"""
=================
Roman Instruments
=================
WARNING: This model has not yet been validated against other PSF
simulations, and uses several approximations (e.g. for
mirror polishing errors, which are taken from HST).
"""
import logging
import os.path
import pprint
from pathlib import Path
import astropy.units as u
import numpy as np
import poppy
from astropy.io import fits
from scipy.interpolate import griddata
from . import distortion, utils, stpsf_core, detectors
_log = logging.getLogger('stpsf')
GRISM_FILTERS = ('GRISM0', 'GRISM1')
PRISM_FILTERS = ('PRISM',)
class WavelengthDependenceInterpolator(object):
"""WavelengthDependenceInterpolator can be configured with
`n_zernikes` worth of Zernike coefficients at up to `n_wavelengths`
wavelengths, and will let you `get_aberration_terms` for any
wavelength in range interpolated linearly between measured/known
points
"""
def __init__(self, n_wavelengths=16, n_zernikes=22):
self._n_wavelengths = n_wavelengths
self._n_zernikes = n_zernikes
self._aberration_terms = np.zeros((n_wavelengths, n_zernikes), dtype=np.float64)
self._wavelengths = []
def set_aberration_terms(self, wavelength, zernike_array):
"""Supply a reference `wavelength` and a `zernike_array`
(of length `n_zernikes`) where the aberration is known
"""
n_wavelengths_set = len(self._wavelengths)
if wavelength not in self._wavelengths and n_wavelengths_set < self._n_wavelengths:
self._wavelengths.append(wavelength)
aberration_row_idx = n_wavelengths_set # which is now index of last row
elif wavelength in self._wavelengths:
aberration_row_idx = self._wavelengths.index(wavelength)
else:
# can't add more wavelengths without allocating new _aberration_terms array
raise ValueError(
'Already have information at {} wavelengths ' '(pass larger n_wavelengths to __init__?)'.format(
self._n_wavelengths
)
)
if len(zernike_array) != self._n_zernikes:
raise ValueError(
'Expected {} aberration terms (pass different ' 'n_zernikes to __init__?)'.format(self._n_zernikes)
)
self._aberration_terms[aberration_row_idx] = zernike_array
def get_aberration_terms(self, wavelength):
"""Return the Zernike coefficients as interpolated for this
`wavelength`"""
# return array of length n_zernikes interpolated for this wavelength
if wavelength in self._wavelengths:
# aberration known exactly for this wavelength
aberration_row_idx = self._wavelengths.index(wavelength)
return self._aberration_terms[aberration_row_idx]
else:
# we have to interpolate @ this wavelength
aberration_terms = griddata(self._wavelengths, self._aberration_terms, wavelength, method='linear')
if np.any(np.isnan(aberration_terms)):
if isinstance(wavelength, u.Quantity):
wavelength = wavelength.to(u.m).value
wavelength_closest = np.clip(wavelength, np.min(self._wavelengths), np.max(self._wavelengths))
_log.warn(
'Attempted to get aberrations at wavelength {:.2g} '
'outside the range of the reference data; clipping to closest wavelength {:.2g}'.format(
wavelength, wavelength_closest
)
)
aberration_terms = griddata(self._wavelengths, self._aberration_terms, wavelength_closest, method='linear')
return aberration_terms
class FieldDependentAberration(poppy.ZernikeWFE):
"""FieldDependentAberration incorporates aberrations that
are interpolated in wavelength, x, and y pixel positions by
computing the Zernike coefficients for a particular wavelength
and position.
"""
"""By default, `get_aberration_terms` will zero out Z1, Z2, and Z3
(piston, tip, and tilt) as they are not meaningful for telescope
PSF calculations (the former is irrelevant; the latter two would
be handled by a distortion solution). Change
`_omit_piston_tip_tilt` to False to include the Z1-3 terms."""
_omit_piston_tip_tilt = True
_field_position = None
def __init__(
self, pixel_width, pixel_height, name='Field-dependent Aberration', radius=1.0, oversample=1, interp_order=3
):
self.pixel_width, self.pixel_height = pixel_width, pixel_height
self.field_position = pixel_width // 2, pixel_height // 2
self._wavelength_interpolators = {}
self.pupil_diam = radius * 2.0
super().__init__(name=name, verbose=True, radius=radius, oversample=oversample, interp_order=interp_order)
def get_opd(self, wave):
"""Set the Zernike coefficients (for ZernikeWFE.getOPD) based
on the wavelength of the incoming wavefront and the pixel
position
"""
if not isinstance(wave, poppy.Wavefront):
wavelength = wave
else:
wavelength = wave.wavelength
self.coefficients = wavelength * self.get_aberration_terms(wavelength)
return super().get_opd(wave)
@property
def field_position(self):
return self._field_position
@field_position.setter
def field_position(self, position):
"""Set the x and y pixel position on the detector for which to
interpolate aberrations"""
x_pixel, y_pixel = position
if x_pixel > self.pixel_width or x_pixel < 0:
raise ValueError('Requested pixel_x position lies outside ' 'the detector width ({})'.format(x_pixel))
if y_pixel > self.pixel_height or y_pixel < 0:
raise ValueError('Requested pixel_y position lies outside ' 'the detector height ({})'.format(y_pixel))
self._field_position = x_pixel, y_pixel
def add_field_point(self, x_pixel, y_pixel, interpolator):
"""Supply a wavelength-space interpolator for a pixel position
on the detector"""
self._wavelength_interpolators[(x_pixel, y_pixel)] = interpolator
def get_aberration_terms(self, wavelength):
"""Supply the Zernike coefficients for the aberration based on
the wavelength and pixel position on the detector"""
if self.field_position in self._wavelength_interpolators:
# short path: this is a known point
interpolator = self._wavelength_interpolators[self.field_position]
coefficients = interpolator.get_aberration_terms(wavelength)
else:
# get aberrations at all field points
field_points, aberration_terms = [], []
for field_point_coords, point_interpolator in self._wavelength_interpolators.items():
field_points.append(field_point_coords)
aberration_terms.append(point_interpolator.get_aberration_terms(wavelength))
aberration_array = np.asarray(aberration_terms)
assert len(aberration_array.shape) == 2, (
'computed aberration array is not 2D ' '(inconsistent number of Zernike terms ' 'at each point?)'
