AN/SPS-48
The AN/SPS-48 is a US naval Passive 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 a large number of such ships, and many of these vessels 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.
Operation
A three-dimensional radar is mounted on a base that allows for 360 degrees of rotation. The target can be located at a given azimuth. The range of the target is also identified due to the time it takes the beam to go out and back to the receiver. What makes this radar system different is its ability to detect the height of the target above the surface of the water. With these three pieces of data the radar's central processor has the ability to place the target in an X,Y,Z, 3 dimensional space.