PDS_VERSION_ID = PDS3
RECORD_TYPE = "STREAM"
OBJECT = TEXT
PUBLICATION_DATE = 2006-12-22
NOTE = "CALIB directory contents"
END_OBJECT = TEXT
CALIB Directory Contents
This file describes the contents of the calibration directory. The Deep
Impact calibration pipeline used the files in this directory to reduce raw
data. The files were the result of the analysis of ground-based, thermal-
vacuum and in-flight data for the instrument. For more information
about these files, the analysis, and the calibration pipeline, see the
'Deep Impact Instrument Calibration' paper included on the Deep Impact
documentation volume, DIDOC_0001.
The calibration data were provided as FITS image files or ASCII tables.
The following file naming convention was used:
| | | | | |
| | | | | Optional filter number, temperature, or
| | | | | place holder such as '0' or '999'
| | | | |
| | | | Instrument/Image mode (1 through 7) or a place
| | | | holder such as '0' to indicate all modes
| | | |
| | | File version (1, 2, etc.)
| | |
| | Date from which file is valid. This is not the date the file
| | was created. A value of '020601' indicates the file was
| | created from thermal-vacuum data. A value of '000101' was
| | used a place holder. It provides no useful information
| | but was required to keep the pipeline running.
| Instrument designation (e.g. HRIIR for HRII)
Directory for the type of calibration file (e.g. FLAT)
Here is an example of a complete file name, FLAT/HRIIR_050112_1_7_0.FIT:
- FLAT Flat field
- HRIIR HRII Instrument
- 050112 Effective date of 2005-07-01 (launch); this flat can be
applied to images acquired on 2005-01-12 UTC or later
- 1 Version 1 of the file file for the specified effective date
- 7 Instrument (image) mode 7
- 0 Placeholder (not a filter or temperature)
- .FIT FITS file
Calibration files are grouped into subdirectories by type:
This subdirectory contains one table of the absolute calibration
constants for each instrument (image) mode. The first column
specifies the wavelength for the reading. The second column
specifies the conversion factor for areas not under the
anti-saturation filter. The last column contains the conversion
factors for areas under the anti-saturation filter. Two identical
files, one with a place holder of '000' and another with '999'
were created for the pipeline to allow existing processes to correctly
This subdirectory contains a lookup table for the correcting for
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.
This subdirectory contains maps that identify bad pixels for each
instrument mode. These are master maps where a pixel is flagged bad
it was determined to be bad in each of the four in-flight science
calibrations. Bad pixels are set to a value of 1. Also, the
reference rows and columns around the edges of the array are set to 1.
Good pixels are set to 0.
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.
This subdirectory contains dark frames for specific IR exposures.
The exposure ID to which this dark frame can be applied is specified
in the file name. These darks were created by averaging the frames
within the specified exposure ID that were not on the target (i.e.,
This subdirectory contains the four lossy lookup tables used to
decompress raw data.
This subdirectory contains master dark frames for each instrument
This subdirectory contains flat fields for each instrument mode.
Flat fields were derived from the linearity of each pixel. Some
flats are dummies (all ones) as required by the calibration pipeline.
This subdirectory contains mode-specific maps of the four coefficients
used in a polynomial to linearize the raw data numbers. Mode 5 must
use the mode 1 file. Modes 6 and 7 must use the mode 4 file.
This subdirectory contains a dummy point-spread function used by the
calibration pipeline when one is not available. It is simply a
centered delta function to prevent any changes to the data.
This subdirectory contains temperature-dependent, pixel-by-pixel,
spectral registration maps for each instrument mode. 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.
This subdirectory contains two tables, based on different sources,
that provide the solar spectral irradiance at 1 AU for the given
This subdirectory contains tables that specify the amount of gain
from electronic cross talk that occurs between all possible
combinations of the two quadrants of the IR array. There is one
table for each instrument mode. The cross-talk is across IR quadrants
is negligible, thus the table values are set to zero the automated
calibration pipeline from changing data.
Name Last modified Size Description
Apache/2.2.15 (Scientific Linux) Server at pdssbn.astro.umd.edu Port 443
Parent Directory -
abscalir/ 18-Sep-2006 15:37 -
adclut/ 19-Sep-2006 13:01 -
badpix/ 14-Nov-2006 11:48 -
bias/ 18-Sep-2006 16:05 -
dark/ 14-Nov-2006 18:06 -
decomprs/ 18-Sep-2006 16:15 -
drkmodel/ 19-Jul-2007 15:55 -
flat/ 20-Nov-2006 16:54 -
lindn/ 18-Sep-2006 16:58 -
psf/ 18-Sep-2006 16:44 -
specmap/ 18-Sep-2006 17:06 -
sunspec/ 18-Sep-2006 16:56 -
xtalk/ 19-Jul-2007 15:59 -
calinfo.txt 02-Jul-2007 15:07 12K