Which of the following are the two main types of signals intelligence?

The two main types of signals intelligence are Communications Intelligence (COMINT) and Electronic Intelligence (ELINT). COMINT specifically deals with the interception and analysis of communication signals, which can include telephone calls, emails, and other forms of human communication transmitted through various means. ELINT, on the other hand, focuses on the intelligence derived from electronic signals that are not intended for communication, such as radar emissions or signals from non-communication devices.

These two areas are critical in gathering information about adversaries' capabilities and intentions, and they often work in conjunction to provide a comprehensive understanding of the electromagnetic spectrum and its usage by potential threats. Together, COMINT and ELINT are essential components of the broader field of signals intelligence, enabling analysts to interpret and utilize data derived from various electronic sources effectively.