Campuses:
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| 20180420_pysm_smooth [2018/04/20 11:32] – pryke | 20180420_pysm_smooth [2018/04/20 11:51] (current) – pryke | ||
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| (See [https:// | (See [https:// | ||
| - | PySM can be run at any nside up to 512. What it does internally I have not investigated. It can also be told to smooth the output maps to a given beam size. | + | PySM can be run at any nside up to 512. What it does internally |
| To be realistic we would generate PICO maps with the resolution varying by band as per [[imageroptions]]. | To be realistic we would generate PICO maps with the resolution varying by band as per [[imageroptions]]. | ||
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| Here is the PySM map at 150 GHz for model a2d4f1s3 in T: | Here is the PySM map at 150 GHz for model a2d4f1s3 in T: | ||
| - | {{: | + | {{: |
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| + | Now I turn on smoothing with 120 arcmin kernel and take the difference of smoothed minus unsmoothed: | ||
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| + | {{:20180420_fig2.gif}} | ||
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| + | We see severe artifacts which results from the harmonic space manipulation of a map which has bright galactic plane. | ||
| + | The dynamic range is smaller in polarization but there is still a problem. | ||
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| + | We need to decide how to deal with this. Some options | ||
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| + | 1) The galactic plane will always get masked in post analysis anyway - we could just pre-mask it before smoothing (this is what I did for CMB-S4 sims concerned only with small patch at high latitude. | ||
| + | 2) We could do some preliminary nside=16 sims with no smoothing at all. | ||
| + | 3) We could implement a map space smoothing which will not suffer from such artifacts. | ||
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| + | There must be knowledge from Planck on how to deal with smoothing a map with large dynamic range - since this is true for the real maps?! | ||