Cal Subsystem

Calibration Subsystem Performance

The Wide Field Camera 3 instrument has four tungsten lamps and one deuterium lamp that are used to obtain internal flat-field images (flats). These flats are used to aid in the monitoring of the performance of the UVIS and IR detectors and are used to look for pixel-to-pixel variations, filter performance and other effects. Any of the four tungsten lamps can be used with either the UVIS or the IR detector, but for routine on-orbit observations only lamp 3 is used with UVIS and lamp 2 is used for IR. The deuterium lamp is solely used with the UVIS detector. The lamps all reside in a separate calibration subsystem which has a significantly different f-ratio from the external beam.

This page contains all of the results from our recent analyses of UVIS detector tungsten and deuterium flat-field images. Tungsten lamp flat-fields were taken between May 2009 to March 2021, and deuterium lamp flat-fields were taken between August 2009 to May 2021. The relevant publications are linked at the end of the page.

Tungsten Lamp and Filter Performance Charts

Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity
Ratio of tungsten internal flat-field images to SMOV versus time. Chip 1 data is shown as a blue square while Chip 2 data is shown as a red circle

Image ratio for each year vs SMOV. The colorbars for all years range from 0.95 to unity

Deuterium Lamp and Filter Performance Charts

The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields, in units of counts per second, for all years since WFC3 installation. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 2.5% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields for all years since WFC3 installation. In order to get all of the features to stand out, each quadrant is divided by the its median. Therefore, the each image and the corresponding colorbar are unitless. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.
The top panel shows the count-rate evolution for internal deuterium lamp flat-fields. The bottom panel shows the count-rate evolution normalized to the SMOV reference flat-field. In both panels UVIS1 is plotted as black circles and UVIS2 is plotted as open red squares. A linear least squares regression was fit to the UVIS1 and UVIS2 data separately and their slopes with standard errors are given in the legends.

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using a single image scaling. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants (A,B,D,C from upper left clockwise to lower left).

Median combined deuterium lamp flat-field ratios normalized to SMOV for each year since WFC3 installation using an image scale of +/- 7% of the median for each ratio. For presentation purposes each image has a thin white line plotted at x = 2048 and y = 2051 to separate the detector quadrants.

Median combined deuterium lamp flat-fields for all years since WFC3 installation. In order to get all of the features to stand out, each quadrant is divided by the its median. Therefore, the each image and the corresponding colorbar are unitless. For presentation purposes, a thin white line has been added at x = 2048 and y = 2051 to delineate the detector quadrants.