VII. WISE Data Processing

3. 3-Band Cryo Data Processing

h. Quality Assurance (QA)

The objective of science data quality assurance on the 3-band cryo data was identical to that described for the WISE All-Sky Data Release. The methodology was also identical. The thresholds used to assess data quality were, however, tweaked slightly in recognition of the fact that the overall character of the W3 data changed relative to the cryo data and that there were no W4 data to assess.

For ScanFrame data, all W4-related checks were dropped. Thresholds were modified for the background and noise quality factor (qn) in the W3 band, specifically the thresholds related to subfactors qn_bkg (assessing excessively noisy or high-background data) and qn_bdp (assessing the number of bad pixels):

qn_bkg: If the following check failed, qn_bkg=0.0. Otherwise, qn_bkg=1.0. (Here, intMedian was the median value of all exposed [non-reference] pixels on the array.)
W1: intMedian < 4000
W2: intMedian < 3000
W3: intMedian < 30000 (this had been set to 10000 for the four-band cryo data)
W4: intMedian < 8000

qn_bdp: If the total number of masked pixels labeled as bad exceeded 150,000 in W3 or 100,000 in either W1 or W2, qn_bdp=0.0. Otherwise, qn_bdp=1.0. (Previously, the threshold was 100,000 in all three bands.)

Thresholds for the other qn subfactor, qn_sgm, was left unchanged as were the threshold values for factors qc and qi. For more information, please see the Frame-level metrics in the WISE All-Sky Explanatory Supplement.

For Multiframe data all thresholding for the W3 band was dropped relative to the thresholding used for the All-Sky Release Multiframe metrics. (Note that thresholds were not applied to W4 data in the four-band cryo data either.)

Last update: 2012 May 10