The H2X radar, nicknamed the "Mickey set", provided a ground mapping capability for both navigation and in daylight when overcast (and at night) for the USAAF during World War II.

The H2X system replaced the British H2S radar. It used a shorter wavelength that gave a sharper picture. The U.S. converted fifty B-24 Bombers into Pathfinder Aircraft equipped with the H2X radars. The radar dish replaced the ball turret of the Pathfinders. The "Mickey set" was installed in the radio room and navigational and bombing information was given to the Navigator and Bombardier. These aircraft recorded 1132 sorties during World War II. The H2X in production was called the AN/APS-15 and was a three-centimeter radar. It was designed to see through clouds for bombing as well as a navigation aid. In Europe Several P-38s fighters were also converted in carrying H2X radar in the nose, along with an operator/navigator to obtain radar maps of German targets.

In the Pacific theater, B-29’s were equipped with the improved H2X radar called the AN/APQ-13, a ground scanning radar developed by Bell, Western Electric and MIT. The radome was carried on the aircraft belly between the bomb bays and was partially retractable. The radar operated at a frequency of 9375 ± 45 megacycles and used a superheterodyne receiver. The radar was used for high altitude area bombing, search and navigation. Computation for bombing could be performed by an impact predictor. A Range Unit permitted a high degree of accuracy in locating beacons.

After the war, late 1945, the APQ-13 became the first military radar converted to a domestic peacetime application as a storm warning radar. About thirty systems were converted and installed on military bases. It was replaced by the CPS-9 system in 1949.