<p>I'm working on the ring diagram technique and pipeline for the Solar Dynamics Observatory's <a href="https://en.wikipedia.org/wiki/Solar_Dynamics_Observatory#Helioseismic_and_Magnetic_Imager_(HMI)" rel="nofollow noreferrer">Helioseismic and Magnetic Imager</a> or HMI, but I didn't find much about the details about how it works or how to obtain the data.</p>

<p>I know that all starts with measuring <a href="https://en.wikipedia.org/wiki/Dopplergraph" rel="nofollow noreferrer">Dopplergrams</a> and then doing something call Postel's projection, then the apodization, then the 3D Fourier transform to obtain the 3D power spectra where there are 2 forms of adjust to each ring separately (FITSC and FITSF, both done by the HMI's pipeline).</p>

<p>I need more details about how all this process is done, does anyone know? Or could indicate me some references?</p>

CC BY-SA 4.0
2020-05-25T20:34:17.200Z
It isn't clear (to me) what your question is about
ProfRob
CC BY-SA 4.0
2020-05-25T21:15:38.870Z
It's about heilioseismology, this tecnique is used to determine subsurface flows in sun. And HMI is the satellite where all the data comes from
Vanessa
CC BY-SA 4.0
2020-05-26T01:14:56.243Z
I've added some information back into your question, please feel free to edit further and Welcome to Stack Exchange!
uhoh
<the-sun><data-analysis><space-telescope>
Does anyone know about the ring diagram technique and Helioseismic and Magnetic Imager pipeline?
Vanessa
# Does anyone know about the ring diagram technique and Helioseismic and Magnetic Imager pipeline?

(Asked by: username_0 on 2020-05-25)

I'm working on the ring diagram technique and pipeline for the Solar Dynamics Observatory's [Helioseismic and Magnetic Imager](https://en.wikipedia.org/wiki/Solar_Dynamics_Observatory#Helioseismic_and_Magnetic_Imager_(HMI)) or HMI, but I didn't find much about the details about how it works or how to obtain the data.

I know that all starts with measuring [Dopplergrams](https://en.wikipedia.org/wiki/Dopplergraph) and then doing something call Postel's projection, then the apodization, then the 3D Fourier transform to obtain the 3D power spectra where there are 2 forms of adjust to each ring separately (FITSC and FITSF, both done by the HMI's pipeline).

I need more details about how all this process is done, does anyone know? Or could indicate me some references?

**Tags:** the-sun, data-analysis, space-telescope

> **Comments:**
> **username_1**: It isn't clear (to me) what your question is about  
> **username_0**: It's about heilioseismology, this tecnique is used to determine subsurface flows in sun. And HMI is the satellite where all the data comes from  
> **username_2**: I've added some information back into your question, please feel free to edit further and Welcome to Stack Exchange!  

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## 0 answers

