Artifact (error)

In natural science and signal processing, an artifact or artefact[1] is any error in the perception or representation of any information introduced by the involved equipment or technique(s).

Physicians typically learn to recognize some of these artifacts to avoid mistaking them for actual pathology.

In ultrasound imaging, several assumptions are made from the computer system to interpret the returning echoes.

Offending artifacts may obscure, distort, or completely misrepresent the true underlying electrophysiological signal sought.

All those echoes must be filtered in order to obtain the position, velocity and type of the real targets that may include aircraft, and weather.

Diffraction spikes and the Airy disk are optical artifacts caused by the diffraction of light through the aperture of an optical system.
Radar multipath echoes from a target cause ghosts to appear.