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January 24, 2011

About This Article


  • A bug which resulted in incorrect values in NUV x1dsum files has been fixed. In some cases there was a gap in the data quality flags (the DQ extension in the flt and counts files) between the near-edge flag and the out-of-bounds flag.  The data values were zero there, but because DQ was zero, the zero data values were included in the average in x1dsum.
  • The stim count rate was not being computed correctly.  This value is just printed for information pertaining to the deadtime correction.
  • A new command-line argument --find was added.  If specified, calcos will search for the target spectrum in the Y direction and use that location to extract the spectrum, rather than relying completely on the offset from the wavecal spectrum.
  • Options were added to the 1-D extraction to specify the location at which the spectrum should be extracted and/or the extraction height; these options are available via the x1dcorr task but not in calcos itself.
  • There were changes in the names and interpretation of some of the data quality flags.  In particular, one flag DQ_PHA_OUT_OF_BOUNDS (512) is now used to flag pulse height out of bounds, rather than having separate flags for low pulse height and high pulse height.
  • For most calibration steps for TIME-TAG data that use the exposure time, the value that will be used is the difference between the first and last events. This need not be the same as either keyword EXPTIME or the corrected value of EXPTIME.
  • New columns NET and BACKGROUND are now written to the lampflash table.
  • New segment-specific keywords are used.  Keyword SP_HGT has been changed to SP_HGT_A, SP_HGT_B, SP_HGT_C.  Keywords EXPTIMEA, EXPTIMEB, NBADEVTA, NBADEVTB
  • NEVENTSA, and NEVENTSB are now used for FUV.  NEVENTS will be set to NEVENTSA + NEVENTSB in an x1d table header.  New keywords SP_NOM_[abc] and SP_OFF_[abc] are now written when extracting a 1-D spectrum.  SP_NOM_[abc] is the nominal location (the expected value) of the spectrum where it crosses the middle of the flt or counts image, and SP_OFF_[abc] is the offset from
  • the nominal location to the location where the spectrum was actually found.
  • Segment-specific keywords will be updated in the corrtag files.
  • For TIME-TAG input, the headers of the ERR and DQ extensions of the flt and counts files had been created from the input EVENTS header, but this includes many superfluous keywords.  These headers are now created by explicitly writing just the relevant keywords.  In particular, segment- and stripe-specific keywords will no longer be present in the ERR and DQ extensions of flt and counts files.  These are not needed because they're in the SCI extensions, and previously they sometimes had default values in the ERR and DQ extensions.
  • For spectroscopic data, calcos now writes WCS keywords to the flt and counts images and to the corrtag table.  This is disabled, however, if the SPWCSTAB keyword is missing (which it will be unless explicitly added) or if its value is "N/A".  Information regarding updating of the spectroscopic WCS keywords will be written to the trailer file if the keywords were updated.
  • The values for keyword photfnu have been determined using pysynphot instead of calcphot.
  • The interpolation function now allows the independent variable to be constant over an interval, rather than requiring it to be strictly increasing or decreasing.
  • A command-line option --raw was added to create the csum file using raw pixel coordinates rather than corrected coordinates.
  • When writing the csum file, the high voltage keywords, subarray keywords, and exposure time keywords are no longer copied to the primary header. COUNTS and the binning keywords are now written to the extension header.
  • When the input is a corrtag file but with suffix "_rawtag", the input and output directories may now be the same.
  • If the FLUXTAB does not have a row matching the observing configuration, calcos was quietly setting the values in the FLUX column to zero.  Calcos now raises an exception if there is no matching row in the FLUXTAB.


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