Marine Detachment, Air Warning Service, Philippines

The Marine Detachment, Air Warning Service, Philippines (active 1941–42) was a United States Marine Corps ground based early-warning radar detachment that provided long range detection and rudimentary fighter direction against Japanese air raids during the Japanese invasion of the Philippines in the early days of World War II. It was the first Marine Corps early warning detachment to participate in combat operations. Initially organized at the Cavite Naval Base in November 1941 as a top secret unit within the headquarters of the 1st Separate Marine Battalion, the detachment operated an SCR-270 long range radar on the Bataan Peninsula for the duration of the Battle of Bataan.

Source: Wikipedia — Marine Detachment, Air Warning Service, Philippines (CC BY-SA 4.0)