The Cryptologic Technician Technical (CTT) rating:

Cryptologic Technician Technical (CTT). CTTs perform a variety of technically-intensive duties, both afloat and ashore, associated with processing and interpreting RADAR emissions for tactical and strategic value. They operate Electronic Intelligence (ELINT)/Electronic Support (ES) receiving/processing systems and peripheral equipment to provide threat assessments, situational awareness and Indications and Warnings (I&W) in addition to formulating Electronic Attack (EA) techniques and tactics. Additionally, CTTs record and analyze RADAR data to develop and maintain RADAR libraries for strategic analysis and development of deception techniques. They operate and maintain ES and EA systems permanently installed on ships. CTTs perform their duties on ships, submarines, aircraft, patrol craft and at shore commands in the U.S. and overseas. CTTs also augment U.S. Special Operations Forces and Expeditionary Warfare forces abroad.

Source: Navy Learning and Development Roadmap.