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Next: caldx: calibrate dx zero-point

caldark: Calibrate for shutter closed effects

For information about dark images and other issues relevant for the correction for dark current, see the appropriate inside information.

"caldark" can collect and analyze short and long exposure dark images. to be able to correct for time dependent and time independent shutter closed effects.

Usage:

caldark [options] [make|makeshort|makelong|makezing]

Without any argument, the "caldark" program will

analyze earlier collected short dark images (sdark.kcd, older versions created images "sdark0.kcd" through "sdark9.kcd"). This will result in a file "sdark.kcd_frozen" and a file "badpixel.sdark"
analyze earlier collected long dark images (ldark.kcd, older versions created images "dark1.kcd" through "dark9.kcd"). This will result in a file "dark.kcd_frozen" and a file "badpixel.dark"

With the argument "makeshort" it will make a file "sdark.kcd" (takes only a few minutes); with the argument "makelong" it will collect "ldark.kcd" first (3.5 hours); The argument "make" can be used as an abbreviation of the combination "makeshort makelong". With the argument "makezing", the program will create a 10-fold image with 600 second dark exposures. This is the standard image to check the behaviour of zingers on the detector.

Possible options are:

numimg=#: Specifies the number of times the short dark and long dark images should be collected. Must be 10 or larger.
shortsweep: Specifies that the short dark image should also correct for a horizontal wave.

The resulting "dark.kcd_frozen", "sdark.kcd_frozen", "badpixel.dark" and "badpixel.sdark" should be copied to the calibration directory. If a file "badpixel.ndark" exists there, it should be removed.

Example output

devel[185]dark%% caldark
Loading: ['sdark00.kcd', 'sdark01.kcd', 'sdark02.kcd', 'sdark03.kcd', 'sdark04.kcd', 'sdark05.kcd', 'sdark06.kcd', 'sdark07.kcd', '
sdark08.kcd', 'sdark09.kcd']
Frame 1, Locating minimum/maximum
.
.
.
Frame 20, Locating minimum/maximum
Using detector gain of 1.60
Frame 1, Averaging, 2 pixels rejected
.
.
.
Frame 20, Averaging, 3 pixels rejected
Frame 1, Determining Stdev, 2 pixels rejected
.
.
.
Frame 20, Determining Stdev, 4 pixels rejected
Frame 1, Averaging, 182 pixels rejected
.
.
.
Frame 20, Averaging, 144 pixels rejected
2753 pixels hit by 1 or more zinger
0 pixels hit by 2 or more zingers
0 pixels hit by 3 or more zingers
median stdev in sum = 7.53
2 pixels with stdev>3*median
Frame 1, Tabulating strange pixels
.
.
.
Frame 20, Tabulating strange pixels
2753 pixels hit by 1 or more zinger
1 pixels hit by 2 or more zingers
0 pixels hit by 3 or more zingers
median stdev in sum = 7.53
1 pixels with stdev>3*median
Sending AVERAGE image
Scaling down by number of readouts (1)
Average of shortdark image = 2.06 ADC units
Raw standarddeviation in shortdark image = 0.92 ADC units
2nd raw standarddeviation in shortdark image = 0.57 ADC units
Final standarddeviation in shortdark image = 0.54 ADC units
Number of significantly low pixels (ADC<0.4) = 617
Number of significantly nonempty pixels (ADC>3.7) = 1241
Scaling image by factor 10.00
Adding 28.1 to all values
Frozen sdark file saved.
Sending STDEV image
Median variance = 2.83
Number of pixels with variance>45.34 = 0
Loading: ['dark1.kcd', 'dark2.kcd', 'dark3.kcd', 'dark4.kcd', 'dark5.kcd', 'dark6.kcd', 'dark7.kcd', 'dark8.kcd', 'dark9.kcd']
Loading local short dark image : ./sdark.kcd_frozen
Frame 1, Locating minimum/maximum
.
.
.
Frame 18, Locating minimum/maximum
Using detector gain of 1.60
Frame 1, Averaging, 809 pixels rejected
.
.
.
Frame 18, Averaging, 778 pixels rejected
Frame 1, Determining Stdev, 885 pixels rejected
.
.
.
Frame 18, Determining Stdev, 855 pixels rejected
Frame 1, Averaging, 1778 pixels rejected
.
.
.
Frame 18, Averaging, 1852 pixels rejected
32057 pixels hit by 1 or more zinger
980 pixels hit by 2 or more zingers
26 pixels hit by 3 or more zingers
median stdev in sum = 8.01
258 pixels with stdev>3*median
Frame 1, Tabulating strange pixels
.
.
.
Frame 18, Tabulating strange pixels
32098 pixels hit by 1 or more zinger
1055 pixels hit by 2 or more zingers
49 pixels hit by 3 or more zingers
median stdev in sum = 8.01
177 pixels with stdev>3*median
Sending AVERAGE image
Scaling down by integration time (1200.1)
Average of longdark image = 2.33 ADC units
Raw standarddeviation in longdark image = 9.80 ADC units
2nd raw standarddeviation in longdark image = 4.38 ADC units
Final standarddeviation in longdark image = 3.18 ADC units
Number of significantly low pixels (ADC<-7.2) = 615
Number of significantly nonempty pixels (ADC>11.9) = 5467
Writing image in original scale
Adding 98.0 to all values
Frozen dark file saved.
Sending STDEV image
Median variance = 3.55
Number of pixels with variance>56.81 = 69

Now copy the dark.kcd_frozen, sdark.kcd_frozen,
badpixel.dark and badpixel.sdark files to the calibration
directory. (This normally is /usr/local/calibration/<detid>/)
If an older 'badpixel.darkn' file exists there, remove it.

caldark 381.64s user 96.59s system 87% cpu 9:04.19 total

Previous: makedetalign: measure detector alignment
Next: caldx: calibrate dx zero-point