xlens.simulator.noise

Pipeline task for adding correlated or uncorrelated noise to coadd exposures.

Classes

`AddNoisePipeConnections`	Butler connections for `AddNoisePipe`.
`AddNoisePipeConfig`	Configuration for `AddNoisePipe`.
`AddNoisePipe`	Pipeline task that adds noise to a simulated coadd exposure.

Functions

get_noise_array(→ numpy.typing.NDArray)

Generate a noise realisation, optionally with spatial correlation.

Module Contents

get_noise_array(*, seed_noise: int, noise_std: float, noise_corr: numpy.typing.NDArray | None, shape: tuple[int, int], pixel_scale: float) → numpy.typing.NDArray[source]

Generate a noise realisation, optionally with spatial correlation.

Parameters:

seed_noise (int) – Random seed for reproducibility.
noise_std (float) – Standard deviation of the noise (before correlation scaling).
noise_corr (NDArray or None) – Normalised noise correlation kernel. When None, independent Gaussian noise is drawn.
shape (tuple[int, int]) – (height, width) of the output array.
pixel_scale (float) – Pixel scale in arcseconds, passed to anacal.noise.simulate_noise.

Returns:

Two-dimensional noise array.

Return type:

NDArray

class AddNoisePipeConnections(*, config=None)[source]

Bases: lsst.pipe.base.PipelineTaskConnections

Butler connections for AddNoisePipe.

noiseCorrImage[source]

exposure[source]

simExposure[source]

class AddNoisePipeConfig[source]

Bases: lsst.pipe.base.PipelineTaskConfig

Configuration for AddNoisePipe.

idGenerator[source]

survey_name[source]

galId[source]

rotId[source]

noiseId[source]

validate()[source]

setDefaults()[source]

class AddNoisePipe(**kwargs: Any)[source]

Bases: lsst.pipe.base.PipelineTask

Pipeline task that adds noise to a simulated coadd exposure.

_DefaultName = 'AddNoisePipe'[source]

ConfigClass[source]

runQuantum(butlerQC, inputRefs, outputRefs) → None[source]

run(*, exposure: lsst.afw.image.ExposureF, seed: int, band: str, noiseCorrImage: lsst.afw.image.ImageF | None = None, **kwargs)[source]

Add noise to an exposure and return the result.

Parameters:

exposure (afwImage.ExposureF) – Input simulated coadd exposure (modified in place).
seed (int) – Base seed from the pipeline’s ID generator.
band (str) – Photometric band label.
noiseCorrImage (afwImage.ImageF or None, optional) – Noise correlation kernel image. When None, uncorrelated Gaussian noise with default survey variance is used.

Returns:

Struct with simExposure attribute containing the noisy exposure.

Return type:

lsst.pipe.base.Struct