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COS Reference Files

COS Reference File Tables

Reference files used by the COS calibration pipeline (CALCOS)) are updated on a regular basis. Current reference files files can be retrieved from the HST archive, or downloaded directly from the lref directory. If you choose to access the files via this ftp server, keep in mind that there is a known bug in trying to access files via ftp server using Safari. The recommended browser is Firefox.

If you would like to receive an e-mail every time a new COS reference file is delivered and the database is updated, you can subscribe to the cos_reffiles_upd mailing list. To subscribe to this list, send an e-mail to MajorDomo @ stsci.edu with the following in the body of the message:
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Reference File Type Extension Header Keyword Detector
Flat Field Files
Accounts for pixel-to-pixel variations. More...
flat FLATFILE Both
Geometric Distortion Correction Images
Corrects for the intrinsic nonlinearity (INL) of the FUV detector. More...
geo GEOFILE FUV
Bad Time Interval Table
Lists the start and end times of known bad time intervals. More...
badt BADTTAB FUV
Baseline Reference Frame Table
Used when applying the thermal distortion correction. More...
brf BRFTAB FUV
Burst Parameters Table
Provides the parameters needed for deciding when the count rate in some time interval in FUV time-tag data is too high to be regarded as normal. More...
burst BRSTTAB FUV
1-D Extraction Parameters Table
Gives the location of the spectrum to be extracted from a 2-D image. More...
1dx XTRACTAB Both
Bad Pixel Table
Gives the locations of rectangular regions that cover portions of the detector that are known to be less than optimal. More...
bpix BPIXTAB Both
Deadtime Reference Table
Used to obtain the true number of events received compared to the number of events counted by the detector electronics. More...
dead DEADTAB Both
Dispersion Coefficients Table
Gives a set of polynomial coefficients for computing wavelength from pixel number. More...
disp DISPTAB Both
Calibration Lamp Spectra Table
Used to determine the pixel offset of the observed data. More...
lamp LAMPTAB Both
Pulse Height Parameters Table
Lists the lower and upper thresholds for valid individual pulse heights in TIME-TAG mode as well as the minimum and maximum values for the location of the mean value of the pulse height distribution used in ACCUM mode. More...
pha PHATAB FUV
Photometric Sensitivity Reference Table
Provides the information needed to convert from corrected detector counts to flux units. More...
phot FLUXTAB Both
Spectroscopic WCS Parameters Table
The spectroscopic WCS parameters table gives values to be used for populating the world coordinate keywords. More...
SPWCS SPWCSTAB Both
Time Dependent Sensitivity Table
Gives information about the relative sensitivity as a function of time and wavelength. More...
tds TDSTAB Both
Wavecal Parameters Table
Gives information about the relative sensitivity as a function of time and wavelength. More...
wcp WCPTAB Both
High Voltage Reference Table
The high voltage reference table gives the times when the FUV high voltage was changed More...
hv HVTAB FUV
Walk Correction Reference Table
The walk corection reference table gives parameters for correcting the pixel coordinates XCORR and YCORR of FUV TIME-TAG data More...
walk WALKTAB FUV
Gain Sag Reference Table
The gain sag reference table gives the locations of rectangular regions for portions of the FUV detector that have very low pulse height amplitude (PHA). More...
gsag GSAGTAB FUV