)
field_position = tuple(self.field_position)
coefficients = griddata(np.asarray(field_points), np.asarray(aberration_terms), field_position, method='linear')
if np.any(np.isnan(coefficients)):
# FIND TWO CLOSEST INPUT GRID POINTS:
dist = []
corners = field_points[1:] # use only the corner points
for i, ip in enumerate(corners):
dist.append(np.sqrt(((ip[0] - field_position[0]) ** 2) + ((ip[1] - field_position[1]) ** 2)))
min_dist_indx = np.argsort(dist)[:2] # keep two closest points
# DEFINE LINE B/W TWO POINTS, FIND ORTHOGONAL LINE AT POINT OF INTEREST,
# AND FIND INTERSECTION OF THESE TWO LINES.
x1, y1 = corners[min_dist_indx[0]]
x2, y2 = corners[min_dist_indx[1]]
dx = x2 - x1
dy = y2 - y1
a = (dy * (field_position[1] - y1) + dx * (field_position[0] - x1)) / (dx * dx + dy * dy)
closest_interp_point = (x1 + a * dx, y1 + a * dy)
# INTERPOLATE ABERRATIONS TO CLOSEST INTERPOLATED POINT:
coefficients = griddata(
np.asarray(field_points), np.asarray(aberration_terms), closest_interp_point, method='linear'
)
# IF CLOSEST INTERPOLATED POINT IS STILL OUTSIDE THE INPUT GRID,
# THEN USE NEAREST GRID POINT INSTEAD:
if np.any(np.isnan(coefficients)):
coefficients = aberration_terms[min_dist_indx[0] + 1]
_log.warn(
'Attempted to get aberrations at field point {} which is outside the range '
'of the reference data; approximating to nearest input grid point'.format(field_position)
)
else:
_log.warn(
'Attempted to get aberrations at field point {} which is outside the range '
'of the reference data; approximating to nearest interpolated point {}'.format(
field_position, closest_interp_point
)
)
assert not np.any(np.isnan(coefficients)), 'Could not compute aberration ' 'at field point {}'.format(
field_position
)
if self._omit_piston_tip_tilt:
_log.debug('Omitting piston/tip/tilt')
coefficients[:3] = 0.0 # omit piston, tip, and tilt Zernikes
return coefficients
def _load_wfi_detector_aberrations(filename):
from astropy.io import ascii
zernike_table = ascii.read(filename, encoding='utf-8-sig')
detectors_dict = {}
def build_detector_from_table(number, zernike_table):
"""Build a FieldDependentAberration optic for a detector using
Zernikes Z1-Z45 at various wavelengths and field points"""
single_detector_info = zernike_table[zernike_table['sca'] == number]
field_points = set(single_detector_info['field_point'])
detector = FieldDependentAberration(
4096, 4096, radius=RomanInstrument.PUPIL_RADIUS,
name=f"Field Dependent Aberration (WFI{number:02d})"
)
for field_id in field_points:
field_point_rows = single_detector_info[single_detector_info['field_point'] == field_id]
local_x, local_y = field_point_rows[0]['local_x'], field_point_rows[0]['local_y']
interpolator = build_wavelength_dependence(field_point_rows)
midpoint_pixel = 4096 / 2
# (local_x in mm / 10 um pixel size) -> * 1e2
# local_x and _y range from -20.44 to +20.44, so adding to the midpoint pixel
# makes sense to place (-20.44, -20.44) at (4, 4)
pixx, pixy = (round(midpoint_pixel - local_x * 1e2), round(midpoint_pixel + local_y * 1e2))
detector.add_field_point(pixx, pixy, interpolator)
return detector
def build_wavelength_dependence(rows):
"""Build an interpolator object that interpolates Z1-Z22 in
wavelength space"""
wavelengths = set(rows['wavelength'])
interpolator = WavelengthDependenceInterpolator(n_wavelengths=len(wavelengths), n_zernikes=22)
for row in rows:
z = np.zeros(22)
for idx in range(22):
z[idx] = row['Z{}'.format(idx + 1)]
interpolator.set_aberration_terms(row['wavelength'] * 1e-6, z)
return interpolator
detector_ids = set(zernike_table['sca'])
for detid in detector_ids:
detectors_dict['WFI{:02}'.format(detid)] = build_detector_from_table(detid, zernike_table)
return detectors_dict
class _RomanInstrumentOptionsDict(dict):
"""
A wrapper for the `RomanInstrument.options` dict that prevents the
`add_distortion` key from being modified since distortion can't be added to
PSFs from Roman's WFI (whose input data is already distorted) or Coronagraph
Instrument (where distortion is not implemented).
The default value set for `add_distortion` in `RomanInstrument` should be
something other than True or False that indicates to users that distortion
can't be toggled in the Roman instrument model.
