The AN/SPS-48 is a US naval electronically scanned array, air search three-dimensional radar system manufactured by ITT Exelis and deployed in the 1960s as the primary air search sensor for anti-aircraft warships. The deployment of the AN/SPY-1 and the end of the Cold War led to the decommissioning of many such ships, and many of these vessel's AN/SPS-48 sets were reused on aircraft carriers and amphibious ships where it is used to direct targets for air defense systems such as the Sea Sparrow and RIM-116 SAM missiles. Existing sets are being modernized under the ROAR program to AN/SPS-48G standard for better reliability and usability.
An SPS-48E radar antenna (the large square panel) aboard USS Theodore Roosevelt (CVN-71).
AN/SPS 48e on board the USS Ronald Reagan (CVN-76) .
Masts of USS Macdonough (DDG-39) showing an SPS-48 radar near the center of the image
In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas.
The general theory of an electromagnetic phased array also finds applications in ultrasonic and medical imaging application and in optics optical phased array.
US PAVE PAWS active phased array ballistic missile detection radar in Alaska. Completed in 1979, it was one of the first active phased arrays.
Closeup of some of the 2677 crossed dipole antenna elements that make up the plane array. This antenna produced a narrow "pencil" beam only 2.2° wide.
Active Phased Array Radar mounted on top of Sachsen-class frigate F220 Hamburg's superstructure of the German Navy
AN/SPY-1A radar installation at National Severe Storms Laboratory, Norman, Oklahoma. The enclosing radome provides weather protection.