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

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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!