The PixToPixSens file describes the
spatially high frequency throughput and sensitivity non-uniformities.
In addition PixToPixSens describes the illumination pattern of the
internal calibration lamps seen by the detector.
The high frequency sensitivity variations are introduced by
the detector. Non-uniformities in the filter
transmissions won't show up in small scale structures,
as the filter wheel elements are out of focus.
The PixToPixSens file describes the inverse detector sensitivity normalized to the average sensitivity. Values less than one indicate pixels with a sensitivity higher than the average and values greater than one indicate pixels with a lower sensitivity than the average.
PixToPixSens consists of two image extension. The Image extension has a size of 2048x2048 pixel and is at full detector resolution. The extension name is PIXTOPIXSENS. The keyword CFRR specifies the average count rate (units: count/CCD frame) in the flatfield exposures used to generate the image extension.
The image extension LEDTEMPLATE holds the description of the LED illumination pattern. The illumination pattern is described as the inverse illumination level by a full resolution map (2048x2048 subpixel). Values less than one indicate pixels with a stronger illumination by the LEDs (higher than the average) and values greater than one indicate pixels with a lower illumination than the average.
The image extension in the pixtopixsens CCF component has the following
structure PIXTOPIXSENS.
Image extension: PIXTOPIXSENS
| keyword name | keyword | keyword | keyword | comment |
| type | unit | value | ||
| NAXIS | Integer | n.a. | 2 | number of data axes |
| NAXIS1 | Integer | n.a. | 2048 | length of data axis 1 |
| NAXIS2 | Integer | n.a. | 2048 | length of data axis 2 |
| CFRR | Real | cts/fullframe/sec | varies | average CFRR |
| AVERAGE | Real | n.a. | varies | average sensitivity of good pixels |
| DAVERAGE | Real | n.a. | varies | standard deviation on AVERAGE |
| PIXERR | Real | percent | varies | average standard deviation on |
| single pixel value |
The second image binary extension in the pixtopixsens CCF component
is LEDTEMPLATE with the structure as follows.
Image extension: LEDTEMPLATE
| keyword name | keyword | keyword | keyword | comment |
| type | unit | value | ||
| NAXIS | Integer | n.a. | 2 | number of data axes |
| NAXIS1 | Integer | n.a. | 2048 | length of data axis 1 |
| NAXIS2 | Integer | n.a. | 2048 | length of data axis 2 |
| AVERAGE | Real | n.a. | varies | avg. correction for nonflat illumination |
| DAVERAGE | Real | n.a. | varies | standard deviation on AVERAGE |
| PIXERR | Real | percent | varies | average single pixel deviation |