"""
def __setitem__(self, key, value):
if key == 'add_distortion' and value != 'NA':
_log.warn('Roman: add_distortion disabled for Roman PSFs')
else:
super().__setitem__(key, value)
@utils.combine_docstrings
class RomanInstrument(stpsf_core.SpaceTelescopeInstrument):
PUPIL_RADIUS = 2.4 / 2.0
"""
RomanInstrument contains data and functionality common to Roman
instruments, such as setting the pupil shape
"""
telescope = 'Roman'
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.siaf = stpsf_core.get_siaf_with_caching('roman')
self._aperturename = None
# reassign self.options from dict to _RomanInstrumentOptionsDict,
# mainly to prevent user modification of the add_distortion key
self.options['add_distortion'] = 'NA' # distortion can't be toggled
self.options = _RomanInstrumentOptionsDict(self.options.copy())
self.options['jitter'] = 'gaussian'
self.options['jitter_sigma'] = 0.012
# arcsec/axis, see https://github.com/RomanSpaceTelescope/roman-technical-information/tree/main/data/Observatory/MissionandObservatoryTechnicalOverview#telescope-parameters
def calc_psf(
self,
outfile=None,
source=None,
nlambda=None,
monochromatic=None,
fov_arcsec=None,
fov_pixels=None,
oversample=None,
detector_oversample=None,
fft_oversample=None,
overwrite=True,
display=False,
save_intermediates=False,
return_intermediates=False,
normalize='first',
add_distortion=None,
crop_psf=False,
):
"""
Compute a PSF.
Note that Roman WFI PSFs, unlike those from the JWST instruments,
always include distortion. Additionally, distortion is not implemented
in STPSF for the Roman Coronagraph Instrument. As such, the
`add_distortion` argument of the Roman implementation of `calc_psf()`
will not affect the simulated PSF.
Parameters
----------
add_distortion : None
Included for backward compatibility, but this argument has no
effect since, as mentioned above, distortion can no longer be
toggled in Roman PSFs. WFI PSFs natively include distortion effects
and RomanCoronagraph PSFs do not.
crop_psf : bool
Included for API compatibility with the JWST instrument classes,
but has no effect on the results for Roman WFI PSF calculations.
"""
if add_distortion is not None:
_log.warn('Note that the add_distortion argument no longer affects '
'Roman instrument simulations. All WFI PSFs natively '
'include distortion effects and all RomanCoronagraph '
'PSFs do not.')
# Save new keyword to the options dictionary
self.options['crop_psf'] = crop_psf
# Run poppy calc_psf
psf = stpsf_core.SpaceTelescopeInstrument.calc_psf(
self,
outfile=outfile,
source=source,
nlambda=nlambda,
monochromatic=monochromatic,
fov_arcsec=fov_arcsec,
fov_pixels=fov_pixels,
oversample=oversample,
detector_oversample=detector_oversample,
fft_oversample=fft_oversample,
overwrite=overwrite,
display=display,
save_intermediates=save_intermediates,
return_intermediates=return_intermediates,
normalize=normalize,
)
return psf
# slightly different versions of the following two functions
# from the parent superclass
# in order to interface with the FieldDependentAberration class
@property
def detector_position(self):
"""The pixel position in (X, Y) on the detector"""
return self._detectors[self._detector].field_position
@detector_position.setter
def detector_position(self, position):
# exact copy of superclass function except we save the
# into a different location.
try:
x, y = map(int, position)
except ValueError:
raise ValueError('Detector pixel coordinates must be pairs of nonnegative numbers, ' 'not {}'.format(position))
if x < 0 or y < 0:
raise ValueError('Detector pixel coordinates must be nonnegative integers')
if x > self._detector_npixels - 1 or y > self._detector_npixels - 1:
raise ValueError(
'The maximum allowed detector pixel ' 'coordinate value is {}'.format(self._detector_npixels - 1)
)
self._detectors[self._detector].field_position = (int(position[0]), int(position[1]))
def _get_aberrations(self):
"""Get the OpticalElement that applies the field-dependent
optical aberrations. (Called in get_optical_system.)"""
return self._detectors[self._detector]
def _get_fits_header(self, result, options):
"""Populate FITS Header keywords"""
super()._get_fits_header(result, options)
result[0].header['DETXPIXL'] = (self.detector_position[0], 'X pixel position (for field dependent aberrations)')
result[0].header['DETYPIXL'] = (self.detector_position[1], 'Y pixel position (for field dependent aberrations)')
result[0].header['DETECTOR'] = (self.detector, 'Detector selected')
def _calc_psf_format_output(self, result, options):
"""
Add detector charge diffusion model to the created 1-extension PSF.
(As of STPSF v2.1.0, no longer applies distortion given that WFI optical
models were delivered with inherent distortion effects in Cycle 10. If
future deliveries arrive sans distortion, see pre-v2.1.0 commit history
for code that handled distortion.)
Apply desired formatting to output file:
- rebin to detector pixel scale if desired
- set up FITS extensions if desired
- output either the oversampled, rebinned, or both
Which image(s) get output depends on the value of the options['output_mode']
parameter. It may be set to 'Oversampled image' to output just the oversampled image,
'Detector sampled image' to output just the image binned down onto detector pixels, or
'Both as FITS extensions' to output the oversampled image as primary HDU and the
rebinned image as the first image extension. For convenience, the option can be set
to just 'oversampled', 'detector', or 'both'.
Modifies the 'result' HDUList object.
"""
# Set up new extensions for detector charge transfer model
n_exts = len(result)
for ext in np.arange(n_exts):
hdu_new = fits.ImageHDU(result[ext].data, result[ext].header)
# ^ these will be the PSFs that are edited ^
result.append(hdu_new)
ext_new = ext + n_exts
result[ext_new].header['EXTNAME'] = result[ext].header['EXTNAME'][0:4] + 'DIST' # change extension name
_log.debug('Appending new extension {} with EXTNAME = {}'.format(ext_new, result[ext_new].header['EXTNAME']))
# apply detector charge transfer model
psf_updated = detectors.apply_detector_charge_diffusion(result,
options)
# Edit the variable to match if input didn't request distortion
# (cannot set result = psf_updated due to return method)
[result.append(fits.ImageHDU()) for i in np.arange(len(psf_updated) - len(result))]
for ext in np.arange(len(psf_updated)):
result[ext] = psf_updated[ext]
# Rewrite result variable based on output_mode set:
stpsf_core.SpaceTelescopeInstrument._calc_psf_format_output(self, result, options)
class WFIPupilController:
"""
This is a helper class for the WFI and is used to swap in
the correct pupil each time the detector is changed.
