Electronic Attack: An Overview of Electronic Warfare Part 4
December 21, 2018Mario LaMarche
Who remembers that scene in the movie Spaceballs where Lone Starr jams the enemy radar using raspberry jam, causing it to lose the “bleeps, the sweeps, and the creeps”? While Mel Brooks does show what electronic warfare can do, the details aren’t exactly accurate. In this post, we will clear up some of these details in our discussion on electronic attack.
M. B. (Director). (1987). Spaceballs. United States: MGM.
What is Electronic Attack?
Electronic attack (EA) is a key component of electronic warfare and includes the set of technologies and methods that use electromagnetic energy or anti-radiation weapons to attack personnel, facilities or equipment. Most commonly, EA is used to impact an adversary’s use of the electromagnetic spectrum (EMS).
For example, an anti-radiation missile such as AARGM will follow an enemy’s radar signal back to the transmitter, destroying the enemy’s ability to use radar for anti-aircraft operations. There are many other examples of EA applications, but in this article we will focus on how electromagnetic energy is used against an enemy radar system.
In my previous post we discussed electronic support, and more specifically, radar warning receivers. We now return to the example from that article. An aircraft is flying through a hostile area when suddenly an alarm goes off indicating that it has detected an enemy’s search radar. A few seconds later, the radar warning receiver detects the targeting radar from a ground-to-air missile. In this case, the role of the electronic support system is to warn the pilot of the threat; however, it quickly becomes the role of the electronic attack system to neutralize the threat by attacking the missile’s targeting radar.
How do Radar Jammers Work?
Radar jammers are a type of electronic attack technology that either blinds a radar with high-power noise or generates false targets to obscure the true location of the target. There are two approaches to utilizing radar jammers. Self-protection jammers are installed directly on the platform they are protecting, while support jammers attack the radar from a separate location to protect other targets from an enemy radar.
From the previous post on radar technology, we recall that a radar system identifies a target when the energy reflected from the target is greater than the radar receiver’s noise floor. If the reflected signal is below the noise floor, it becomes much more difficult to recover. By transmitting high-power noise, a jammer can cause the noise floor of the radar receiver to increase, thereby decreasing the range and sensitivity. If the noise power is high enough, it can saturate the radar receiver, resulting in non-linearities that completely blind the system. While generating this much power is difficult, advancements in broadband GaN amplifier technology are enabling new types of radar jamming systems.
A more complex approach is to modify the radar signal to create false targets. This usually involves a digital RF memory (DRFM) system that receives the radar signal, modifies it, and then retransmits the modified signal. Using high-performance, low-latency hardware, the radar signal is either down-converted and digitized or directly digitized. Real-time processing modifies the signal by altering parameters such as the phase delay. The modified signal is then converted back to analog and transmitted to the radar receiver. The digital signal processing allows for a wide range of custom algorithms that create false targets or perform other operations to obscure the true location.
While easy to describe, implementing this technology is extremely difficult. The system must have very low latency such that it can digitize and process the radar signal in real time. Similarly to the radar warning receivers described in my previous post, the DRFM systems must be broadband with low noise figure in order to maximize flexibility and range. On top of all this, the constantly changing threats necessitate a system that can easily be updated through the adoption of an open architecture, such as OpenRFM™.
The New Global Reality
It isn’t just the US and our allies that have advanced electronic attack capabilities. Russia demonstrated their advanced electronic warfare capabilities during the conflict in eastern Ukraine. Using UAVs and other platforms, they were able to jam satellite and radio communication as well as perform GPS spoofing. Additionally, they were able to track the Ukrainian positions by monitoring their RF transmissions and even send disturbing text messages to the Ukrainian solders in order to lower moral.
In the final post of this series, we will look at what can be done to protect against an adversary’s use of electronic attack.