Filename                               Reason     Bkg         V      RCAM      TCAM   Sigma
20210929.181057.ucomp.637.l1.p3.fts         0    23.6      4.14       0.3       0.2    1.06
20210929.184014.ucomp.637.l1.p3.fts         0    23.3      4.21       0.3       0.2    1.11
20210929.214527.ucomp.637.l1.p3.fts         0    25.2      3.79       0.3       0.2    0.75
20210929.221446.ucomp.637.l1.p3.fts         0    30.4      3.90       0.2       0.1    0.88

GBU bitmask codes
Code    Description
    1   spar guide control loop is below threshold (0.99)
    2   spar guider intensity below threshold (0.9 * 6.551 * exp(-0.05 * secz))
    4   median background is above threshold (45.0)
    8   median background is below threshold (5.0)
   16   spurious Stokes V signal is above threshold (8.0)
   32   the chi-squared of the occulter fit is above threshold (1000.0)
   64   the difference of the image with the median is above threshold (1.8)

* indicates that the threshold values changed on the day