scale = 0 - 0.06
counts = (2.46 +/- 1.27)X10-2
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This is the routine 160 µm dark and noise measurement. There were two such measurements in Campaign O. The first uses a stim flash DAC of 0x4D, while the second uses a stim flash DAC of 0x37. The switch between DAC settings was done at the end of MIPS-180 by accident. The 160 µm array was run at 10/15/15/15 mV for modules 1/2/3/4 in this campaign.
For the first dark measurment, the average dark current was (2.46 +/- 1.27)X10-2 MIPS160 units. The average noise was 1199.9 +/- 656.0 e for the average of two 5 MIPS second DCEs. This translates to a noise of 32.2 +/- 17.6 DN/sec on the slope measurement (286.3 +/- 187.1 DN/sec).
For the second dark measurment, the radhits were intense enough to cause saturation for most of the array. Thus, no dark or noise measurement is possible for the 2nd set.
For comparison to other campaign dark/read noise measurements as well as ground test data, see the meta task 2005.
The dark data were reduced using the DAT version 2-32. Sensitive cosmic ray detection (mips_sloper comandline switch -q) was used and the electronic nonlinearity correction was not applied. The read niose input into mips_sloper was 100 electrons. The dark datasets were run through mips_caler. Finally, the dark image for d3 were created using mips_enhancer. The mips_enhancer was run with the commandline options "-OW -OD -D". The noise was measured from the noise datasets using the get_rdnoise.pro program.
The d3 dark images were examined. As has already been reported elsewhere, this array has a bad readout (1x5 region). The measured dark is give below.
| 160 Dark (d3) |
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scale = 0 - 0.06 counts = (2.46 +/- 1.27)X10-2 |
The noise were determined for the d3 noise datasets. Many of the pixels on have many cosmic rays. Thus, we have measured the noise both with the new empirical method as well as the standard method. Our standard method of measuring noise is to determine the standard deviation of all the slopes of a pixel without detected cosmic rays. The empirical method is to do an iterative sigma rejection of deviant slopes. The results of the two methods are shown below. Given the middle reset each DCE, the noise measurement is for the average of two 5 MIPS second ramps. Thus, the effective exposure of the measurements is two times 5 MIPS seconds, not 10 MIPS seconds. This point is made as the noise we are measuring is 1/f noise and the specifics of how the data are taken are important. We have also quoted the noise on the good engineering pixels. These "pixelless" pixels give a good measure of the noise introduced by the electronics themselves. In the images below, the middle (non-existant) row has been removed.
The noise measurement given here is the noise in excess of that expected from photon statistics.
| Empirical Sigma Rejection (cut at 3*sigma) |
All DCEs with CR detected rejected plus empirical Sigma Rejection (cut at 3*sigma) |
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| Flight Data (mips_IER_7534592_d3_rn_A160_P24_10s) | |||
 scale = 0 - 4000 e counts = 2032.5 +/- 1328.4 e/s noise = 1199.9 +/- 656.0 e DCEs used = 48.85 per pixel 34 pixels Eng. Pixels noise = 57.6 +/- 9.6 e 12 pixels |
 scale = 0 - 4000 e counts = 2033.7 +/- 1343.7 e/s noise = 887.1 +/- 525.6 e DCEs used = 25.47 per pixel 34 pixels Eng. Pixels noise = 54.4 +/- 5.0 e 11 pixels |
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The dark measured in the d3 position should be used for standard calibrations.
The dark calibration image to be used for standard calibrations of campaign O data has been delivered and distributed with the suite of CamO cal files.
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