detected ships at 1,000 yards and vehicles at 250 feet, results far inferior to what the Navy obtained on longer wavelengths. By 1936, the effort had reached a dead end, and researchers reluctantly adopted the Navy's pulse techniques.

The advantages of microwaves were well understood by the British, German, and American programs: compact antennas that could fit in aircraft, narrow beams for precise tracking and clearer displays, and better detection of low-flying planes that slipped beneath longer-wavelength radars. But none had solved