pynrc.NIRCam¶

NIRCam base instrument class

Creates a NIRCam instrument class that holds all the information pertinent to an observation using a given observation. This class extends the NIRCam subclass webbpsf_ext.NIRCam_ext, to generate PSF coefficients to calculate an arbitrary PSF based on wavelength, field position, and WFE drift.

In addition to PSF generation, includes ability to estimate detector saturation limits, sensitivities, and perform ramp optimizations.

Parameters

filter (str) – Name of input filter.
pupil_mask (str, None) – Pupil elements such as grisms or lyot stops (default: None).
image_mask (str, None) – Specify which coronagraphic occulter (default: None).
ND_acq (bool) – Add in neutral density attenuation in throughput and PSF creation? Used primarily for sensitivity and saturation calculations. Not recommended for simulations (TBI).
detector (int or str) – NRC[A-B][1-5] or 481-490
apname (str) – Pass specific SIAF aperture name, which will update pupil mask, image mask, and detector subarray information.
autogen_coeffs (bool) – Automatically generate base PSF coefficients. Equivalent to performing self.gen_psf_coeff(). Default: True WFE drift and field-dependent coefficients should be run manually via gen_wfedrift_coeff, gen_wfefield_coeff, and gen_wfemask_coeff.

keyword wind_mode

Window mode type ‘FULL’, ‘STRIPE’, ‘WINDOW’.

kwtype wind_mode

str

keyword xpix

Size of window in x-pixels for frame time calculation.

kwtype xpix

int

keyword ypix

Size of window in y-pixels for frame time calculation.

kwtype ypix

int

keyword x0

Lower-left x-coord position of detector window.

kwtype x0

int

keyword y0

Lower-left y-coord position of detector window.

kwtype y0

int

keyword read_mode

NIRCam Ramp Readout mode such as ‘RAPID’, ‘BRIGHT1’, etc.

kwtype read_mode

str

keyword nint

Number of integrations (ramps).

kwtype nint

int

keyword ngroup

Number of groups in a integration.

kwtype ngroup

int

keyword nf

Number of frames per group.

kwtype nf

int

keyword nd1

Number of drop frame after reset (before first group read).

kwtype nd1

int

keyword nd2

Number of drop frames within a group (ie., groupgap).

kwtype nd2

int

keyword nd3

Number of drop frames after final read frame in ramp.

kwtype nd3

int

keyword nr1

Number of reset frames within first ramp.

kwtype nr1

int

keyword nr2

Number of reset frames for subsequent ramps.

kwtype nr2

int

keyword PSF Keywords

keyword ============

keyword fov_pix

Size of the PSF FoV in pixels (real SW or LW pixels). The defaults depend on the type of observation. Odd number place the PSF on the center of the pixel, whereas an even number centers it on the “crosshairs.”

kwtype fov_pix

int

keyword oversample

Factor to oversample during WebbPSF calculations. Default 2 for coronagraphy and 4 otherwise.

kwtype oversample

int

keyword include_si_wfe

Include SI WFE measurements? Default=True.

kwtype include_si_wfe

bool

keyword include_distortions

If True, will include a distorted version of the PSF.

kwtype include_distortions

bool

keyword pupil

File name or HDUList specifying telescope entrance pupil. Can also be an OTE_Linear_Model.

kwtype pupil

str

keyword pupilopd

Tuple (file, index) or filename or HDUList specifying OPD. Can also be an OTE_Linear_Model.

kwtype pupilopd

tuple or HDUList

keyword wfe_drift

Wavefront error drift amplitude in nm.

kwtype wfe_drift

float

keyword offset_r

Radial offset from the center in arcsec.

kwtype offset_r

float

keyword offset_theta

Position angle for radial offset, in degrees CCW.

kwtype offset_theta

float

keyword bar_offset

For wedge masks, option to set the PSF position across the bar.

kwtype bar_offset

float

keyword jitter

Currently either ‘gaussian’ or None.

kwtype jitter

str or None

keyword jitter_sigma

If jitter = 'gaussian', then this is the size of the blurring effect.

kwtype jitter_sigma

float

keyword npsf

Number of wavelengths/PSFs to fit.

kwtype npsf

int

keyword ndeg

Degree of polynomial fit.

kwtype ndeg

int

keyword nproc

Manual setting of number of processor cores to break up PSF calculation. If set to None, this is determined based on the requested PSF size, number of available memory, and hardware processor cores. The automatic calculation endeavors to leave a number of resources available to the user so as to not crash the user’s machine.

kwtype nproc

int

keyword save

Save the resulting PSF coefficients to a file? (default: True)

kwtype save

bool

keyword force

Forces a recalculation of PSF even if saved PSF exists. (default: False)

kwtype force

bool

keyword quick

Only perform a fit over the filter bandpass with a lower default polynomial degree fit. (default: True)

kwtype quick

bool

keyword use_legendre

Fit with Legendre polynomials, an orthonormal basis set. (default: True)

kwtype use_legendre

bool

Module Attributes

`LONG_WAVELENGTH_MAX`
`LONG_WAVELENGTH_MIN`
`ND_acq`	Use Coronagraphic ND acquisition square?
`SHORT_WAVELENGTH_MAX`
`SHORT_WAVELENGTH_MIN`
`aperturename`	SIAF aperture name for detector pixel to sky coords transformations
`bandpass`	Return bandpass throughput
`channel`
`coron_substrate`	Include coronagraphic substrate material?
`det_info`	Dictionary housing detector info parameters and keywords.
`detector`	Detector selected for simulated PSF
`detector_list`	Detectors on which the simulated PSF could lie
`detector_position`	The pixel position in (X, Y) on the detector, relative to the currently-selected SIAF aperture subarray.
`fastaxis`	Fast readout direction in sci coords
`filter`	Currently selected filter name (e.g.
`filter_list`	List of available filter names for this instrument
`fov_pix`
`image_mask`	Currently selected image plane mask, or None for direct imaging
`is_coron`	Observation with coronagraphic mask (incl Lyot stop)?
`is_dark`
`is_grism`
`is_lyot`	Is a Lyot mask in the pupil wheel?
`module`
`multiaccum`	`multiaccum` object
`multiaccum_times`	Exposure timings in dictionary
`name`
`ndeg`
`npsf`	Number of wavelengths/PSFs to fit
`options`	A dictionary capable of storing other arbitrary options, for extensibility.
`oversample`
`pixelscale`	Detector pixel scale, in arcsec/pixel
`psf_info`	PSF parameters
`pupil`	Filename or fits.HDUList for JWST pupil mask.
`pupil_mask`	Currently selected Lyot pupil mask, or None for direct imaging
`pupilopd`	Filename or fits.HDUList for JWST pupil OPD.
`quick`	Perform quicker coeff calculation over limited bandwidth?
`save_dir`	Coefficient save directory
`save_name`	Coefficient file name
`scaid`	SCA ID (481, 482, .
`siaf_ap`	SIAF Aperture object
`siaf_ap_names`	Give all possible SIAF aperture names
`slowaxis`	Slow readout direction in sci coords
`telescope`
`wave_fit`	Wavelength range to fit
`well_level`	Detector well level in units of electrons