atlas-fit 1.0.3

Tool to perform comparison and calibration of flat fielded flat images against a solar atlas.

Atlas-Fit

Python tools to fit solar spectra with known atlantes for

• wavelength calibration
• continuum correction
• stray-light analysis
• effective FWHM computation
• chi^2 error computation of the atlas fit

This package provides two tools:

• bin/prepare:
  This script is used to generate a list of lines from the atlas and data to use for finding a wavelength solution (dispersion). If you have a list of lines already you can still use this to test and fine-tune your configuration and to inspect the fitting and analysis results with interactive plots.
• bin/amend_spectroflat:
  This tool allows to amend the calibration results from the spectroflat library. The fitted dispersion can be applied to the OffsetMap (to include wavelength calibration) and the continuum correction can be included with the soft-flat.

Both tools can (and should) be run with the same configuration. Run the prepare first to find the right configuration values and use the amend_spectroflat script to apply the results.

When using this library please cite:

Hoelken et al. "Spectroflat: A generic spectrum and flat-field calibration library for spectro-polarimetric data" (DOI: 10.1051/0004-6361/202348877)

Configuration

Lines to be used for dispersion fitting can be selected interactively: After the prepare script ran successful on the selected lines, it will create an atlas_fit_lines.yaml configuration file to be used with amend_spectroflat script. Find an example under examples/line_selection.yml

label: "Test config"
input:
  path: examples/test.fits.gz
  roi: "[25,10:]"
  wl_start: 410.6
  wl_end: 413.4
  fwhm: 0.00112
  stray_light: 7
  line_window: 12

atlas:
  key: 'hhdc'
  line_window: 50

Find a fully commented example under examples/config.yml

Usage

Run either script with <script-name> path/to/config.yml [path/to/linefile.yml]

prepare

This script allows you to inspect the fit of your data against the selected atlas and lines in detail. Use this to fine-tune the configuration and generate plots.

amend_spectroflat

This script creates an improved version of the calibration data created with spectroflat. It will add the dispersion correction (and error information) to the OffsetMap and the continuum correction to the soft flat.

Using the amended calibration data results in a fully corrected dataset suitable for demodulation and spectral restoration.

Support

Developed and maintained by [e-mail]