OVERVIEW: Simple ESM Systems (1970s era) are basic passive electronic support devices designed to detect and identify radar and communication signals primarily for threat warning and situational awareness.

GENERAL DESCRIPTION: These 1970s-era ESM systems primarily used analog signal processing to intercept electromagnetic emissions from radar and radio sources. Capable of basic emitter identification through signal parameter measurement (frequency, pulse width, PRF), they provided early warning on naval ships and aircraft. Direction finding was rudimentary, and signal libraries were limited, focusing on known threats during the Cold War.

ROLE SUMMARY:
Category: Electronic Support Measures (ESM)
Primary Use: Basic emitter detection and identification
Function: Passive interception and simple analysis
Platform: Naval vessels, early warning aircraft, ground stations
Integration: Linked to threat alert systems and electronic countermeasure controllers

See Specific information under [Sensors/EW] section.

SOURCE:
Jane’s Electronic Warfare Systems (Historic Editions)
https://en.wikipedia.org/wiki/Electronic_support_measures