High Quality Content by WIKIPEDIA articles! Oboe was a British aerial blind bombing targeting system in World War II, based on radio transponder technology. Oboe accurately measured the distance to an aircraft, and gave the pilot guidance on whether or not they were flying along a pre-selected circular route. The route was only 35 yards wide, allowing for much greater accuracy than competing systems like Gee. The curved path Oboe-equipped aircraft followed was quite evident to German radar operators, who came to call the system "Boomerang" after the arc segment left on their displays as the aircraft appeared and disappeared out of range.