fft_image_to_griddata_with_wcs

fft_image_to_griddata_with_wcs(im)[source]

WCS-aware FFT of a canonical image

The only transforms supported are:

RA–SIN, DEC–SIN <-> UU, VV XX, YY <-> KX, KY

For example:

from rascil.processing_components import
    create_test_image, fft_image_to_griddata_with_wcs
im = create_test_image()
print(im)
    Image:
        Shape: (1, 1, 256, 256)
        WCS: WCS Keywords
    Number of WCS axes: 4
    CTYPE : 'RA---SIN'  'DEC--SIN'  'STOKES'  'FREQ'
    CRVAL : 0.0  35.0  1.0  100000000.0
    CRPIX : 129.0  129.0  1.0  1.0
    PC1_1 PC1_2 PC1_3 PC1_4  : 1.0  0.0  0.0  0.0
    PC2_1 PC2_2 PC2_3 PC2_4  : 0.0  1.0  0.0  0.0
    PC3_1 PC3_2 PC3_3 PC3_4  : 0.0  0.0  1.0  0.0
    PC4_1 PC4_2 PC4_3 PC4_4  : 0.0  0.0  0.0  1.0
    CDELT : -0.000277777791  0.000277777791  1.0  100000.0
    NAXIS : 0  0
        Polarisation frame: stokesI
print(fft_image_to_griddata_with_wcs(im))
    Image:
        Shape: (1, 1, 256, 256)
        WCS: WCS Keywords
    Number of WCS axes: 4
    CTYPE : 'UU'  'VV'  'STOKES'  'FREQ'
    CRVAL : 0.0  0.0  1.0  100000000.0
    CRPIX : 129.0  129.0  1.0  1.0
    PC1_1 PC1_2 PC1_3 PC1_4  : 1.0  0.0  0.0  0.0
    PC2_1 PC2_2 PC2_3 PC2_4  : 0.0  1.0  0.0  0.0
    PC3_1 PC3_2 PC3_3 PC3_4  : 0.0  0.0  1.0  0.0
    PC4_1 PC4_2 PC4_3 PC4_4  : 0.0  0.0  0.0  1.0
    CDELT : -805.7218610503596  805.7218610503596  1.0  100000.0
    NAXIS : 0  0
        Polarisation frame: stokesI
Parameters:

im

Returns:

See also

ska_sdp_func_python.fourier_transforms.fft_support.fft() ska_sdp_func_python.fourier_transforms.fft_support.ifft()