THEMIS data handling
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THEMIS data handling
Arturo López Ariste
Alberto Sainz Dalda
THEMIS MTR mode
MTR: Multiline spectropolarimetry mode
Up to 10 spectral domains observed simultaneously from 4000 Å through 13000 Å
Full freedom on scanning over the solar surface and on polarimetric modulation cycle
~1 Gbyte /hour data rate.
Some bad experiences
On the telescope:1. Observers cannot handle the raw data flow.2. Up to 75% of the observers are not at hands with raw
spectropolarimetry data3. More than 50% of the observers come to THEMIS to
“measure the magnetic field” and not Stokes parameters.
Some bad experiences
On the telescope:1. Observers cannot handle the raw data flow.2. Up to 75% of the observers are not at hands with raw
spectropolarimetry data3. More than 50% of the observers come to THEMIS to
“measure the magnetic field” and not Stokes parameters.
At BASS 2000:1. Users are not interested in raw data2. Users are not interested on Stokes parameters3. Users want magnetic field maps4. Users are not used to vector fields!
What we did/are doing
Online data reduction code: SQUV
-Quasi-automatic , quasi—real-time-Provides Stokes parameters from raw data-Handles all normal situations (above 80% success rate)-Ensures a nominal 10-3 polarimetric sensitivity.-Provides up to 10-4 at shared-risk policy
What we did/are doing
Online data reduction code: SQUV
-It is automatically launched by the telescope at the end of appropriate observing sequences-Can be downloaded for personal use under GNU-like license (www.themis.iac.es)-It is being implemented at BASS2000 for old data.
Exa
mpl
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What we did/are doing
Stokes analysis and inversion:
• GUI-tools to check profiles and build maps•GUI-tools to invert (Fe I 630 nm line, Milne-Eddington)•GUI-tools to check inversions•GUI-tools to to analyze vector fields in observer’s and local frames and investigate azimuth ambiguity
Online at the telescope, inversion launched by the acquisition systemDownloadable under GNU-like license (www.themis.iac.es)
PCA Inversion
Some bad experiences
On the telescope:1. Observers cannot handle the raw data flow.2. Up to 75% of the observers are not at hands with raw
spectropolarimetry data3. More than 50% of the observers come to THEMIS to
“measure the magnetic field” and not Stokes parameters.
At BASS 2000:1. Users are not interested in raw data2. Users are not interested on Stokes parameters3. Users want magnetic field maps4. Users are not used to vector fields!