Gather intelligence using open information, data, and software. (i) Open information: information available in everyday life, such as internet, broadcasting, papers, and journals.
HUMINT
Intelligence gathered by humans through activities (e.g., spying, undercover operation). (i) White agent: can collect open information but espionage is not permitted. (ii) Black agent: steals confidential information (first-class confidential information, high-quality information) in secret.
TECHINT
Technology and information assets are used to gather enemy intelligence. (i) IMINT: UAV, reconnaissance planes, satellites, etc., are used to gather information. (ii) SIGINT: signals such as radio waves and radar signals are analyzed to gather information. (iii) MASINT: devices other than IMINT and SIGINT are used to gather information.