polarization calibration of hmi
Download
Skip this Video
Download Presentation
Polarization Calibration of HMI

Loading in 2 Seconds...

play fullscreen
1 / 7

Polarization Calibration of HMI - PowerPoint PPT Presentation


  • 102 Views
  • Uploaded on

Polarization Calibration of HMI. A. Norton, J. Schou, D. Elmore, J. Borrero, S. Tomczyk, G. Card + High Altitude Observatory National Center for Atmospheric Research. Polarization Modulation Schemes. Mod A - 4 observations mix linear & circular (80 sec) I Q U V

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Polarization Calibration of HMI' - apu


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
polarization calibration of hmi
Polarization Calibration of HMI
  • A. Norton, J. Schou, D. Elmore,
  • J. Borrero, S. Tomczyk, G. Card +
  • High Altitude Observatory
  • National Center for Atmospheric Research
polarization modulation schemes
Polarization Modulation Schemes

Mod A - 4 observations mix linear & circular (80 sec)

I Q U V

I Q U V

Mod C - 6 obs separate linear & circular

I±Q, I±U, I±V (120 sec)

Can correct for velocity during Mod C.

polarization calibration unit pcu g card d elmore s tomczyk k streander
Polarization Calibration Unit (PCU)G. Card, D. Elmore, S. Tomczyk, K. Streander +

Linear Polarizer & a 1/4 Waveplate:

*Moved in/out of beam (1.25  resolution)

*Rotate optics (0.001° resolution)

Inputs fixed states of polarization into HMI for calibration purposes

slide4

PCU

HMI Tel

HMI Polarizer

Sout

Sin

Lin 1/4

Pol WP

1/2 1/4 1/2 Lin

WP WP WP Pol

HMI Tel

Ret (,)

17 Unknowns in optical path:

3 - Input light - Slamp= ([1.0], [q], [u], [v])

4 - PCU - transmissions, retardation error and mount error of WP

2 - HMI tel - retardation and angle

6 - HMI Polarizer - mount errors and retardation errors for WPs, 2 - CCD - gain, bias

calculating thet matrix polarimeter response matrix
Calculating theT-Matrix & Polarimeter Response Matrix
  • Calibration sequences selected to constrain unknowns: With PCU elements in/out of beam and at various angles, step through a variety of HMI waveplate orientations. Short sequence - 69 exposures, includes Mod A Long sequence - 140 exposures, includes Mod C.
  • Forward model light path.
  • Use least squares fitting routine to solve for unknowns.
  • Combine for Telescope matrix & Polarimeter Response Matrix.
monte carlo simulations photon noise
Monte Carlo Simulations - Photon Noise

Calibration requirement are

that uncertainties in [XT] < 0.1%

calibration in progress
Calibration in Progress

Polarization data taken Feb 9-10

With PCU in beam. Work in progress.

Please check HAO website for updates

http://web.hao.ucar.edu/hmi

1st magnetogram 2/7/06 courtesy of J. Schou

ad