The CLEAN algorithm is a computational algorithm to perform a

deconvolution In mathematics, deconvolution is the inverse of convolution. Both operations are used in signal processing and image processing. For example, it may be possible to recover the original signal after a filter (convolution) by using a deconvolution ...

on images created in

radio astronomy Radio astronomy is a subfield of astronomy that studies Astronomical object, celestial objects using radio waves. It started in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observat ...

. It was published by Jan Högbom in 1974 and several variations have been proposed since then.The family of CLEAN algorithms
a chapter from the ''MAPPING'' software manual The algorithm assumes that the image consists of a number of point sources. It will iteratively find the highest value in the image and subtract a small gain of this point source convolved with the

point spread function The point spread function (PSF) describes the response of a focused optical imaging system to a point source or point object. A more general term for the PSF is the system's impulse response; the PSF is the impulse response or impulse response ...

("dirty beam") of the observation, until the highest value is smaller than some threshold. Astronomer T. J. Cornwell writes, "The impact of CLEAN on radio astronomy has been immense", both directly in enabling greater speed and efficiency in observations, and indirectly by encouraging "a wave of innovation in synthesis processing that continues to this day." It has also been applied in other areas of astronomy and many other fields of science. The CLEAN algorithm and its variations are still extensively used in radio astronomy, for example in the first imaging of the M87 central supermassive black hole by the

Event Horizon Telescope The Event Horizon Telescope (EHT) is a Astronomical interferometer, telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, wh ...

References

Radio astronomy Computational astronomy {{astronomy-stub