# Description¶

The hlsp step is one of the coronagraphic-specific steps in the coron sub-package. It produces high-level science products for KLIP-processed (PSF-subtracted) coronagraphic images. The step is currently a prototype and produces two simple products: a signal-to-noise ratio (SNR) image and a table of contrast data. The SNR image is computed by simply taking the ratio of the SCI and ERR arrays of the input target image. The contrast data are in the form of azimuthally-averaged noise versus radius. The noise is computed as the 1-sigma standard deviation within a set of concentric annuli centered in the input image. The annuli regions are computed to the nearest whole pixel; no sub-pixel calculations are performed.

Note

This step is not currently included in the calwebb_coron3 pipeline, but can be run standalone.

# Arguments¶

The hlsp step has one optional argument:

--annuli_width

which is an integer parameter with a default value of 2 and is used to specify the width, in pixels, of the annuli to use when computing the contrast curve data.

# Inputs¶

## 2D image¶

Data model

ImageModel

File suffix

_psfsub

The input is the KLIP-processed (PSF-subtracted) image to be analyzed.

# Outputs¶

## 2D SNR image¶

Data model

ImageModel

File suffix

_snr

The computed SNR image.

## Contrast table¶

Data model

ContrastModel

File suffix

_contrast

The table of contrast data, containing columns of radii (in pixels) and 1-sigma noise.

# Reference Files¶

The hlsp step does not use any reference files.