Thales Defense & Security (also known as TDSI, formerly known as Racal Communications and Thales Communications) is a company that develops and provides solutions for the ground tactical, naval and maritime, airborne and avionics, and security domains. It provides tactical communication systems and other electronics products. It offers software-defined radio (SDR) products, combat management systems, radars, airborne acoustic sensors, electro-optic and infrared sensors, helmet-mounted displays, electronic warfare systems, satellite communications technologies and terminals, motion tracking technologies, thermal solutions, data security solutions, sonar detection solutions, and other products and services. The company caters to land tactical communications, aviation and cockpit solutions, naval and maritime c4isr systems, sensors and missile systems, and data security markets.