roman_shear_sims.wcs

Functions

get_SCA_WCS(world_pos, SCA[, PA, img_size])

Get the WCS for a specific SCA at a given world position.

get_IMCOM_WCS(world_pos[, img_size, as_astropy])

Create a WCS for IMCOM coadds.

make_simple_exp_wcs(world_pos[, PA, img_size])

Create a simple WCS for an exposure with a given world position and

make_simple_coadd_wcs(world_pos, img_size[, as_astropy])

Create a simple WCS for a coadd image with a given world position and

make_oversample_local_wcs(wcs, world_pos, oversamp_factor)

Create an oversampled local WCS from a given WCS and world position.

Module Contents

get_SCA_WCS(world_pos, SCA, PA=0.0, img_size=None)[source]

Get the WCS for a specific SCA at a given world position. This function is derived from: https://github.com/GalSim-developers/GalSim/blob/4c04a1ea4aa4c652c25019c0c7b5881f7571035f/galsim/roman/roman_wcs.py#L88

Parameters:

  • world_pos (galsim.CelestialCoord) – The celestial coordinates of the image center.

  • SCA (int) – The SCA number.

  • PA (float, optional) – The position angle in degrees.

  • img_size (int, optional) – The size of the image in pixels. If None, defaults to roman.n_pix.

Returns:

The WCS object for the specified SCA.

Return type:

galsim.BaseWCS

get_IMCOM_WCS(world_pos, img_size=None, as_astropy=False)[source]

Create a WCS for IMCOM coadds.

Parameters:

  • world_pos (galsim.CelestialCoord) – The celestial coordinates of the image center.

  • img_size (int, optional) – The size of the image in pixels. If None, defaults to IMCOM_BLOCK_SIZE.

  • as_astropy (bool, optional) – If True, return the WCS as an Astropy WCS object. Default is False.

Returns:

The WCS object for the IMCOM coadd image.

Return type:

galsim.BaseWCS

make_simple_exp_wcs(world_pos, PA=0.0, img_size=None)[source]

Create a simple WCS for an exposure with a given world position and position angle.

Parameters:

  • world_pos (galsim.CelestialCoord) – The celestial coordinates of the image center.

  • PA (float, optional) – The position angle in degrees. Default is 0.0.

  • img_size (int, optional) – The size of the image in pixels. If None, defaults to roman.n_pix.

Returns:

The WCS object for the exposure.

Return type:

galsim.WCS

make_simple_coadd_wcs(world_pos, img_size, as_astropy=False)[source]

Create a simple WCS for a coadd image with a given world position and image size.

Parameters:

  • world_pos (galsim.CelestialCoord) – The celestial coordinates of the image center.

  • img_size (int) – The size of the image in pixels.

  • as_astropy (bool, optional) – If True, return the WCS as an Astropy WCS object. Default is False.

Returns:

The WCS object for the coadd image.

Return type:

galsim.WCS or astropy.wcs.WCS

make_oversample_local_wcs(wcs, world_pos, oversamp_factor)[source]

Create an oversampled local WCS from a given WCS and world position.

Parameters:

  • wcs (galsim.WCS) – The original WCS object.

  • world_pos (galsim.CelestialCoord) – The celestial coordinates of the image center.

  • oversamp_factor (int) – The oversampling factor to apply to the WCS.

Returns:

The oversampled WCS object.

Return type:

galsim.WCS