc.) for the given | | | effective date | | | | | Effective date for using the file (not the file creation | | date). Multiple calibration files may exist for the same | | application, reflecting changes in the instrument as a | | function of time, and this field defines the start of the | | observation window where the file is used in the reduction | | process. It is used for all subsequent observation dates | | until a file with a later effective date supersedes its use. | | The value '000101' is used as a place holder, in which case, | | the file provides no useful information but is required to | | keep the pipeline running. | | | Instrument designation (e.g. HRIIR for HRII) | Directory for the type of calibration file (e.g. BADPIX) Here is an example of a complete file name, BADPIX/HRIIR_100928_1_4_999.FIT: - BADPIX Bad pixel map - HRIIR HRII Instrument - 100928 Effective date of 2010-09-28; this bad pixel map applies to data acquired on or after 2010-09-28 UTC or - 1 Version 1 of the file file for the specified effective date - 4 Instrument image mode 4 - 999 Placeholder (not temperature or exposure ID dependent) - .FIT FITS file Calibration files are grouped into subdirectories by type: ABSCALIR -------- This subdirectory contains mode-dependent files for converting raw data numbers (DN/s) to units of radiance W/(m**2 sr um). For each wavelength a conversion factor for areas not under the anti-saturation filter and another one for areas under the anti-saturation filter are provided. Two identical files for each mode, one with a place holder of '000' and another with '999' were created for the pipeline to allow existing processes to correctly execute. ADCLUT ------ This subdirectory contains a lookup 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 mode-dependent maps that identify bad pixels. Bad pixels are set to a value of 1. Also, the non-image reference rows and columns around the edges of the array are set to 1. Good pixels are set to 0. BIAS ---- This subdirectory contains a dummy bias correction map for each instrument mode. All bias maps are set to zero to prevent the automated calibration pipeline from changing data. DECOMPRS -------- This subdirectory contains the four 8-bit lookup tables used to decompress raw data numbers. DRKMODEL -------- This subdirectory contains mode-dependent master models of the dark current. FLAT ---- This subdirectory contains the single, full-frame, unbinned, master flat field derived from lunar calibrations. The calibration pipeline uses this file to perform flat-field correction for all image modes, including binned, full-frame and sub-frame modes. LINDN ----- This subdirectory contains mode-dependent maps of the per-pixel coefficients used in a fourth-order polynomial to linearize the raw data numbers. PSF --- This subdirectory contains a default point-spread function used by the calibration pipeline. This file is a placeholder that simply provides a centered delta function to prevent the pipeline from making any changes to the data. The project does not plan to improve it. QE -- This subdirectory contains the quantum efficiency curve for the IR focal plane array. SPECMAP ------- This subdirectory contains mode-dependent, temperature-dependent, per-pixel, spectral registration maps. The first dimension provides the wavelength; the second provides the spectral resolution (delta wavelength). The temperature string in the file names refers to the temperature of the IR spectrometer for which a map is applicable. SUNSPEC ------- This subdirectory contains two tables, based on different sources, that provide the solar spectral irradiance at 1 AU for the given wavelengths. XTALK ----- This subdirectory contains mode-dependent tables that that provide ratios (coefficients) to correct for the electronic cross talk (electronic ghosts) that occurs between the two possible combinations of the two quadrants of the IR array. The cross-talk between the IR quadrants is negligible; therefore all cross talk coefficient values in all are set to zero to keep the automated calibration pipeline from performing this correction. (That is, all tables irregardless of the version are identical and only contain zero values.)