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/INSTRM-2150 Instrument control development <p>During the MCS alignment, we used MPFIT for fitting 2D gaussian function to determine the spot sizes. We were expecting to use the second moments from database table `mcs_data`. However, the FWHMs calculated from second moments are not consistent with MPFIT of Python and IDL version. We should double check the consistency, so that we can use those information for MCS image quality check.</p> INSTRM-2150

Inconsistency of the second moments of MCS centroid measurement

Task Normal Open Unresolved karr chyan Thu, 18 Jan 2024 21:06:04 +0000 Wed, 24 Jan 2024 00:27:11 +0000 ics_mcsActor 0 2 <p>Attached image is spot 1743 of frame 10504000. According to the data base entry, the second moments are 1.249642, 3.701665, which lead the FWHM = 2.63259298, 4.53095207. However, MPFIT of python and IDL version give sigma = 0.98, 1.26 (FWHM = 2.3079, 2.9673). These numbers are not consistent. </p> <p>This is expected. The MCS code uses a windowed second moment, not an isophotal (like the default sextractor) or a fitted function (like MPFIT), and we don't expect them to be the same, although they will show similar relative behaviour. </p> Development Rank 0|02qpjd:00r20060i200186403r7i3yf