ESL Incorporated

ESL Incorporated, or Electromagnetic Systems Laboratory, was a subsidiary of TRW, a high technology firm in the United States that was engaged in software design, systems analysis and hardware development for the strategic reconnaissance marketplace. Founded in January 1964 in Palo Alto, California, the company was initially entirely privately capitalized by its employees. One of the company founders and original chief executive was William J. Perry, who eventually became United States Secretary of Defense under President Bill Clinton. Another company founder was Joe Edwin Armstrong. ESL was a leader in developing strategic signal processing systems and a prominent supplier of tactical reconnaissance and direction-finding systems to the U. S. military. These systems provided integrated real-time intelligence.

Most of TRW—including ESL—was acquired by the Northrop Grumman Corporation in December 2002.

ESL primarily supplied domestic intelligence agencies, NASA and the U.S. military, but had certain direct relations with the North Atlantic Treaty Organization (NATO) and also provided some services for a variety of state agencies. Principal historic areas of competence are: (a) reconnaissance systems; (b) data communications systems (including advanced sonar and laser light scattering); (c) phased array radar surveillance systems; (d) advanced data processing systems; and (e) environmental systems. The company employed a large technical staff, most of them holding advanced academic degrees.

ESL was heavily involved in reverse engineering and played a role in the development of Stealth Technology.