1 / 5

S/N and Polarimetry With HMI

S/N and Polarimetry With HMI. Bruce W. Lites High Altitude Observatory National Center for Atmospheric Research HMI Team Meeting, Palo Alto, 1-2 May 2003. 2 May 2003. Significant Considerations for S/N and Accuracy of Vector Magnetic Field Inversions. Results are compromised by:.

cpatel
Download Presentation

S/N and Polarimetry With HMI

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. S/N and Polarimetry With HMI Bruce W. Lites High Altitude Observatory National Center for Atmospheric Research HMI Team Meeting, Palo Alto, 1-2 May 2003 2 May 2003

  2. Significant Considerations for S/N and Accuracy of Vector Magnetic Field Inversions Results are compromised by: • Spectral resolution • Spectral sampling • Noise level • Detector full-well issues: non-linearity, intensity margin • Duty cycle of instrument • Accuracy of measured instrument spectral profile Bruce Lites, HMI Team Mtg., 2 May 2003

  3. Noise Simulations with ASP Data

  4. Realistic Simulations? • HMI Vector field tests so far only indicate the best case: inversions are initialized from the solution, or very close to it • Realistic simulations must account for the issue of initialization • New pattern recognition techniques (principal components analysis, neural network, support vector machine) do not rely on initial guess, but also may substantially “miss” the solution if the data are too noisy

  5. Recommendation • With the HMI CCD source now in question, an opportunity exists to examine the choices for detectors with a view of larger full-well capacity, or • With Solar-B, the technology exists for space instrumentation to do rapid readout/summing of images

More Related