The pupil depends on pupil_mask, detector, and filter;
pupil_mask is set automatically upon the receipt of the
detector and filter values selected by the user in the WFI class.
Users should only interact with this class through the API provided
in the WFI class.
Parameters
----------
datapath : string
Path to STPSF-WFI data files
"""
def __init__(self, datapath):
self.set_base_path(datapath)
self._pupil = None
self._pupil_mask = None
# Flag to en-/disable automatic selection of the appropriate pupil_mask
self._auto_pupil = True
# Flag to en-/disable automatic selection of the appropriate pupil file
self._auto_pupil_mask = True
@property
def pupil(self):
"""
The path to the FITS file containing pupil information for the
detector/filter combination sent from the WFI class. Cannot be
directly set by the user.
"""
return self._pupil
@pupil.setter
def pupil(self, value):
raise AttributeError('Pupil cannot be directly specified. ' 'Use lock_pupil() instead.')
@property
def pupil_mask(self):
"""
The corresponding mask for the filter sent from the WFI class.
(See WFI.pupil_mask_list for a list of valid filters.) Cannot
be directly set by the user.
"""
return self._pupil_mask
@pupil_mask.setter
def pupil_mask(self, name):
raise AttributeError('Pupil mask cannot be directly specified. '
'Use lock_pupil_mask() instead.')
def _get_pupil_mask(self, wfi_filter):
"""
Returns the appropriate pupil mask for a given WFI filter.
Parameters
----------
wfi_filter : string
See WFI.filter_list for a list of valid filters.
"""
wfi_filter = wfi_filter.upper()
if wfi_filter in GRISM_FILTERS:
# As of Cycle 10, GRISM0 and GRISM1 are the only filters that share
# a set of pupil masks with each other
return 'GRISM'
else:
return wfi_filter
def set_base_path(self, datapath):
"""
Sets the root directory of the path to STPSF's data files.
This should be set before this class is used.
Parameters
----------
datapath : string
Path to STPSF-WFI data files
"""
self._datapath = datapath
self._pupil_basepath = os.path.join(self._datapath, 'pupils')
def pupil_file_formatter(self, wfi_filter, detector):
"""
Generate proper pupil filename given a filter and a detector.
Parameters
----------
wfi_filter : string
See WFI.filter_list for a list of valid filters.
detector : string
See WFI.detector_list for a list of valid detectors.
"""
if wfi_filter.upper().startswith('F'):
return f"RST_WIM_Filter_{wfi_filter}_{detector}.fits.gz"
elif wfi_filter.upper().startswith('GRISM'):
return f"RST_WSM_Grism_grism_{detector}.fits.gz"
elif wfi_filter.upper() == 'PRISM':
return f"RST_WSM_Prism_prism_{detector}.fits.gz"
def update_pupil(self, wfi_filter, detector):
"""
Selects the specific pupil file corresponding with a detector
and filter combination sent from the WFI class. Also finds and
indirectly sets the proper pupil_mask in the process.
Parameters
----------
wfi_filter : string
See WFI.filter_list for a list of valid filters.
detector : string
See WFI.detector_list for a list of valid detectors.
"""
if not self._auto_pupil:
_log.info('Automatic pupil selection was locked; '
'using user-provided pupil.')
return
if self._pupil_basepath is None:
raise Exception('update_pupil called before setting pupil file path')
# figure out proper mask based on filter (or use locked mask if enabled)
pupil_mask = self._get_pupil_mask(wfi_filter) if self._auto_pupil_mask else self.pupil_mask
pupil = os.path.join(self._pupil_basepath,
self.pupil_file_formatter(pupil_mask, detector))
self._pupil_mask = pupil_mask
self._pupil = pupil
_log.info(
f"Using {'' if self._auto_pupil_mask else 'locked '}"
f"pupil mask '{pupil_mask}' and detector '{detector}'."
)
def lock_pupil(self, pupil_path):
"""
Prevents the WFIPupilController class from dynamically updating
the path to the pupil on any changes to the detector or filter
selected in the WFI class. Instead, the path remains locked on
whichever `pupil_path` was provided to this method.
CAUTION: This is non-standard usage of the WFI class and may
lead to unexpected behavior.
Parameters
----------
pupil_path : string
The custom path to your pupil file.
"""
self._pupil_mask = None
self._pupil = pupil_path
self._auto_pupil = False
def unlock_pupil(self):
"""
Undoes the effects of lock_pupil() and resets WFIPupilController
to its default state of updating the pupil whenever a detector
or filter is changed in the WFI class.
"""
self._auto_pupil = True
def lock_pupil_mask(self, pupil_mask):
"""
Prevents the WFIPupilController class from dynamically updating
the pupil mask on any changes to the filter selected in the WFI
class. Instead, the pupil mask remains locked on whichever
`pupil_mask` was provided to this method.
CAUTION: This is non-standard usage of the WFI class and may
lead to unexpected behavior.
Parameters
----------
filter : string
See WFI.pupil_mask_list for a list of valid pupil masks.
"""
if not self._auto_pupil:
raise Exception('Pupil is locked. Unlock pupil before locking pupil mask.')
else:
self._pupil_mask = pupil_mask
self._auto_pupil_mask = False
def unlock_pupil_mask(self):
"""
Undoes the effects of lock_pupil_mask() and resets
WFIPupilController to its default state of updating the pupil
mask whenever filter is changed in the WFI class.
"""
self._auto_pupil_mask = True
[docs]
class WFI(RomanInstrument):
"""
WFI represents the Roman mission's Wide Field Imager.
WARNING: This model has not yet been validated against other PSF
simulations, and uses several approximations (e.g. for
mirror polishing errors, which are taken from HST).
