SIGINT

Signals intelligence is the collection and analysis of electromagnetic emissions to produce intelligence. It splits broadly into communications intelligence — intercepting voice and data traffic — and electronic intelligence, which characterizes non-communications emitters such as radars: their frequencies, pulse patterns, locations, and operating modes. Even without reading encrypted content, the metadata is valuable: the density, type, and movement of emitters map an adversary's order of battle and often telegraph an operation before it begins.

Drones have changed the collection platform more than the discipline. Payloads that once required crewed jets or fixed sites now fly on unmanned platforms that orbit for hours close to the target area, and cheap software-defined radios put a capable receiver in a package the size of a lunchbox. The drone itself is also a SIGINT target: its control and video links are emissions that can be detected, geolocated, and traced back to the operator's position, which is frequently more valuable than the aircraft.

SIGINT feeds everything else in electronic warfare. Jamming priorities, frequency deconfliction, and targeting all start from the emitter picture that collection builds, and the loop from detection to jamming or fire is now measured in minutes on active fronts.