EffectiveApertureInstrument¶

class nyx.instrument.effective_aperture.EffectiveApertureInstrument[source]¶

Bases: InstrumentModel

An instrument whose pixels have a centre, a throughput weight and a bandpass.

The response is a fixed table on a shared PixelLattice, as produced by an iactrace ray-tracing scan. Build one with from_iactrace_table() from a saved scan, or from_iactrace() to scan from scratch.

Trainable in efficiency, pixel_efficiency, shift and rotation, the last two per observation, and in misalignment_lon and misalignment_lat when that option is switched on. The forward model uses efficiency * pixel_efficiency[i], so the first two are degenerate: freeze one before fitting for a unique MLE.

Build the instrument.

Parameters:

geo (Geometry)
bandpass (callable) – Maps a wavelength Quantity to transmission.
grid (array-like, shape (n_pixels, 2, grid_dim), or PixelLattice) – Pixel sub-grid coordinates in radians, from which the shared response lattice is recovered; or that lattice directly.
values (array-like, shape (n_pixels, grid_dim, grid_dim)) – Pixel response at the sub-grid points, of the aligned optics.
misalignment (float, pair of floats, or None) – Initial facet tilt RMS in arcseconds, one value or one per axis as [lon, lat]. None means no misalignment.

Attributes Summary

`bandpass`	Spectral transmission curve, shape `(n_wvl,)`, excluding efficiency.
`bandpass_values`
`blur`	Misalignment blur width in lattice nodes, `[lon, lat]`, or `None`.
`centers`	Pixel centres in the offset frame, shape `(n_pix, 2)`; precomputed.
`efficiency`
`grid`	Per-pixel response sample coordinates, shape `(n_pix, 2, grid_dim)`.
`lattice`
`misalignment_lat`
`misalignment_lon`
`pixel_efficiency`
`pixel_values`	Pixel response values, shape `(n_pix, grid_dim, grid_dim)`.
`rotation`
`shift`
`weight`	Simpson-integrated pixel weight, shape `(n_pix,)`.

Methods Summary

`corrected_pm`(pm)	Pointing matrix corrected for shift and rotation.
`from_iactrace`(geo, telescope, camera, *, ...)	Build an instrument by ray-tracing an iactrace telescope and camera.
`from_iactrace_table`(geo, table, *[, ...])	Build an instrument from an already-scanned effective-aperture table.
`project_catalog`(source_coords, source_fluxes)	Project point sources onto pixels, blurred by any misalignment.
`project_diffuse`(hp_values, pm)	Sample a band-integrated HEALPix sky at each pixel.
`project_scattered`(eval_grid_values)	Sample the FOV scattering grid at each pixel.

Attributes Documentation

bandpass¶: Spectral transmission curve, shape (n_wvl,), excluding efficiency.

bandpass_values = <dataclasses._MISSING_TYPE object>¶

blur¶: Misalignment blur width in lattice nodes, [lon, lat], or None.

centers¶: Pixel centres in the offset frame, shape (n_pix, 2); precomputed.

efficiency = <dataclasses._MISSING_TYPE object>¶

grid¶: Per-pixel response sample coordinates, shape (n_pix, 2, grid_dim).

lattice = <dataclasses._MISSING_TYPE object>¶

misalignment_lat = <dataclasses._MISSING_TYPE object>¶

misalignment_lon = <dataclasses._MISSING_TYPE object>¶

pixel_efficiency = <dataclasses._MISSING_TYPE object>¶

pixel_values¶: Pixel response values, shape (n_pix, grid_dim, grid_dim).

rotation = <dataclasses._MISSING_TYPE object>¶

shift = <dataclasses._MISSING_TYPE object>¶

weight¶: Simpson-integrated pixel weight, shape (n_pix,).

Methods Documentation

corrected_pm(pm)[source]¶

Pointing matrix corrected for shift and rotation.

Parameters:: pm (jax.Array, shape (3, 3))
Return type:: jax.Array, shape (3, 3)

classmethod from_iactrace(geo, telescope, camera, *, half_angle, step, wvls, window=None, chunk_size=256, progress=False, misalignment=None, **scan_kwargs)[source]¶

Build an instrument by ray-tracing an iactrace telescope and camera.

Needs the optional nyx[iactrace] dependency.

Parameters:

geo (Geometry)
telescope (iactrace.Telescope)
camera (iactrace.Camera)
half_angle (float) – Half-width of the field to scan, in radians; must clear the camera radius over the focal length.
step (float) – Field-angle lattice spacing, in radians; around an eighth of the angular pixel pitch resolves a pixel response.
wvls (array-like) – Wavelength grid in nm the bandpass is tabulated on.
window (int or None) – Side length of each pixel’s response window, in nodes; None measures it.
chunk_size (int) – Field directions traced per render call.
progress (bool) – Whether to print scan progress to stderr.
misalignment (float, pair of floats, or None) – Initial facet blur model in arcseconds.
**scan_kwargs – Anything else iactrace.analysis.effective_aperture() takes.

Return type:

EffectiveApertureInstrument

classmethod from_iactrace_table(geo, table, *, misalignment=None)[source]¶

Build an instrument from an already-scanned effective-aperture table.

Parameters:

geo (Geometry)
table (path-like or EffectiveApertureTable) – A .npz file written by iactrace.io.save_aperture_table.
misalignment (float, pair of floats, or None) – Initial facet tilt RMS in arcseconds.

Return type:

EffectiveApertureInstrument

project_catalog(source_coords, source_fluxes)[source]¶

Project point sources onto pixels, blurred by any misalignment.

Parameters:

source_coords (jax.Array, shape (n_sources, 2)) – Offset-frame coordinates, already in the detector frame.
source_fluxes (jax.Array, shape (n_sources,)) – Already band-integrated and extincted by the render pipeline.

Return type:

jax.Array, shape (n_pixels,)

project_diffuse(hp_values, pm)[source]¶

Sample a band-integrated HEALPix sky at each pixel.

Parameters:

hp_values (jax.Array, shape (npix,))
pm (jax.Array, shape (3, 3)) – Nominal pointing matrix.

Return type:

jax.Array, shape (n_pixels,)

project_scattered(eval_grid_values)[source]¶

Sample the FOV scattering grid at each pixel.

Parameters:: eval_grid_values (jax.Array, shape (n_lon, n_lat))
Return type:: jax.Array, shape (n_pixels,)

__init__(geo, bandpass, grid, values, *, misalignment=None)[source]¶

Build the instrument.

Parameters:

geo (Geometry)
bandpass (callable) – Maps a wavelength Quantity to transmission.
grid (array-like, shape (n_pixels, 2, grid_dim), or PixelLattice) – Pixel sub-grid coordinates in radians, from which the shared response lattice is recovered; or that lattice directly.
values (array-like, shape (n_pixels, grid_dim, grid_dim)) – Pixel response at the sub-grid points, of the aligned optics.
misalignment (float, pair of floats, or None) – Initial facet tilt RMS in arcseconds, one value or one per axis as [lon, lat]. None means no misalignment.

static __new__(cls, *args, **kwargs)¶