What are Electronic Support Measures (ESM) used for?

Electronic Support Measures (ESM) are specifically designed for detecting and recording electronic emissions. This capability allows military forces to gather intelligence on enemy radar, communications, and other electronic systems. ESM systems analyze the frequency, waveform, and characteristics of these emissions to identify and locate transmitters, providing critical situational awareness and targeting information.

By identifying enemy electronic signals, ESM enhances a platform's ability to evade detection, navigate through threats, and execute maneuvers in a tactical environment. This function is essential for maintaining a strategic advantage over adversaries, making it a key component in modern warfare.

The other options listed do not align with the primary purpose of ESM. Measuring ship hull integrity and determining ship speed are not related to electronic emissions, and performing maintenance on radar units focuses on the operational readiness of equipment rather than on the collection of intelligence through electronic means.