"""
def __init__(self):
# pixel scale is from Roman-AFTA SDT report final version (p. 91)
# https://roman.ipac.caltech.edu/sims/Param_db.html
pixelscale = 110e-3 # arcsec/px
# Initialize the aberrations for parent SpaceTelescopeInstrument class
self._aberration_files = {}
self._is_custom_aberration = False
self._current_aberration_file = ''
super().__init__('WFI', pixelscale=pixelscale)
# Initialize the pupil controller
self._pupil_controller = WFIPupilController(self._datapath)
self.pupil_mask_list = [fltr for fltr in self.filter_list.copy()
if not fltr.startswith('GRISM')]
self.pupil_mask_list.append(np.str_('GRISM')) # GRISM0/1 share pupils
# Define default aberration files for WFI filters
self._aberration_files = {'custom': None}
self._aberration_files.update({
fltr: os.path.join(
self._datapath,
(f"{'WIM' if fltr.startswith('F') else 'WSM'}"
f"_{fltr}_zernikes_cycle10.csv"))
for fltr in self.filter_list
})
# Load and set default detector from aberration file
self._detector_npixels = 4096
self._load_detector_aberrations(self._aberration_files[self.mode])
self.detector = 'WFI01'
self.opd_list = [os.path.join(self._STPSF_basepath, 'upscaled_HST_OPD.fits')]
self.pupilopd = self.opd_list[-1]
def _addAdditionalOptics(self, optsys, **kwargs):
_log.debug(' No optics added for WFI')
return optsys, False, None
def _load_detector_aberrations(self, path):
"""
Helper function that, given a path to a file containing detector
aberrations, loads the Zernike values and populates the class'
dictator list with `FieldDependentAberration` detectors. This
function achieves this by calling the
`stpsf.roman._load_wfi_detector_aberrations` function.
Users should use the `override_aberrations` function to override
current aberrations.
Parameters
----------
path : string
The path to the file containing detector aberrations.
"""
detectors_dict = _load_wfi_detector_aberrations(path)
assert len(detectors_dict.keys()) > 0
self._detectors = detectors_dict
self._current_aberration_file = path
def _validate_config(self, **kwargs):
"""
Validates that the WFI is configured sensibly.
This mainly consists of selecting the masked or unmasked pupil
appropriately based on the wavelengths requested.
"""
assert self.filter is not None, 'filter is None'
assert self.detector is not None, 'detector is None'
self._update_pupil()
assert self.pupil is not None, 'pupil is None'
super()._validate_config(**kwargs)
def _update_pupil(self, wfi_filter=None, detector=None):
if detector is None:
detector = self.detector
if wfi_filter is None:
wfi_filter = self.filter
if detector is not None and wfi_filter is not None:
self._pupil_controller.update_pupil(wfi_filter=wfi_filter,
detector=detector)
@RomanInstrument.detector.setter
def detector(self, value):
"""
The current WFI detector. See WFI.detector_list for valid values.
As of Cycle 10, also switches the current filter's throughput file
location since these are now detector-based.
"""
if value.upper().startswith('SCA'): # backward-compatible name assignment
value = f"WFI{value[-2:]}"
if value.upper() not in self.detector_list:
raise ValueError('Invalid detector. Valid detector names are: {}'.format(', '.join(self.detector_list)))
self._detector = value.upper()
if self._detector is not None:
self._update_pupil(detector=self._detector)
self._update_aperturename()
def _update_aperturename(self):
"""Update SIAF aperture name after change in detector or other relevant properties.
This function handles just inferring the new value of the aperturename.
See the aperturename.setter function for additional changed based on that.
"""
self.aperturename = self._detector.replace('SCA', 'WFI') + "_FULL"
@RomanInstrument.aperturename.setter
def aperturename(self, value):
"""Set SIAF aperture name to new value, with validation.
This also updates the pixelscale to the local value for that aperture, for a small precision enhancement.
"""
try:
ap = self.siaf[value]
except KeyError:
raise ValueError(f'Aperture name {value} not a valid SIAF aperture name for {self.name}')
# Only update if new value is different
if self._aperturename != value:
self._aperturename = value
# Update pixelscale based on specified aperture name
self.pixelscale = self._get_pixelscale_from_apername(value)
# adjust filter throughput file location
found_parent = False
filters_info = {}
for fl, info in self._filters.items():
filter_path = Path(info.filename)
# find 'filters', the earliest common parent directory of default
# stpsf filter file structure (stpsf-data/INSTRUMENT/*filters*)
# and WFI's filter file structure (stpsf-data/WFI/*filters*/DETECTOR).
if not found_parent:
for parent in filter_path.parents:
if parent.name == 'filters':
found_parent = True
break
else:
continue
# done this way because SpaceTelescopeInstrument.__init__()
# (a WFI parent class) sets filter location to the default WFI path
# with SpaceTelescopeInstrument._get_filters() upon class creation,
# so the filter files' direct parent directory the first time a
# detector is assigned in WFI.__init__() (the "filters" directory)
# is not at the same level as on later changes to the detector attribute
# (the corresponding "WFINN" child directory of "WFI/filters").
# save filter info but change throughput file based on new detector
info_edit = {key : (val if key != 'filename'
else str(parent / self._detector / filter_path.name))
for key, val in info._asdict().items()}
filters_info[fl] = stpsf_core.Filter(**info_edit)
self._filters = filters_info
@RomanInstrument.filter.setter
def filter(self, value):
"""
The current WFI filter. See WFI.filter_list for valid values.
