Radar Jamming and Deception

- Overview 

Radar jamming and deception are core Electronic Countermeasures (ECM) that use RF signals to overwhelm or mislead enemy radars with noise or false data, using techniques like blanketing screens with noise (jamming) or creating fake targets (deception) to hide real threats, confuse operators, and degrade defense systems, often employing Digital Radio Frequency Memory (DRFM) for sophisticated mimicry. 

1. How it works:

• Jamming (Noise): Transmitting strong signals on the same frequency as the target radar to drown out actual echoes, making it impossible to see real targets (e.g., Barrage Jamming).
• Deception (False Info): Re-transmitting or modifying radar signals to create phantom targets, shift their perceived range/angle, or make decoys seem like real, high-value assets.
• Target Modification: Using physical means like chaff (aluminum strips) or radar-absorbing materials to alter the radar's view of the actual target.

2. Key Techniques:

• Electronic Jamming: Active transmission of noise.
• Deceptive Jamming (Repeater): Captures radar pulses and re-transmits them with alterations (delay, Doppler shift).
• Mechanical Jamming: Using passive reflectors like corner reflectors or decoys to bounce radar energy back confusingly.

3. Purpose:

• To increase uncertainty for the defending system.
• To delay target tracking.
• To protect aircraft or ships from detection and engagement.

Please refer to the following for more information:

• Wikipedia: Radar jamming and deception

- Radar Jammers and Jamming

Radar jammers are electronic warfare tools that emit radio signals to overwhelm or trick radar receivers, either by flooding them with noise (jamming) or creating fake targets (deception) to hide real objects or disrupt tracking, a key part of Electronic Countermeasures (ECM). 

They function by interfering with radar's ability to detect genuine reflections from objects, using methods like blanketing the receiver with noise or generating false echoes, making it difficult for radar to discern real threats from decoys. 

1. How Radar Jamming Works:

• Noise Jamming: Overwhelms the radar receiver with strong radio signals, essentially "blinding" it to actual reflections from targets.
• Deception Jamming: Analyzes the radar signal, then sends back altered or new signals to create false targets, alter range, or confuse the operator about the target's true location or speed.
• Electronic Countermeasures (ECM): A broader term for tactics like jamming and deception, used to protect forces by disrupting enemy sensors and command/control.

2. Types of Jammers:

• Mechanical: Reflects enemy signals in misleading ways (less common now).
• Electronic: Actively transmits new signals, often using advanced Digital Radio Frequency Memory (DRFM) to create sophisticated false targets.

3. Purpose:

• To protect aircraft, ships, or ground forces from radar detection and targeting.
• To degrade the effectiveness of enemy radar systems, from air traffic control to sophisticated missile defense radars.

- Next-generation Radar Jamming and Deception Techniques

Next-generation radar jamming and deception techniques are largely defined by advancements in Digital Radio Frequency Memory (DRFM), the integration of Artificial Intelligence (AI) and Machine Learning (ML), and advanced hardware like Active Electronically Scanned Arrays (AESA). These innovations enable more adaptive, coherent, and autonomous electronic warfare (EW) capabilities. 

Ultimately, the field is an adaptive, continuous "cat-and-mouse" game between electronic attack (EA) and electronic protection (EP) technologies.

A. Key Next-Generation Techniques:

1. AI-Powered Cognitive EW: This is a major trend where systems use AI and ML to sense the electromagnetic environment, learn radar signal patterns in real time, decide on optimal tactics, and execute them without human delay. This is crucial for countering adaptive, frequency-agile radars that constantly change their operational parameters. 

2. Advanced DRFM Deception: Digital Radio Frequency Memory systems continue to evolve, moving beyond simple false target generation to create complex, highly realistic false scenarios. Techniques include:

• Range and Velocity Deception: Manipulating the delay and Doppler shift of retransmitted signals to make targets appear to be at incorrect ranges or speeds.
• Multiple False Target Generation: Overloading radar processing capabilities by generating numerous convincing, simultaneous false targets to hide the actual target.
• Coherent Spoofing: Generating jamming signals that are so well-matched to the victim radar's waveform that the radar receiver cannot discriminate them from a real target echo.

3. AESA-Based Jamming: Active Electronically Scanned Array technology enables jammers to direct highly concentrated energy at specific threats across a wide range of frequencies simultaneously. The US Navy's Next Generation Jammer (NGJ) is a prominent example of an AESA-based system that uses wideband gallium-nitride (GaN) technology to enhance power and frequency coverage. 

4. Interrupted-Sampling Repeater Jamming (ISRJ): A specific DRFM technique that samples and repeats a fraction of the intercepted signal to create multiple false targets against modern wideband radars, some of which can even precede the real target.
Polarization Modulation: Emerging research is exploring methods to modulate the polarization state of jamming signals to generate false targets that also mimic the polarization characteristics of a real target, making them even harder to discriminate with advanced dual-polarization radars. 

5. Coordinated Deception: Utilizing networked systems, such as swarms of drones or towed decoys, to coordinate jamming efforts, generate complex false scenes, and lure anti-radiation missiles (ARMs) away from high-value assets.

B. Countermeasures (Electronic Counter-Countermeasures - ECCM): 

Radar developers are simultaneously creating advanced countermeasures:

• Frequency Agility: Rapidly and randomly changing the radar's operating frequency to make it difficult for jammers to track and jam effectively.
• Low Probability of Intercept (LPI) Radars: Radars designed to be difficult to detect in the first place, using techniques like frequency-modulated continuous-wave (FMCW) or AESA technology.
• Operator Training & Data Fusion: Highly trained operators and systems that fuse data from multiple sensors (radar, IR, optical) can help discern abnormal patterns caused by jamming.
• Anti-Radiation Missiles (ARMs): Weapons designed to home in on the continuous emissions produced by active jammers, forcing a trade-off between using jamming for protection and exposing the platform to attack.