Converting Planck data for spherical projection

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 2K views
localstarlight
Messages
2
Reaction score
0
Does anyone know how I could convert data from Planck, which appear as an oval shape, into a form that I can easily map onto a sphere (ie. a rectangular shape in 2:1 aspect ratio)?

Here is an example Planck image: http://sci.esa.int/science-e-media/img/61/Planck_CMB_Mollweide_4k.jpg

I see that NASA have something called 'Science on a Sphere' where they have taken similar data (ie. WMAP) and managed to project it onto a sphere (see here), so it must be possible!

Does anyone know the process for this?

Thanks!
 
Astronomy news on Phys.org
You'd have to get the raw FITS files from the Planck website:
http://irsa.ipac.caltech.edu/data/Planck/release_2/all-sky-maps/

These are the raw maps for each frequency. I'd suggest looking at maps from 70GHz - 217GHz for looking at the CMB. Use the full mission maps (top row).

Or, if you just want to look at the CMB (with foreground signals subtracted):
http://irsa.ipac.caltech.edu/data/P..._CMB_IQU-commander_1024_R2.02_full/index.html

You'd then need a program to visualize them. Here's one, though it may not be easy to install unless you're familiar with Linux:
https://lambda.gsfc.nasa.gov/toolbox/tb_skyviewer_ov.cfm
 
Chalnoth said:
You'd have to get the raw FITS files from the Planck website:
http://irsa.ipac.caltech.edu/data/Planck/release_2/all-sky-maps/

These are the raw maps for each frequency. I'd suggest looking at maps from 70GHz - 217GHz for looking at the CMB. Use the full mission maps (top row).

Or, if you just want to look at the CMB (with foreground signals subtracted):
http://irsa.ipac.caltech.edu/data/P..._CMB_IQU-commander_1024_R2.02_full/index.html

You'd then need a program to visualize them. Here's one, though it may not be easy to install unless you're familiar with Linux:
https://lambda.gsfc.nasa.gov/toolbox/tb_skyviewer_ov.cfm

Thanks! This is very helpful!

Is that viewer able to export a 2D map that I can then project onto a sphere in a 3D application though? From the description it sounds like you can view it on a sphere inside the program, but not necessarily export what I'm after.

Thanks again for your help.
 
localstarlight said:
Thanks! This is very helpful!

Is that viewer able to export a 2D map that I can then project onto a sphere in a 3D application though? From the description it sounds like you can view it on a sphere inside the program, but not necessarily export what I'm after.

Thanks again for your help.
I'm not familiar with any software to convert FITS to any other format that stores data for the full surface of the sphere for the purpose of projecting in 3D, unfortunately.

I know roughly how you could write such a program, but that solution will only work if you're a programmer.