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Cosmic-Ray Rejection by Laplacian Edge Detection

Pieter G. van Dokkum
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Abstract

Conventional algorithms for rejecting cosmic-rays in single CCD exposures rely on the contrast between cosmic-rays and their surroundings, and may produce erroneous results if the Point Spread Function (PSF) is smaller than the largest cosmic-rays. This paper describes a robust algorithm for cosmic-ray rejection, based on a variation of Laplacian edge detection. The algorithm identifies cosmic-rays of arbitrary shapes and sizes by the sharpness of their edges, and reliably discriminates between poorly sampled point sources and cosmic-rays. Examples of its performance are given for spectroscopic and imaging data, including HST WFPC2 images.

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Pieter G. van Dokkum. 2001-08-01. Cosmic-Ray Rejection by Laplacian Edge Detection. https://doi.org/10.1086/323894

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