World's First: Passive Radar Signal Confirms visual UFO-Sighting

Report of www.grenzwissenschaft-aktuell.de, a scientific orientated German UFO journal, which from time to time post English articles as well. Content: a sighting by a police officer in western Germany could be corroborated by a passive radar system of an UFO researcher of German UFO society 'GEP' for the first time.