simonsobs / nemo

Millimeter-wave map filtering and Sunyaev-Zel'dovich galaxy cluster/source detection package. Originally developed for the Atacama Cosmology Telescope project.
https://nemo-sz.readthedocs.io
BSD 3-Clause "New" or "Revised" License
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Fix pathological 1/f noise issue #72

Closed msyriac closed 3 months ago

msyriac commented 3 months ago

By default, 1/f noise becomes pathologically high as you approach ell=0. This creates unrealistic maps. In practice, the real atmosphere and the map-maker transfer function lead to zeroing of the noise on large scales. I arbitrarily set the noise for lmin<100 (default) to be zero to avoid this, and provide lmin as a parameter to simMap.

h/t: Maya Williamson-Shaffer and Eunseong Lee for finding this problem