corgidrp.flat#

Functions#

create_flatfield(flat_dataset)

Turn this dataset of image frames that were taken for performing the flat calibration and

raster_kernel(width, image[, hard])

Convolution kernel to create flat field circular raster pattern

flatfield_residuals(dataset[, N])

Turn this dataset of image frames of neptune or uranus and create matched filters and estimate residuals after

combine_flatfield_rasters(resi_images_dataset[, cent, ...])

combine the dataset of residual image frames of neptune or uranus and create flat field

create_onsky_flatfield(dataset[, planet, band, ...])

Turn this dataset of image frames of uranus or neptune raster scannned that were taken for performing the flat calibration and create one master flat image.

create_onsky_pol_flatfield(dataset[, planet, band, ...])

Turn this dataset of image frames of uranus or neptune raster scannned that were taken for performing the flat calibration and create one master flat image.

Module Contents#

corgidrp.flat.create_flatfield(flat_dataset)[source]#

Turn this dataset of image frames that were taken for performing the flat calibration and to make one master flat image this is currently a placeholder, until the final flat fielding calibration package is completed.

Parameters:

flat_dataset (corgidrp.data.Dataset) – a dataset of Image frames (L2a-level)

Returns:

a master flat for flat calibration

Return type:

flat_field (corgidrp.data.FlatField)

corgidrp.flat.raster_kernel(width, image, hard=True)[source]#

Convolution kernel to create flat field circular raster pattern

Parameters:

  • width (float) – radius of circular raster in pixels

  • image (np.array) – 2-D image to specify the full size of the kernel needed

  • hard (bool) – if true, use hard edge kernel, otherwise, use Gaussian tapered kernel

Returns:

smoothing kernel value at each pixel

Return type:

np.array

corgidrp.flat.flatfield_residuals(dataset, N=None)[source]#

Turn this dataset of image frames of neptune or uranus and create matched filters and estimate residuals after dividing from matched filters

Parameters:

  • dataset (corgidrp.data.Dataset) – dataset of cropped neptune or uranus image frames

  • N (int) – number of images to be grouped. defaults to 3 for both Neptune and uranus. (If we use different number of dithers for neptune and uranus, option is provided to change N)

Returns:

dataset of neptune or uranus images divided by matched filter

Return type:

matched_residuals_dataset (corgidrp.data.Dataset)

corgidrp.flat.combine_flatfield_rasters(resi_images_dataset, cent=None, planet=None, band=None, im_size=420, rad_mask=None, planet_rad=None, n_pix=165, n_pad=302, image_center_x=512, image_center_y=512)[source]#

combine the dataset of residual image frames of neptune or uranus and create flat field and associated error

Parameters:

resi_images_dataset – dataset of residual images of uranus or Neptune

Returns:

flat field created from uranus or neptune images err_residuals (np.array): Error in the flatfield estimated using the ideal flat field

Return type:

full_residuals (np.array)

cent_n (np.array): centroid of the combined image

corgidrp.flat.create_onsky_flatfield(dataset, planet=None, band=None, up_radius=55, im_size=None, N=1, rad_mask=None, planet_rad=None, n_pix=44, n_pad=None, sky_annulus_rin=2, sky_annulus_rout=4, image_center_x=512, image_center_y=512)[source]#

Turn this dataset of image frames of uranus or neptune raster scannned that were taken for performing the flat calibration and create one master flat image. The input image frames are L2b image frames that have been dark subtracted, divided by k-gain, divided by EM gain, desmeared.

