PowerSpectrumWFE
- class poppy.PowerSpectrumWFE(name='Model PSD WFE', psd_parameters=None, psd_weight=None, seed=None, apply_reflection=False, screen_size=None, rms=None, incident_angle=<Quantity 0. deg>, radius=None, **kwargs)[source]
Bases:
WavefrontErrorWFE model specified via a Power Spectral Density (PSD), or a list of multiple PSDs, which follow von Karman PSD model:
\(P(k) = \frac{\beta} {\left( \left(\frac{1}{L_{0}}\right)^{2} + |k|^{2} \right)^{{\alpha/2}}} e^{-(|k|l_{0})^{2}} + \beta_{sr}\)
where: P: astropy quantity
Power Spectral Density at a spatial frequency. Units: :math:
m^{2}m^{2}Assumes surface units of meters (first :math:m^{2})- k: astropy quantity
Spatial frequency value, units 1/m
- \(\alpha\): float
The PSD index value
- \(\beta\): astropy quantity
The normalization constant. In units of :math:
frac{m^{2}}{m^{alpha-2}}Numerator assumes surface units of meters Denominator assumes spatial frequency units are 1/m- \(L_{0}\): astropy quantity
The outer scale value, where the low spatial frequency flattens. Units: m
- \(l_{0}\): float
Inner scale value, where the high spatial frequency flattens.
- \(\beta_{sr}\): astropy quantity
Surface roughness normalization. Should match units of PSD.
References: Males, Jared. MagAO-X Preliminary-Design Review,
Section 5.1: Optics Specifications, Eqn 1 https://magao-x.org/docs/handbook/appendices/pdr/
Lumbres, et al. In Prep.
- Parameters:
- namestring
name of the optic
- psd_parameters: list (for single PSD set) or list of lists (multiple PSDs)
List of specified PSD parameters. If there are multiple PSDs, then each list element is a list of specified PSD parameters. i.e. [ [PSD_list_0], [PSD_list_1]] The PSD parameters in a list are ordered as follows: [alpha, beta, outer_scale, inner_scale, surf_roughness] where:
- alpha: float
The PSD index value.
- beta: astropy quantity
The normalization constant. In units of :math:
frac{m^{2}}{m^{alpha-2}}Numerator assumes surface units of meters Denominator assumes spatial frequency units are 1/m- outer_scale: astropy quantity
The outer scale value, where the low spatial frequency flattens. Unit requirement: meters
- inner_scale: float
Inner scale value, where the high spatial frequency flattens.
- surf_roughness: astropy quantity
Surface roughness normalization. Should match units of PSD.
- psd_weight: iterable list of floats
Specifies the weight multiplier to set onto each model PSD
- seedinteger
Seed for the random phase screen generator
- apply_reflection: boolean
Applies 2x scale for the OPD as needed for reflection. Default to False. Set to True if the PSD model only accounts for surface.
- screen_size: integer
Sets how large the PSD matrix will be calculated. The PSD matrix needs to be larger than the wavefront for Fourier transform padding purposes. If None passed in, then code will default size to 4x wavefront’s side. Default to None.
- rms: astropy quantity
Optional. Use this to force the wfe RMS If a value is passed in, this is the surface rms value (not OPD) in meters. If None passed, then the wfe RMS produced is what shows up in PSD calculation. Default to None.
- incident_angle: astropy quantity
Adjusts the WFE based on reflected beam distortion. Does not distort the beam (remains circular), but will get the rms equivalent value. Can be passed as either degrees or radians. Default is 0 degrees (paraxial).
- radius: astropy quantity
Optional. However, mandatory if rms parameter is passed. If a value is passed in, this is the beam radius value for calculating the generated WFE rms to compare with the normalized rms value. Default to None.
Methods Summary
get_opd(wave)Methods Documentation