tweakreg_catalog

The tweakreg_catalog module provides functions for generating catalogs of sources from images.

jwst.tweakreg.tweakreg_catalog.make_tweakreg_catalog(model, kernel_fwhm, snr_threshold, sharplo=0.2, sharphi=1.0, roundlo=-1.0, roundhi=1.0)[source]

Create a catalog of point-line sources to be used for image alignment in tweakreg.

Parameters:
  • model (ImageModel) – The input ImageModel of a single image. The input image is assumed to be background subtracted.
  • kernel_fwhm (float) – The full-width at half-maximum (FWHM) of the 2D Gaussian kernel used to filter the image before thresholding. Filtering the image will smooth the noise and maximize detectability of objects with a shape similar to the kernel.
  • snr_threshold (float) – The signal-to-noise ratio per pixel above the background for which to consider a pixel as possibly being part of a source.
  • sharplo (float, optional) – The lower bound on sharpness for object detection.
  • sharphi (float, optional) – The upper bound on sharpness for object detection.
  • roundlo (float, optional) – The lower bound on roundess for object detection.
  • roundhi (float, optional) – The upper bound on roundess for object detection.
Returns:

catalog – An astropy Table containing the source catalog.
Return type:

Table