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-463 DRP 2-D Pipeline <p>During technical telecon on Oct 14, I claimed that diagonal stripes seen in the image in <a href="https://pfspipe.ipmu.jp/jira/browse/PIPE2D-462" title="Create a scattering kernel" class="issue-link" data-issue-key="PIPE2D-462"><del>PIPE2D-462</del></a> are due to aliasing. Check this assertion. I also claimed that effect is too small to be seen in the real images, while it can clearly be seen in the mentioned figure, even after applying scattering that I claim is representative of the real amount of scattering. Investigate.</p> PIPE2D-463

Aliasing effects in 2d PSF

Task Normal Done Done ncaplar ncaplar Tue, 15 Oct 2019 14:50:33 +0000 Tue, 12 Nov 2019 15:11:53 +0000 Tue, 12 Nov 2019 15:11:53 +0000 0 1 <p>(paging <a href="https://pfspipe.ipmu.jp/jira/secure/ViewProfile.jspa?name=rhl" class="user-hover" rel="rhl">rhl</a>, just FYI)</p> <p>For all images, the physical scale of the image is roughly 375 microns (25 pixels on the detector).</p> <p>FFT_effects_without_apodization.png shows how different pupil create different PSFs. I show the different component arising from the 3 types of the obscuration that are present in the system (detector, struts, slit+slit holder). As we suspected the crossing patter is due to the struts. </p> <p>FFT_effects_witg_apodization.png shows the results after I applied a little bit of apodization, by convolving the pupil with the Gaussian with the sigma of 0.75 pixels. We see that the reflection is diminished.</p> <p>I played with this a lot before already.... I feel a bit uneasy to introduce a custom apodization, i.e., to just pick a number with which to convolve the pupil but perhaps there is no better options. If the sigma is small, then the cost of the convolving is not too high and this could be introduced in the current algorithm. </p> <p> </p> <p>Resulting images look ``fine'' when analyzed on cluster in early November 2019</p> Relates PIPE2D-462 Development Rank 0|02qpt6:508yl0chzzy Sprint 2DDRP-2019 I Story Points 2.0