SDO/HMI line-of-sight Dopplergram, 720-Second Data
Description
Dopplergrams are maps of solar surface velocity. The HMI (Camera 2) instrument takes 72 filtergrams to construct a single dopplergram. Six filtergrams are taken in six positions across the nominal 6173.3 Å spectral line; each filtergram is taken in two polarization states (right circularly polarized (RCP), or Stokes I-V, and left circularly polarized (LCP), or I+V). Assuming that the absorption line is a Gaussian and that the HMI filter transmission profiles are delta functions, the Fourier coefficients can be calculated and are then used to estimate the line-of-sight magnetic field strength B.
Resources
| Name |
Format |
Description |
Link |
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5 |
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http://jsoc.stanford.edu/ajax/lookdata.html?ds=hmi.V_720s%5B2020-01-01T00%3A00%3A00%2F60m%5D |
|
5 |
|
https://sdac.virtualsolar.org/cgi/search?time=1&instrument=HMI&spectrum=1&version=current&build=1 |
|
5 |
|
http://hmi.stanford.edu/ |
|
21 |
|
https://doi.org/10.1007/s11207-011-9834-2 |