pybsm.otf.functional.circular_aperture_OTF

pybsm.otf.functional.circular_aperture_OTF(*, u: ndarray, v: ndarray, lambda0: float, D: float, eta: float) → ndarray

IBSM Equation 3-20. Obscured circular aperture diffraction OTF.

If eta is set to 0, the function will return the unobscured aperture result.

Parameters:

  • u – angular spatial frequency coordinates (rad^-1)

  • v – angular spatial frequency coordinates (rad^-1)

  • lambda0 – wavelength (m)

  • D – effective aperture diameter (m)

  • eta – relative linear obscuration (unitless)

Returns:

H:

OTF at spatial frequency (u,v) (unitless)

Raises:
ZeroDivisionError:

if lambda0 is 0

WARNING:

Output can be nan if eta is 1.

NOTE:

You will see several runtime warnings when this code is first accessed. The issue (calculating arccos and sqrt outside of their domains) is captured and corrected np.nan_to_num