"""
# Update filter
value = value.upper()
if value not in self.filter_list:
raise ValueError(f"Instrument {self.name} doesn't have a "
f"filter called {value}.")
self._filter = value
# Update aberrations if self._aberration_files has been initiated (not
# empty) and if they haven't been locked by user
if self._aberration_files and not self._is_custom_aberration:
# identify aberration file for new mode
aberration_file = self._aberration_files[self._filter]
# if aberrations are not already loaded for the new mode,
# load and replace detectors using the new mode's aberration file
if not os.path.samefile(self._current_aberration_file, aberration_file):
self._load_detector_aberrations(aberration_file)
# Update pupil only if detector was previously loaded
# ( i.e., skip this step when called by super() )
if self.detector is not None:
self._update_pupil(wfi_filter=self._filter)
@property
def pupil(self):
"""
The path to the FITS file containing pupil information for the
detector/filter combination sent from the WFI class. Cannot be
directly set by the user.
"""
return self._pupil_controller.pupil
@pupil.setter
def pupil(self, value):
# don't allow pupil to be set until the pupil controller is active. (a
# parent class tries to set it to None in WFI's preceding super() call)
if hasattr(self, '_pupil_controller'):
raise AttributeError('Pupil cannot be directly specified. ' 'Use lock_pupil() instead.')
@property
def pupil_mask(self):
"""
The corresponding mask for the current filter. Cannot be
directly set by the user.
"""
return self._pupil_controller.pupil_mask
@pupil_mask.setter
def pupil_mask(self, name):
raise AttributeError('Pupil mask cannot be directly specified. ' 'Use lock_pupil_mask() instead.')
@property
def mode(self):
"""
The current WFI mode. Cannot be directly set by the user.
"""
return self.filter
@mode.setter
def mode(self, value):
raise AttributeError('WFI mode cannot be directly specified; ' 'it is set by changing filters.')
[docs]
def lock_aberrations(self, aberration_path):
"""
This function loads user provided aberrations from a file and
locks this instrument to only use the provided aberrations (even
if the filter or mode change).
To release the lock and load the default aberrations, use
unlock_aberrations(). To load new user provided
aberrations, call this function with the new path.
To load custom aberrations, please provide a csv file
containing the detector names, field point positions and Zernike
values. The file should contain the following column
names/values (comments in parentheses should not be included):
- sca (Detector number)
- wavelength (µm)
- field_point (field point number/ID for detector and wavelength.
starts with 1)
- local_x (mm, local detector coords)
- local_y (mm, local detector coords)
- global_x (mm, global instrument coords)
- global_y (mm, global instrument coords)
- axis_local_angle_x (XAN)
- axis_local_angle_y (YAN)
- wfe_rms_waves (nm)
- wfe_pv_waves (waves)
- Z1 (Zernike phase NOLL coefficients)
- Z2 (Zernike phase NOLL coefficients)
- Z3 (Zernike phase NOLL coefficients)
- Z4 (Zernike phase NOLL coefficients)
- ...
Please refer to the default aberration files for examples. If
you have the STPSF data installed and defined, you can get the
path to that file by running the following:
>>> from stpsf import roman
>>> wfi = roman.WFI()
>>> print(wfi._aberration_files['imaging'])
Warning: You should not edit the default files!
"""
self._load_detector_aberrations(aberration_path)
self._aberration_files['custom'] = aberration_path
self._is_custom_aberration = True
[docs]
def unlock_aberrations(self):
"""
Releases the lock on the detector aberration file location
and loads the default file.
"""
aberration_path = self._aberration_files[self.mode]
self._load_detector_aberrations(aberration_path)
self._aberration_files['custom'] = None
self._is_custom_aberration = False
[docs]
def lock_pupil(self, pupil_path):
"""
Prevents dynamic updates of the path to the proper pupil file on
any changes to the selected detector or filter. Instead, the
path remains locked on whichever `pupil_path` was provided here.
WARNING: This is non-standard usage of the WFI class and may
lead to unexpected behavior.
Parameters
----------
pupil_path : string
The custom path to your pupil file.
"""
if os.path.isfile(pupil_path):
self._pupil_controller.lock_pupil(pupil_path)
else:
raise FileNotFoundError(f'{pupil_path} not found.')
_log.warning('Disabling default pupil selection behavior.')
[docs]
def unlock_pupil(self):
"""
Undoes the effects of lock_pupil() by resetting the class to
its default state of updating the pupil whenever a detector or
filter is changed. If necessary, it also sets the proper pupil
for the current detector/filter combination.
"""
self._pupil_controller.unlock_pupil()
self._update_pupil() # reset pupil
_log.info('Restoring default pupil selection behavior.')
[docs]
def lock_pupil_mask(self, pupil_mask):
"""
Prevents dynamic updates of the pupil mask on any change to the
selected filter. Instead, the pupil mask remains locked on
whichever `pupil_mask` was provided here.
WARNING: This is non-standard usage of the WFI class and may
lead to unexpected behavior.
Parameters
----------
filter : string
See WFI.pupil_mask_list for a list of valid pupil masks.
"""
if pupil_mask not in self.pupil_mask_list:
raise Exception('invalid pupil mask')
self._pupil_controller.lock_pupil_mask(pupil_mask)
self._update_pupil()
_log.warning('Disabling default pupil mask selection behavior.')
[docs]
def unlock_pupil_mask(self):
"""
Undoes the effects of lock_pupil_mask() and resets the class to
its default state of updating the pupil mask whenever the filter
is changed.
"""
self._pupil_controller.unlock_pupil_mask()
self._update_pupil() # reset pupil mask
_log.info('Restoring default pupil mask selection behavior.')
[docs]
class RomanCoronagraph(RomanInstrument):
"""
Roman Coronagraph Instrument
Simulates the PSF of the Roman coronagraph.
Current functionality is limited to the Shaped Pupil Coronagraph (SPC)
observing modes, and these modes are only simulated with static, unaberrated
wavefronts, without relay optics and without DM control. The design
represented here is an approximation to a baseline concept, and will be
subject to change based on trades studies and technology development.
