MILS meaning in Governmental ?

The Missile Impact Location System or Missile Impact Locating System (MILS) is an ocean acoustic system designed to locate the impact position of test missile nose cones at the ocean's surface and then the position of the cone itself for recovery from the ocean bottom. The systems were installed in the missile test ranges managed by the U.S. Air Force.

The systems were first installed in the Eastern Range, at the time the Atlantic Missile Range, and secondly in the Pacific, then known as the Pacific Missile Range. The Atlantic Missile Impact Location System and Pacific Missile Impact Location System were installed from 1958 through 1960. Design and development was by American Telephone and Telegraph Company (AT&T), with its Bell Laboratories research and Western Electric manufacturing elements and was to an extent based on the company's technology and experience developing and deploying the Navy's then classified Sound Surveillance System (SOSUS). Early studies were done at Bell Laboratories' Underwater Systems Development Department examined the problem then the Bell System's other organizations began implementation. The company and Navy assets that had installed the first phase of SOSUS, starting in 1951, were engaged on MILS installation and activation.

MILS took several forms and each had a unique configuration based on purpose and local water column and bottom conditions. The target arrays were bottom fixed hydrophones connected by cable to the shore stations. A variant, Sonobuoy MILS (SMILS), was composed of bottom mounted hydrophones augmented by air dropped sonobuoys when in use. The third covered wide ocean areas with fixed hydrophones at distant shore sites was termed broad ocean area (BOA) MILS. All systems exploited the SOFAR channel, also known as the deep sound channel, for long range sound propagation in the ocean.