A position, often in polar coordinates, of an object located by radar

plural of LU

(historical) A system used by the US Navy in the late 19th century to enable ship-to-ship communications at night. Each installation used a series of eight double lamps (four red and four white) hu...

(US, urban studies) The large-scale migration of white people from racially mixed urban regions to more racially homogeneous suburban or exurban regions.