FixedSamplingImagePlaneElement

class poppy.FixedSamplingImagePlaneElement(name='unnamed FPM element', transmission=None, opd=None, opdunits=None, planetype=PlaneType.intermediate, wavelength_c=None, entrance_pupil_diam=None, pixelscale=None, centering='ADJUSTABLE', **kwargs)

Bases: FITSOpticalElement

This class allows the definition of focal plane masks using .fits files that will be applied to a wavefront via an FFT/MFT sequence to achieve the correct sampling at the assumed focal plane.

This element will only function as an intermediate planetype due to pixelscale and display functionality when propagating to this plane. Note: if an image planetype were to be used, the wavefront at this plane may have infinite pixelscales, making it impossible to display the wavefront with extents.

The method used to apply this element requires additional information from the user that is not required for FITSOpticalElements. These additional parameters are listed below.

Parameters not in FITSOpticalElement

wavelength_c: astropy.quantity

Central wavelength of the user’s system, required in order to convert the pixelscale to units of lambda/D and scale the pixelscale of the element based on the wavelength being propagated. If this parameter is left as None, the pixel scale can be read from the FITS header keyword PIXELSCL, if that keyword exists in the provided file.

entrance_pupil_diam: astropy.quantity

Entrance pupil diameter of the system, required to convert the pixelscale to units of lambda/D. If this parameter is left as None, the pixel scale can be read from the FITS header keyword PIXELSCL, if that keyword exists in the provided file.

pixelscale: float

pixelscale value in units of arcsec/pix. If this parameter is left as None, the pixel scale can be read from the FITS header keyword PIXELSCL, if that keyword exists in the provided file.

centering: str

What type of centering to use for the MFTs, see MFT documentation for more information. Default is ‘ADJUSTABLE’.