Measuring Pixel Correlations on SLAC Data Emily Phillips Longley - PowerPoint PPT Presentation

Measuring Pixel Correlations on SLAC Data Emily Phillips Longley

Current implementation ● Using the CrossCorrelate function of the BfTask class ● Takes in masked objects ● Outputs the correlations ○ lsst.afw.image.MaskedImageF ● Not using the Butler

Image Pre-Processing using Eotest tools ● Median bias frame subtraction ● Overscan correction using Bela’s function, doing a row-by-row subtraction ● Masking objects by passing ○ Mask_files = (mask_dark_pixels.fits,mask_bright_pixels.fits) ○ when creating the masked_ccd object

Correlation Functions ● Doing a per-amplifier analysis. Normalized correlations Normalized correlations Amp 2 Amp 1 y (pixels) Y (pixels) x (pixels) x (pixels) Normalized Correlation Normalized Correlation Function Function � 4

Currently not implementing ● Image processing ○ No crosstalk correction ○ No linearity correction ● Not generating the kernel ● Not performing a correction on images

Eventually Wish to Implement ● Generating the kernel and performing the correction on images! ● Specifically interested in: ○ Applying the correction to lab spots data ● Currently there is a Spots Analysis Task being developed to be a regular eotest test ○ https://github.com/lsst-camera-dh/eotest/tree/LSSTTD-1297 ○ Added a portion to calculate the widths of the spots using the Fe55 function ○ Taking single spots data at various flux levels to measure brighter fatter