The history of US naval radars is somewhat confusing because of the variety of types of designations employed. These reflect the organizations behind development. During World War II, the US Navy deployed two major radar series: search sets (BuShips) and fire control systems (BuOrd). The former carried over a system consisting of a type letter, eg S (search radar), and a model letter: thus SC is the third US search radar; and SC-S is the fifth modification of SC. The Bureau of Ordnance preferred to use mark numbers, eg Mk 25; modifications within a mark were also numbered, eg Mk 25 Mod 1. However, the earliest fire control radars were also designated under the BuShips system, with the type letter F; thus FH is Mark 8. Such designations were dropped early in the war, but persist on plans drawn as late as 1945.

Three letters were generally used to extend series beyond twenty-five (the letter I was not used); thus RAA, RAB and RAG would be the twenty-sixth, -seventh, and -eighth radio receivers. There were only twenty-four search radars, so none required three letters. Lower-case letters (eg 'a' in SRa) indicated field changes. The prefixes 'X' and 'CX' were reserved for the Navy (NRL) and commercially produced experimental or preproduction sets, eg CXAM, the first US naval radar. These series included all types of electronic equipment. The Army used an entirely different class of designations, its radars being numbered in the Signal Corps Radio (SCR) series. One Army radar, SCR-720, was fitted in limited numbers to US warships at the end of the war.

The fragmented system thus described did not long outlast World War II. Even during the war it proved difficult for Navy and Army (Air Force) to coordinate airborne radar procurement. Early Navy air radars were designated in the same manner (but not the same series!) as the surface sets, so that ASH was the eighth airborne search radar. However, in February 1943 a new universal system appeared, three letters plus a number (platform-type of equipment, and function). For example, APS-4 was the fourth airborne pulsed (radar) search device. New equipment designed after World War II, even when it was specific to the Navy, fitted this pattern with the prefixes 'S' for surface ships and 'B' for submarine. Generally the multiservice designations are prefixed by the letters 'AN' for Army-Navy, as in AN/SPS-6.

• "Naval Weapons of World War Two" by John Campbell
• "The Naval Institute Guide to World Naval Weapon Systems 1991/92" and "Naval Radar" both by Norman Friedman
• "The Evolution of Battleship Gunnery in the U.S. Navy, 1920-1945" article in "Warship International" No. 3, 1991 by William Jurens
• "Battleship New Jersey" by Paul Stillwell
• "Battleships of the US Navy in World War II" by Stephan Terzibaschitsch

• "U.S. Radar Operational Characteristics of Radar Classified by Tactical Application (1943)" at US Naval Historical Center
• Modern-day US Radar Systems listing at FAS