query: Who developed the first VHF-band radar system?
passage: Radar in World War II
Germany has a long heritage of using electromagnetic waves for detecting objects. In 1888, Heinrich Hertz, who first demonstrated the existence of these waves, also noted that they, like light, were reflected by metal surfaces. In 1904, Christian Hülsmeyer obtained German and foreign patents for an apparatus, the Telemobilskop, using a spark gap transmitter that could detect ships and prevent collisions; this is often cited as the first radar, but, without directly providing range, it does not qualify for this classification. With the advent of the radio tube and electronics, other detection-only systems were developed, but all used continuous waves and could not measure distance.
passage: Walter Rotman
Walter Rotman (August 24, 1922 – May 19, 2007) was an American scientist known for his work in radar and antenna design. Among his inventions were the Rotman lens, the sandwich wire antenna, and the trough waveguide.