A Second Look at Striping Stan Kidder 5 Oct 2012

Methodology VIIRS SDR radiances were examined on two dates, 9 April 2012 and 29 September 2012 Examined the middle 37% of the elements (which are not subject to bow-tie deletions) Examined 22 granules (1056 scans) on 9 April and 25 granules (1200 scans) on 29 September near CONUS and near 1330 local time For each band, the mean radiance for each scan line minus the overall mean radiance was divided by an estimate of noise for each band. This is called the Normalized Deviation. 2

Noise (Estimated from measured SNR or NEDT) 3

Range (max – min)of Normalized Deviations Band Change M M M M M M M M M M M I I I M M I M M I M

M6 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 5 Black = saturation?

M13 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 6 Range of data may mask striping in this image Odd- and even-line striping

M10 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 7

M3 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 8

M7 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 9

M1 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 10

M2 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 11

M8 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 12

M4 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 13

M5 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 14

M12 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 15 Odd- and even-line striping

I3 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 16

I1 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 17

I2 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 18

M15 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 19 Odd- and even-line striping

M16 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 20

I4 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 21 Odd- and even-line striping

M14 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 22

M11 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 23

I5 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 24 Odd- and even-line striping

M9 Band Change M M M M M M M M M M M I I I M M I M M I M Range of Normalized Deviations 25

Conclusions (1/2) Results are similar in April and September cases. The M6 striping is smaller in September than it was in April, but is still very large. Also, there appear to be saturation issues. Some channels seem to have odd- and even- line striping. Some of the differences between September and April may be caused by real scene effects. 26

Conclusions (2/2) Comparing with noise is interesting and useful, but whether or not one can see striping depends on the magnitude of striping in comparison with the range of data in a scene. It is difficult to see any evidence of striping in the M13 image, for example, even though statistically M13 has the second largest striping (compared to noise). 27

BACKUP SLIDES From previous study 28

I1  0.64  m Very small deviation from Block Mean Radiance No noticeable striping Highly Enhanced Image 29

M6 –  m Very Large Striping Unenhanced Image 30

M13 – 4.05  m Moderate deviations from Block Mean Radiance, but hard to find striping 31

M10 – 1.61  m Moderate deviations—some striping visible in unenhanced image 32