Parameters
----------
mode : str
Roman Coronagraph Instrument observing mode. If not specified, the
__init__ function will set this to a default mode 'CHARSPC_F660'
pixelscale : float
Detector pixelscale. If not specified, the pixelscale will default to
0.02 arcsec for configurations usint the IMAGER camera and 0.025 arcsec
for the IFS.
fov_arcsec : float
Field of view in arcseconds. If not specified, the field of view will
default to 3.20 arcsec for the IMAGER camera and 1.76 arcsec for the IFS.
"""
camera_list = ['IMAGER', 'IFS']
filter_list = ['F660', 'F721', 'F770', 'F890']
apodizer_list = ['CHARSPC', 'DISKSPC']
fpm_list = ['CHARSPC_F660_BOWTIE', 'CHARSPC_F770_BOWTIE', 'CHARSPC_F890_BOWTIE', 'DISKSPC_F721_ANNULUS']
lyotstop_list = ['LS30D88']
_mode_table = { # MODE CAMERA FILTER APODIZER FPM LYOT STOP
'CHARSPC_F660': ('IFS', 'F660', 'CHARSPC', 'CHARSPC_F660_BOWTIE', 'LS30D88'),
'CHARSPC_F770': ('IFS', 'F770', 'CHARSPC', 'CHARSPC_F770_BOWTIE', 'LS30D88'),
'CHARSPC_F890': ('IFS', 'F890', 'CHARSPC', 'CHARSPC_F890_BOWTIE', 'LS30D88'),
'DISKSPC_F721': ('IMAGER', 'F721', 'DISKSPC', 'DISKSPC_F721_ANNULUS', 'LS30D88'),
}
def __init__(self, mode=None, pixelscale=None, fov_arcsec=None, apply_static_opd=False):
super().__init__('RomanCoronagraph', pixelscale=pixelscale)
self._detector_npixels = 1024
self._detectors = {camera: 'placeholder' for camera in self.camera_list}
self.pupil_mask_list = self.lyotstop_list # alias for use in stpsf_core
self.image_mask_list = self.fpm_list # alias for use in stpsf_core
self.pupil = os.path.join(self._STPSF_basepath, 'AFTA_CGI_C5_Pupil_onax_256px_flip.fits')
if apply_static_opd:
self.pupilopd = os.path.join(self._STPSF_basepath, 'CGI', 'OPD', 'CGI_static_OPD.fits')
else:
self.pupilopd = None
self.aberration_optic = None
self.options = {'force_coron': True}
# Allow the user to preemptively override the default instrument FoV and pixel scale
if fov_arcsec is not None:
self.fov_arcsec = fov_arcsec
self._override_fov = True
else:
self._override_fov = False
if pixelscale is not None:
self._pixelscale = pixelscale
self._override_pixelscale = True
else:
self._override_pixelscale = False
if mode is None:
self.print_mode_table()
_log.info('Since the mode was not specified at instantiation, defaulting to CHARSPC_F660')
self.mode = 'CHARSPC_F660'
else:
self.mode = mode
@property
def camera(self):
"""Currently selected camera name"""
return self._camera
@camera.setter
def camera(self, value):
value = value.upper() # force to uppercase
if value not in self.camera_list:
raise ValueError("Instrument {0} doesn't have a camera called {1}.".format(self.name, value))
self._camera = value
if value == 'IMAGER':
if not hasattr(self, 'fov_arcsec') or not self._override_fov:
self.fov_arcsec = 3.2
if not hasattr(self, 'pixelscale') or not self._override_pixelscale:
self.pixelscale = 0.020 # Nyquist at 465 nm
else: # default to 'IFS'
if not hasattr(self, 'fov_arcsec') or not self._override_fov:
self.fov_arcsec = 2 * 0.82 # 2015 SDT report, Section 3.4.1.1.1:
# IFS has 76 lenslets across the (2 x 0.82) arcsec FoV.
if not hasattr(self, 'pixelscale') or not self._override_pixelscale:
self.pixelscale = 0.025 # Nyquist at 600 nm
# for coronagraph, there is one detector per camera and it should be set automatically.
@property
def detector(self):
return self.camera
@detector.setter
def detector(self, value):
raise RuntimeError("Can't set detector directly for RomanCoronagraph; set camera instead.")
