What is ELINT?

Electronic Intelligence (ELINT) can be defined as the process of intercepting and analyzing radio waves, radio pulse and other radio signals for surveillance purposes. It is used by intelligence agencies around the world to identify and monitor enemies or potential threats. ELINT usually means the evaluation of 'non-communication' signals - not voice or text - These include intercepting signals from radars, missiles and guidance systems, aircrafts etc. The intercepted signals are then further analyzed to information like angle of arrival, frequency of electromagnetic radiation by the emitter, pulse width, pulse repetition period, beam width of the emitter’s antenna, etc. This information is then used to identify the type of emitter, its travel path and location.

The interception of radar signals is one of the main parts of ELINT. Radar signals can be used to detect aircrafts and ships from the electromagnetic radiation that they emit from their radar. To do this it is important to know the characteristics of the target country’s aircraft detecting radar. This can also be derived by identifying patterns in the data captured, however this is getting tougher as modulation standards and security protocols are getting more advanced. Once identified, the target radar can then be physically eliminated (hard kill) or neutralized with the help of a suitable jammer (soft kill).

To avoid detection, ships and aircraft need to evaluate when and how to use their radar to counter ELINT efforts of their enemies.

ELINT can be broadly classified into three types:

TechELINT: This deals with interception, modes of operation, identifying, recording, and documenting radiated electromagnetic energy. The intercepted information can be used to figure our the location of the emitter and other critical information. For example, two TechELINT monitoring devices can be used to identify the location of the emitter of interest using the triangulation method i.e each device evaluates the angles of arrival of ELINT data from the emitter and then and used this information to estimate the location. TechELINT is very crucial to the design of equipment for radar detection, countermeasure, or counter-weapons equipment.

OpELINT: Operational ELINT concentrates on searching, intercepting, locating, specific ELINT targets, and determining its operational patterns. The information is mostly gathered to exploit the target equipment in support of the military actions. OpELINT also provides threat assessments, which is also known as “tactical ELINT.” OpELINT supports military operational planners and tactical military commanders on the battlefield.

TELINT: TELINT is an older form of ELINT. It was based on collecting, analyzing, and reporting foreign telemetry signals. This is now called Foreign Instrumentation Signals Intelligence (FISNIT). Its mode of operation closely resembles TechELINT. TELINT is a critical source of performance information on foreign missiles and space vehicles while they are being developed and tested. TELINT can also provide operational information on foreign satellites and space vehicles.

ELINT is one part of SIGINT (Signal Intelligence) however, does not include information gathered from communications between people. Click here to learn about SIGINT.