August 23rd, 2021 - Introduction to RF Electromagnetic Warfare

In the past, different techniques and strategies were used to evaluate enemy plans and avoid any possible attacks, but most were imperfect and carried some risk of misinterpretation. In 1904, Electronic warfare changed the landscape of military reconnaissance. This genre of warfare, using dynamic military-grade jamming abilities, was about intercepting and sabotaging enemy communication lines transmitted through RF equipment. 

HIGH-QUALITY SMART RF WARFARE SYSTEMS

High-quality Smart RF warfare systems are used today in military and intelligence institutes worldwide to protect warfighters and military resources, especially among global superpowers like the United States and China, and their importance is only expected to grow in the future. For instance, in World War II, the advent of radar systems revolutionized both aerial and naval combat. Now, however, many countries also incorporate intelligent radar jammers with high-power RF systems to disable enemy attacks, as a countermeasure to radar. Electronic Warfare in modern times, called Cyber Warfare, is not only about locating enemy positions and analyzing enemy signals to gather intelligence on their movements: it is also about countering these same intelligence-gathering methods, discovering potential weaknesses in one’s own system, and creating misdirection for any opposing EW groups.

MAJOR FUNCTION

One major function of RF EW systems, as touched on above, is stealth, or the ability to circumvent enemy countermeasures. Modern Anti-ship ballistic missiles (ASBM), for example, take advantage of a property called sea skimming. When a missile flies as close to the surface as possible, skimming, its presence lingers within the enemy radar’s clutter—a detection range obfuscated by mundane things like precipitation and land. This drastically reduces the interval of time between enemy alarm and missile impact. As well, ASBMs rely on a terminal guidance system. These systems only activate full control of the ASBM in what is called the terminal phase, or five miles before impact, minimizing the detectability of the missile in flight. RF Equipment is a focal point of both attack and defense: high-quality systems are required to properly guide the missile in its brief terminal phase, while more sophisticated radar systems can reduce clutter and detect skimming missiles earlier.

Beyond stealth, these Cyber Warfare systems are used to deceive the enemy. Exposed radar antennas are susceptible to outside tampering, or computerized jamming, which is achieved by synchronizing with the spinning radar.  If completely unsecure, an enemy’s radar can then be deceived into identifying fake aircrafts at predetermined locations. The deceiving party could, if they wish, generate thousands of aircrafts flying in formation, with precise control over each one. Ships also have several ways of trying to confuse submarines varying from simple towed decoys, which mimic the sound of a ship, to sonars which frequency hop to make it harder to pinpoint the source. Propellers can be made to make different noises than what a submarine might expect to hear from a naval vessel.

Methods such as these, as well as other interruptive EW implements, collectively fall under MIJI incidents (Meaconing, intrusion, jamming and interference). Missiles are designed to use various sorts of guidance and attack modes, just as ships have multiples methods of EW defenses. The ESM (electronic support measures) portion of the jammer continuously monitors the missile radar while it is jamming so it can both 'tweak' the jammer signal, and to also verify that the radar is still operating. This helps assure two things: that there is no HOJ (Hone on Jam) targeting system homing in on the jamming presence, and that resources aren’t being wasted jamming inactive radars.

MIJI CLASSIFICATION

The other two incidents that full under MIJI classification are intrusion and meaconing. Intrusion involves a party fooling an enemy into believing they are a friendly radio station, thus allowing for the insertion of false information into their network. This takes place on the radiofrequency side of the network, and is often referred to as Spoofing. Meaconing is similar, but you are fooling the enemy into thinking that you are a radio navigation system. For example, if one receives a GPS signal and then rebroadcasts it slightly out of time, this will fool the GPS into thinking it was at some other location than where it was. This method can send stealth drones and other GPS-reliant units off-course.

Spoofing (intrusion) happens inside the network, on the electromagnetic (radio) side of the system, and there are many means of intrusion: one of which is to intrude from the radio side of the network. An example of spoofing in an IP-based network would be to set up a false user node or server. This can happen entirely from within the network, and if the node were a false GPS, it could then report false timing or location data to other systems on the network. This is why it is important to distinguish if it is spoofing within the network or intrusion and meaconing from the radio side of the network.

As the means of causing MIJI incidents evolve, so too does countering the countermeasures, or the pursuit of effective ECCM (Electronic Counter-Countermeasures). Many radio and radar systems use various spread spectrum systems to counter jamming. These systems often also use encryption, a way of nesting information behind a private cypher or sequence. Encrypted systems also provide a way to verify authentication, and thus is a countermeasure against intrusion as well. Encryption does not necessarily help if all the enemy is doing is rebroadcasting (GPS meaconing), since this does not occur within the system—so authentication is not required. The systems will therefore need other methods to detect rebroadcasting. ESM is the baseline for all ECM systems & capabilities, and one cannot easily function without the other. Without the ESM receivers being closely coupled to the ECM "jammers," these jammers would not be able to select the correct frequency, or timing alignment to jam effectively; this also allows the jammer to properly track any changes in frequency, PRF or PW (in case the radar is shifting any of those parameters).

Intelligent RF warfare, with its ever-evolving technologies, is the future of RW in many countries. Improvements in the accuracy of data transmission will decrease the likelihood of friendly fire or civilian casualty accidents, and it will also decrease the ability of insurgents to employ Improvised Explosive Devices (IEDs) in populated areas: Electronic Warfare defines the modern-day battlefield. They can confuse the enemy, track communications, attack enemy equipment, and more, without ever using guns or other weapons.