Radiofrequency MASINT

MASINT is made up of six major disciplines, but the disciplines overlap and intertwine. They interact with the more traditional intelligence disciplines of HUMINT, IMINT, and SIGINT. To be more confusing, while MASINT is highly technical and is called such, TECHINT is another discipline, dealing with such things as the analysis of captured equipment.

An example of the interaction is "imagery-defined MASINT (IDM)". In IDM, a MASINT application would measure the image, pixel by pixel, and try to identify the physical materials, or types of energy, that are responsible for pixels or groups of pixels: signatures. When the signatures are then correlated to precise geography, or details of an object, the combined information becomes something greater than the whole of its IMINT and MASINT parts.

The Center for MASINT Studies and Research breaks MASINT into:[2]

• Electro-optical MASINT
• Nuclear MASINT
• Geophysical MASINT
• Radar MASINT
• Materials MASINT

Where COMINT and ELINT, the two major components of SIGINT, focus on the intentionally transmitted part of the signal, radiofrequency MASINT focuses on unintentionally transmitted information. For example, a given radar antenna will have sidelobes emanating from other than the direction in which the main antenna is aimed. The RADINT (radar intelligence) MASINT subdiscipline involves learning to recognize a radar both by its primary signal, captured by ELINT, and its sidelobes, perhaps captured by the main ELINT sensor, or, more likely, a sensor aimed at the sides of the radio antenna.

MASINT associated with COMINT might involve the detection of common background sounds expected with human voice communications. For example, if a given radio signal comes from a radio used in a tank, if the interceptor does not hear engine noise or higher voice frequency than the voice modulation usually uses, even though the voice conversation is meaningful, MASINT might suggest it is a deception, not coming from a real tank.

Different from emitter location in SIGINT, frequency analysis MASINT concentrates not on finding a specific device, but on characterizing the signatures of a class of devices, based on their intentional and unintentional radio emissions. Devices being characterized could include radars, communication radios, radio signals from foreign remote sensors, radio frequency weapons (RFW), collateral signals from other weapons, weapon precursors, or weapon simulators (for example, electromagnetic pulse signals associated with nuclear bursts); and spurious or unintentional signals.[3]

See HF/DF for a discussion of SIGINT-captured information with a MASINT flavor, such as determining the frequency to which a receiver is tuned, from detecting the frequency of the beat frequency oscillator of the superheterodyne receiver. This may also be considered unintentional RF radiation (RINT). The local oscillator intercept technique, Operation RAFTER was first made public by a book by a retired senior officer in Britain's counterintelligence service, MI5.[4] The book also discusses acoustic methods of capturing COMINT.

Nuclear and large conventional explosions produce radio frequency energy. The characteristics of the EMP will vary with altitude and burst size. EMP-like effects are not always from open-air or space explosions; there has been work with controlled explosions for generating electrical pulse to drive lasers and railguns.

For example, in a program called BURNING LIGHT, KC-135R tankers, temporarily modified to carry MASINT sensors, would fly around the test area, as part of Operation BURNING LIGHT. One sensor system measured the electromagnetic pulse of the detonation.[5]

While EMP often is assumed to be a characteristic of nuclear weapons alone, such is not the case.[6] Several open-literature techniques, requiring only conventional explosives, or, in the case of high power microwave, a large electrical power supply, perhaps one-shot as with capacitors, can generate a significant EMP:

• Explosively pumped flux compression generators (FCG)
• Explosive and Propellant Driven MHD Generators
• High Power Microwave Sources - Spark gaps or the Vircator

EMP intelligence deals both offensive capability to build, generate particular power vs. frequency spectra, and means of optimizing coupling or other power delivery, and defensive EMP considerations of vulnerability.

Vulnerability has two components:

• Coupling modes possible between the EMP source and the equipment
  • Front door coupling goes through an antenna intended to receive power in the frequency range being generated
  • Back door coupling in which the EMP produces surges in power (including ground) and communications wire.
• The level of energy coupled that will damage or destroy a particular target.

Another aspect of offensive EMP intelligence is to evaluate the ways in which an EMP weapon could improve coupling. One approach involves the device extruding antennas. Another, similar to other precision guided munitions, is to bring the device as close as possible to the target.

Intelligence about EMP defense would consider the deliberate use of shielding (e.g., Faraday cages) or greater use of optical cabling.

The integration and specialized application of MASINT techniques against unintentional radiation sources (RINT) that are incidental to the RF propagation and operating characteristics of military and civil engines, power sources, weapons systems, electronic systems, machinery, equipment, or instruments. These techniques may be valuable in detecting, tracking, and monitoring a variety of activities of interest.(FM2-0Ch9) harv error: no target: CITEREFFM2-0Ch9 (help)