@property
def filter(self):
"""Currently selected filter name"""
return self._filter
@filter.setter
def filter(self, value):
value = value.upper() # force to uppercase
if value not in self.filter_list:
raise ValueError("Instrument {0} doesn't have a filter called {1}.".format(self.name, value))
self._filter = value
@property
def apodizer(self):
"""Currently selected apodizer name"""
return self._apodizer
@apodizer.setter
def apodizer(self, value):
value = value.upper() # force to uppercase
if value not in self.apodizer_list:
raise ValueError("Instrument {0} doesn't have a apodizer called {1}.".format(self.name, value))
self._apodizer = value
if value == 'DISKSPC':
self._apodizer_fname = os.path.join(self._datapath, 'optics/DISKSPC_SP_256pix.fits.gz')
else: # for now, default to CHARSPC
self._apodizer_fname = os.path.join(self._datapath, 'optics/CHARSPC_SP_256pix.fits.gz')
@property
def fpm(self):
"""Currently selected FPM name"""
return self._fpm
@fpm.setter
def fpm(self, value):
value = value.upper() # force to uppercase
if value not in self.fpm_list:
raise ValueError("Instrument {0} doesn't have a FPM called {1}.".format(self.name, value))
self._fpm = value
if value.startswith('DISKSPC'):
self._fpmres = 3
self._owa = 20.0
self._Mfpm = int(np.ceil(self._fpmres * self._owa))
self._fpm_fname = os.path.join(
self._datapath,
'optics/DISKSPC_FPM_65WA200_360deg_-_FP1res{0:d}_evensamp_D{1:03d}_{2:s}.fits.gz'.format(
self._fpmres, 2 * self._Mfpm, self.filter
),
)
else:
self._fpmres = 4
self._owa = 9.0
self._Mfpm = int(np.ceil(self._fpmres * self._owa))
self._fpm_fname = os.path.join(
self._datapath,
'optics/CHARSPC_FPM_25WA90_2x65deg_-_FP1res{0:d}_evensamp_D{1:03d}_{2:s}.fits.gz'.format(
self._fpmres, 2 * self._Mfpm, self.filter
),
)
@property
def lyotstop(self):
"""Currently selected Lyot stop name"""
return self._lyotstop
@lyotstop.setter
def lyotstop(self, value):
# preserve case for this one since we're used to that with the lyot mask names
if value not in self.lyotstop_list:
raise ValueError("Instrument {0} doesn't have a Lyot mask called {1}.".format(self.name, value))
self._lyotstop = value
self._lyotstop_fname = os.path.join(self._datapath, 'optics/SPC_LS_30D88_256pix.fits.gz')
@property
def mode_list(self):
"""Available Observation Modes"""
keys = self._mode_table.keys()
keys = sorted(keys)
return keys
# mode works differently since it's a meta-property that affects the other ones:
@property
def mode(self):
"""Currently selected mode name"""
for modename, settings in self._mode_table.items():
if (
self.camera == settings[0].upper()
and self.filter == settings[1].upper()
and self.apodizer == settings[2].upper()
and self.fpm == settings[3].upper()
and self.lyotstop == settings[4]
):
return modename
return 'Custom'
@mode.setter
def mode(self, value):
if value not in self.mode_list:
raise ValueError("Instrument {0} doesn't have a mode called {1}.".format(self.name, value))
settings = self._mode_table[value]
self.camera = settings[0]
self.filter = settings[1]
self.apodizer = settings[2]
self.fpm = settings[3]
self.lyotstop = settings[4]
_log.info('Set the following optical configuration:')
_log.info(
'camera = {0}, filter = {1}, apodizer = {2}, fpm = {3}, lyotstop = {4}'.format(
self.camera, self.filter, self.apodizer, self.fpm, self.lyotstop
)
)
[docs]
def print_mode_table(self):
"""Print the table of observing mode options and their associated optical configuration"""
_log.info('Printing the table of Roman Coronagraph Instrument observing modes supported by STPSF.')
_log.info(
'Each is defined by a combo of camera, filter, apodizer, '
'focal plane mask (FPM), and Lyot stop settings:'
)
_log.info(pprint.pformat(self._mode_table))
@property
def detector_position(self):
"""The pixel position in (X, Y) on the detector"""
return 512, 512
@detector_position.setter
def detector_position(self, position):
raise RuntimeError('Detector position not adjustable for RomanCoronagraph')
def _validate_config(self, **kwargs):
super()._validate_config(**kwargs)
def _addAdditionalOptics(self, optsys, oversample=4):
"""Add coronagraphic or spectrographic optics for RomanCoronagraph."""
trySAM = False
if ('pupil_shift_x' in self.options and self.options['pupil_shift_x'] != 0) or (
'pupil_shift_y' in self.options and self.options['pupil_shift_y'] != 0
):
shift = (self.options['pupil_shift_x'], self.options['pupil_shift_y'])
else:
shift = None
# Add the shaped pupil apodizer
optsys.add_pupil(transmission=self._apodizer_fname, name=self.apodizer, shift=None)
# Add the FPM
optsys.add_image(transmission=self._fpm_fname, name=self.fpm)
# Add Lyot stop
self.pupil_mask = self.lyotstop
optsys.add_pupil(transmission=self._lyotstop_fname, name=self.lyotstop, shift=shift)
# Cast as MatrixFTCoronagraph; this configures the detector
occ_box_size = 1.0
mft_optsys = poppy.MatrixFTCoronagraph(optsys, oversample=oversample, occulter_box=occ_box_size)
return mft_optsys, trySAM, occ_box_size
def _get_aberrations(self):
"""Get the OpticalElement that applies the field-dependent
optical aberrations. (Called in get_optical_system.)"""
return None
def _get_fits_header(self, result, options):
"""Populate FITS Header keywords"""
super()._get_fits_header(result, options)
apodizer_hdr = fits.getheader(self._apodizer_fname)
fpm_hdr = fits.getheader(self._fpm_fname)
lyotstop_hdr = fits.getheader(self._lyotstop_fname)
result[0].header.set('MODE', self.mode, comment='Observing mode')
result[0].header.set('CAMERA', self.camera, comment='Imager or IFS')
result[0].header.set('APODIZER', self.apodizer, comment='Apodizer')
result[0].header.set('APODTRAN', os.path.basename(self._apodizer_fname), comment='Apodizer transmission')
result[0].header.set('PUPLSCAL', apodizer_hdr['PUPLSCAL'], comment='Apodizer pixel scale in m/pixel')
result[0].header.set('PUPLDIAM', apodizer_hdr['PUPLDIAM'], comment='Full apodizer array size, incl padding.')
result[0].header.set('FPM', self.fpm, comment='Focal plane mask')
result[0].header.set('FPMTRAN', os.path.basename(self._fpm_fname), comment='FPM transmission')
result[0].header.set('FPMSCAL', fpm_hdr['PIXSCALE'], comment='FPM spatial sampling, arcsec/pix')
result[0].header.set('LYOTSTOP', self.lyotstop, comment='Lyot stop')
result[0].header.set('LSTRAN', os.path.basename(self._lyotstop_fname), comment='Lyot stop transmission')
result[0].header.set('PUPLSCAL', lyotstop_hdr['PUPLSCAL'], comment='Lyot stop pixel scale in m/pixel')
result[0].header.set('PUPLDIAM', lyotstop_hdr['PUPLDIAM'], comment='Lyot stop array size, incl padding.')