Electronic Intelligence (ELINT) = information derived from electronic signals that do not contain speech or text (which are considered COMINT).
ELINT Categories
• Technical ELINT / TechELINT = Signal parameters (frequency, bandwidth, amplitude, …), define the capability and role of the emitter -> What is emitting?
• OperationalELINT / OpELINT = Locating specific ELINT targets and threat assessment -> Where is emitter?
• TelemetryELINT / TELINT = Collection, processing and reporting of foreign telemetry signals, e.g. satellite down and uplink signals
-> What info is transmitted?
Most ELINT systems intercept and analyse Radar Signals – or communication signals. Typically theses signals are in the microwave spectrum and therefore have quite a large wavelength.
TechELINT
OpELINT
How to localize a radar, e.g. from space
SENTINEL-1 C-SAR interference analysis. Intro – OSINTEditor
C-SAR Eye – Sentinel-1 data analysis tool – OSINTEditor
5GIT – Demo research – OSINTEditor
-> Patriot locations can be determined using Sentinel-1 data on GEE (Google earth Engine), because they also use a C-Band RADAR
Example RESM
Radar electronic support measures
Compare intercepted Radar signals with an emitter library, like this you can detect the targets you want, for example a certain air defence radar.
ELINT Sensor
A Receiver with a Panoramic View (Wide Band Receiver, WBR is employed to keep an eye on the surroundings, and • A Selective Receiver is used to measure radar waveforms (Super Heterodyne Receiver, SHR)
Payload
ELINT collectors have to be located in the best possible position, a tradeoff between the highest probability of intercepting signals of interest (SOI) and remaining undiscovered. Therefore the collector will have to be deployed in an area where the target can be collected (generally line of sight) without alerting the target of its presence.
ELINT systems on airborne platforms are usually very large/ consist of a high number of antennas. -> long radar wavelength and directed beam nature.
Challenges
The service life of a radar system is generally calculated in decades instead of years. As a result, an ESM or ELINT system should encompass an ever increasing roster of radars, both older and newer, whose profiles might change with passing time as upgrades, parts are changed, and their efficiency alters as emerging innovations are introduced
Various types of radars possess different electro – magnetic identities, therefore a missile defense systems radar would be different from one another, such as rocket seekers, or even radars with same type might very well change through one system toward the next. Furthermore, today’s duplexer, multifunctional radars integrate complex signal modulation methods with harmonic mobility, intra pulse waveforms variations, odd waveform such as pseudo sound modulate, very quick side-lobe changes, digitized beamforming, and a slew of other deceptive tactics.
Example: China C-SAR
Example of ELINT/OSINT. Google Earth Engine Sentinel-1 C-band SAR composite image, where the red areas indicate high abundance of C-band RADAR Signals and therefore these areas indicate possible locations of Chinese RADAR stations.
Example 2: Target signal location detection using ELINT satellite triangulation
If the frequency of a target is known more or less, for example the radar frequency of an air defence system, one need at least 3 satellites with an antenna capable to receive that frequency. There are big ELINT satellite constellations capable of doing so, however the minimum solution is to use 3 satellites in the same orbit directly one after another, like a tandem constellation, just with 3 satellites. Typically, these ELINT payloads are working in an S-band, but most antennas can detect signals in a wide spectrum, for example S, L, P or X-band. The signal will then be detected by the satellites at different times, depending on the distance between the satellites and the target. Now we know, the distance between the satellites and the target and of course we know the position of our own satellites and therefore we can estimate the location of the target, to typically a few hundred meters or better:
Example 3: Detect GPS Jamming
GPS jammed areas can be detected and mapped using a L-band ELINT receiver. It can be detected, because a heavy L-band signal or more commonly several signals and emitters, pretending to be a real GPS-signals, is/ are present and override the weaker real GPS signals.