Args:

dataset (corgidrp.data.Dataset): a dataset of image frames of uranus or neptune that are raster scanned (L2a-level) planet (str): neptune or uranus band (str): 1 or 4 up_radius (int): Number of pixels on either side of centroided planet images (=55 pixels for Neptune and uranus) im_size (int): x-dimension of the input image (in pixels; default is size of input dataset; = 420 for the HST images) N (int): Number of images to be combined for creating a matched filter (defaults to 1, may not work for N>1 right now) rad_mask (float): radius in pixels used for creating a mask for band (band1=1.25, band4=1.75) planet_rad (int): radius of the planet in pixels (planet_rad=50 for neptune, planet_rad=65) n_pix (int): Number of pixels in radius covering the Roman CGI imaging FOV (defaults to 44 pix for Band1 HLC; 165 pixels for full shaped pupil FOV). n_pad (int): Number of pixels padded with ‘1s’ to generate the image size 1024X1024 pixels around imaging FOV (defaults to None; rest of the FOV to reach 1024) sky_annulus_rin (float): Inner radius of annulus to use for sky subtraction. In units of planet_rad.

If both sky_annulus_rin and sky_annulus_rout = None, skips sky subtraciton.

sky_annulus_rout (float): Outer radius of annulus to use for sky subtraction. In units of planet_rad. image_center_x (int): x coordinate of the center pixel of the final image image_center_y (int): y coordinate of the center pixel of the final image

Returns:

data.FlatField (corgidrp.data.FlatField): a master flat for flat calibration using on sky images of planet in band specified

corgidrp.flat.create_onsky_pol_flatfield(dataset, planet=None, band=None, up_radius=55, im_size=None, N=1, rad_mask=None, planet_rad=None, n_pix=None, observing_mode='NFOV', n_pad=None, fwhm_guess=20, sky_annulus_rin=2, sky_annulus_rout=4, plate_scale=0.0218, image_center_x=512, image_center_y=512, separation_diameter_arcsec=7.5, alignment_angle_WP1=0, alignment_angle_WP2=45, dpamname=None)[source]#

Turn this dataset of image frames of uranus or neptune raster scannned that were taken for performing the flat calibration and create one master flat image. The input image frames are L2b image frames that have been dark subtracted, divided by k-gain, divided by EM gain, desmeared.

Args:

dataset (corgidrp.data.Dataset): a dataset of image frames that are raster scanned (L2a-level) planet (str): neptune or uranus band (str): 1 or 4 up_radius (int): Number of pixels on either side of centroided planet images (=55 pixels for Neptune and uranus) im_size (int): x-dimension of the input image (in pixels; default is size of input dataset; = 420 for the HST images) N (int): Number of images to be combined for creating a matched filter (defaults to 1, may not work for N>1 right now) rad_mask (float): radius in pixels used for creating a mask for band (band1=1.25, band4=1.75) planet_rad (int): radius of the planet in pixels (planet_rad=50 for neptune, planet_rad=65) n_pix (int): Number of pixels in radius covering the Roman CGI imaging FOV (defaults to 44 pix for Band1 HLC; 165 pixels for full shaped pupil FOV). observing_mode (string): observing mode of the coronagraph n_pad (int): Number of pixels padded with ‘1s’ to generate the image size 1024X1024 pixels around imaging FOV (defaults to None; rest of the FOV to reach 1024) fwhm_guess (int):FWHM guess for the planet image which is downsampled by a factor of 8 sky_annulus_rin (float): Inner radius of annulus to use for sky subtraction. In units of planet_rad.

If both sky_annulus_rin and sky_annulus_rout = None, skips sky subtraciton.

sky_annulus_rout (float): Outer radius of annulus to use for sky subtraction. In units of planet_rad. plate_scale (float): platescale estimated from calibration (0.0218) image_center_x (int): x coordinate of the center pixel of the final image with two orthogonal pol components image_center_y (int): y coordinate of the center pixel of the final image with two orthogonal pol components separation_diameter_arcsec (float): separation between the two orthogonal pol components in arcsecs alignment_angle_WP1 (int): wollaston prism angle for Pol0 - 0 alignment_angle_WP2 (int): wollaston prism angle for Pol45- 45 dpamname (str): wollaston prism POL0 or POL45. Defaults to DPAMNAME in the header.

Returns:

data.FlatField (corgidrp.data.FlatField): a master flat corresponding to Pol0 or Pol 45 for flat calibration using on sky images of planet in band specified