https://pfspipe.ipmu.jp/jira This file is an XML representation of an issue en-us 8.3.4 803005 13-09-2019 https://pfspipe.ipmu.jp/jira/browse/PIPE2D-624 DRP 2-D Pipeline <p>Comparison between residuals between detector images in focus between two FRD values show noticeable jumps between the third and fourth row, as well as between the 5th and 6th column. While the jump between the third and fourth row is likely correlated with the large spatial distance between the wavelengths of the lines in the detector, there is no apparent reason why there should be such a jump between the 5th and 6th column. This raises the question of if there is an issue with previous analysis, and if so, how it effects previous results. This ticket is to determine what is causing the issue and address these concerns.</p> PIPE2D-624

Resolve discontinuity in 2D FRD residuals

Story Normal Done Done Brent Belland Brent Belland Tue, 18 Aug 2020 00:23:55 +0000 Mon, 4 Jan 2021 20:23:20 +0000 Fri, 4 Sep 2020 22:32:13 +0000 0 1 <p>The wavefronts at each position of the detector have been calculated and compared to those of <a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-489" title="Characterize the RMS wavefront across the detector " class="issue-link" data-issue-key="PIPE2D-489"><del>PIPE2D-489</del></a>, since (1) wavefront differences likely drive the FRD residuals, and (2) discrepancies between these wavefronts and those in <a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-489" title="Characterize the RMS wavefront across the detector " class="issue-link" data-issue-key="PIPE2D-489"><del>PIPE2D-489</del></a>, made from the same data set, would indicate an issue with wavefront incorporation in my FRD code. Wavefront_test2.png demonstrates the wavefronts I extracted, which qualitatively mirror that from <a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-489" title="Characterize the RMS wavefront across the detector " class="issue-link" data-issue-key="PIPE2D-489"><del>PIPE2D-489</del></a>. The FRD residual jump in 2DResidualsTotal.png between the third and fourth rows is also correlates with a large wavefront change between these rows. No clear reason driving the 5th and 6th column jump is apparent, however.</p> <p>PSFs with and without the masking due to the camera, spiders, and slit were compared; these likely do not drive the large residual jump.</p> <p>No_Recentering.png displays the residuals in 2D across the detector when the recentering algorithm is not implemented in the code. The most immediately noticeable trait is the continuity of the residual magnitudes across the detector across columns. This raises the strong possibility that the PSF alignment introduces the large discontinuity seen in No_Recentering.png. While recentering attempts in the oversampled regions were attempted, they failed due to poor downsampling implementation. Thus resulting in recentering in the downsampled region. Of course, recentering in the downsampled region can lead to artifacts in the image that may manifest with enough of a change in the initial centroid (which correlates with detector position). Currently I am rewriting my recentering code for the oversampled data after advice from Neven; the hope is that incorporating this will resolve this issue.</p> <p>It should be noted that a similarly continuous 2D residual distribution across the detector was found when setting the z4, z11, and z22 components of the wavefront to 0; however, these circularly symmetric Zernikes were not expected to be the cause of the strong asymmetry of residual magnitudes across the 5th and 6th columns.</p> <p>2D_ZeroCenter.png shows the 2D residuals when the center of the illumination and the fiber are set to have zero offset. Notably, the discontinuity in the 2D residuals is not present in this figure, indicating that the fiber-illumination offset was driving the discontinuity.</p> Blocks PIPE2D-602 PIPE2D-613 Relates PIPE2D-625 Development Rank 0|02qps2:m Sprint 2DDRP-2021 A