First are simple plots of J band, H band, and K band PSF mag normalization vs. scan number, with error bars indicating the rms of the median normalization value. Note that the unusual PSF mag normalization values derived for scans 8 and 9 on 970619 occur in the calibration set for which the image aspect ratios were normal (near unity); thus these values are not caused by image smearing. Instead, they are caused by large values of the shape parameter, meaning poor seeing. This is evident when comparing the plots of J band, H band, and K band PSF mag normalization vs. the image aspect ratio, and J band, H band, and K band PSF mag normalization vs. the mean shape parameter for each scan. Larger rms error bars on the PSF mag normalization values are a result of not only increased scatter in the values used in the median normalization determination, but also fewer numbers of values used in the determination, since only "good" stellar sources which pass a PSF goodness-of-fit test are used, and naturally, few smeared sources can pass this test.
To see how the shape parameter correlates with the image aspect ratio,
look at these plots of J
band, H
band, and K
band mean shape parameter vs. image aspect ratio.
