Clutter
From Glossary of Meteorology
clutter
Undesirable echoes on radar displays. For a weather radar, clutter usually refers to echoes from ground targets in the main lobe or sidelobes of the antenna pattern (ground clutter) but might also refer to apparent echoes caused by interference from other radar or radio sources.
For tracking or navigational radars, echoes from precipitation may obscure the targets of interest and are called weather clutter.
See cancellation ratio, clutter rejection.
See cancellation ratio, clutter rejection.