resampled_wcs_from_models

jwst.resample.resample_utils.resampled_wcs_from_models(input_models, pixel_scale_ratio=1.0, pixel_scale=None, output_shape=None, rotation=None, crpix=None, crval=None)[source]

Compute the WCS of the resampled image from input models and specified WCS parameters.

Parameters:

  • input_models (ModelLibrary) – Each datamodel must have a model.meta.wcs set to a ~gwcs.WCS object.

  • pixel_scale_ratio (float, optional) – Desired pixel scale ratio defined as the ratio of the desired output pixel scale to the first input model’s pixel scale computed from this model’s WCS at the fiducial point (taken as the ref_ra and ref_dec from the wcsinfo meta attribute of the first input image). Ignored when pixel_scale is specified.

  • pixel_scale (float, None, optional) – Desired pixel scale (in degrees) of the output WCS. When provided, overrides pixel_scale_ratio.

  • output_shape (tuple of two integers (int, int), None, optional) – Shape of the image (data array) using np.ndarray convention (ny first and nx second). This value will be assigned to pixel_shape and array_shape properties of the returned WCS object.

  • rotation (float, None, optional) – Position angle of output image’s Y-axis relative to North. A value of 0.0 would orient the final output image to be North up. The default of None specifies that the images will not be rotated, but will instead be resampled in the default orientation for the camera with the x and y axes of the resampled image corresponding approximately to the detector axes. Ignored when transform is provided.

  • crpix (tuple of float, None, optional) – Position of the reference pixel in the resampled image array. If crpix is not specified, it will be set to the center of the bounding box of the returned WCS object.

  • crval (tuple of float, None, optional) – Right ascension and declination of the reference pixel. Automatically computed if not provided.

Returns:

  • wcs (~gwcs.wcs.WCS) – The WCS object corresponding to the combined input footprints.

  • pscale_in (float) – Computed pixel scale (in degrees) of the first input image.

  • pscale_out (float) – Computed pixel scale (in degrees) of the output image.

  • pixel_scale_ratio (float) – Pixel scale ratio (output to input).