EDO Reconnaissance and Surveillance Systems' (EDO RSS) ES-3701 is a state-of-the-art combined precision Electronic Support Measures (ESM) and radar warning receiver (RWR) system. It was developed to provide an improved performance replacement for all of the lower performance simple design amplitude monopulse systems currently used on ships and submarines. Unlike amplitude monopulse systems, the ES-3701 ESM system provides all of the capabilities required of a modern ESM system for operation in today's difficult electromagnetic environment against today's complex radar threats. It uses the latest phase measurement technology for high-precision monopulse direction-finding, combined with a patented "autohet" receiver to achieve 100% probability of intercept.

The system can operate in an essentially unattended fashion, displaying all intercepted signals, and generating audible and visual alarms for predefined threat signals. The system also supports operator ELINT quality analysis of intercepted signals and operator intervention in the signal identification and platform reporting process.

For training purposes, the system provides a simulation facility in which signals and scenarios can be generated or recorded and played back. Extensive maintenance processes are provided, including signal injection at various points in the system, limited RF signal generation, automated frequency and phase calibration, built-in-test (BIT) in all units, and internally maintained system status tables.

The ES-3701 operates effectively in coastal regions and provides high-performance processing even in the presence of interfering signals. It also takes advantage of the latest software design standards.

One of the key contributors to a ship's Combat System's effectiveness is the ability of the associated ESM system to provide long-range threat detection, accurate threat direction-finding on low level signals, and accurate and positive identification of threat emitters, all while operating in a dense radar signal environment.

Unlike the amplitude comparison monopulse ESM system, the ES-3701 ESM system has the ability to provide accurate association and precise identification of all radar targets for an accurate picture compilation by the Combat System.