Signals Intelligence Operational Platforms PDF

Signals intelligence operational platforms are employed by nations to collect signals intelligence, which is intelligence-gathering by interception of signals, whether between people (i.e., COMINT or communications intelligence) or between machines (i.e., ELINT or electronic intelligence), or mixtur...

Signals intelligence operational platforms are employed by nations to collect signals intelligence, which is intelligence-gathering by interception of signals, whether between people (i.e., COMINT or communications intelligence) or between machines (i.e., ELINT or electronic intelligence), or mixtures of the two. As sensitive information is often encrypted, signals intelligence often involves the use of cryptanalysis. However, [traffic analysis](https://en.wikipedia.org/wiki/Traffic_analysis#COMINT_metadata_analysis)---the study of who is signalling whom and in what quantity---can often produce valuable information, even when the messages themselves cannot be decrypted. One of the premier ELINT data collection platforms is a modified US Air Force RC-135U aircraft. The primary function of these TechELINT specially configured aircraft is ELINT reconnaissance and surveillance. They collect, analyze, and sometimes locate foreign target electronic signals to help determine detailed operating characteristics and capabilities. They have been in operation, with a continuing series of advanced configurations, since 1964. Another long-time ELINT collection platform is the US Army GUARDRAIL aircraft. This aircraft is configured to locate enemy fire control radars and thus provide OpELINT. The aircraft can fly near or over a battlefield and communicate directly with Army and Air Force units. The GUARDRAIL collection and related analysis and reporting efforts have served in conflicts starting with the Vietnam War through DESERT STORM in 1991. During the Cold War many technological advances were made in ELINT collection and analysis equipment. These advances made increased capabilities possible with more reliable configurations and by consuming less electrical power. As the "state-of-the-art" of foreign radar and other electronic equipment advanced, ELINT receivers had to keep pace. One such receiver, developed in the 1970s for both ground site and airborne use, was the QRC-259. Some thirty to forty receiver systems were deployed and operated into the 1990s.