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Exploring the Electronic Warfare Extension of SkySim: Jamming and Disturbance Filtering

Written by Peter Green | Oct 09, 2024

This article explores SkySim's Electronic Warfare extension, simulating radar jamming techniques and countermeasures with FreeScopes for advanced disturbance filtering and analysis.Following the discussion on the civil applications of SkySim and its integration with FreeScopes, we now turn our attention to its more advanced capabilities: electronic warfare (EW) simulations. SkySim’s EW extension and FreeScopes Disturbance Filtering & Analysis modules allow for an in-depth exploration of radar jamming techniques and the methods used to counter them. While the previous blog focused on radar applications in civil sectors like air traffic control, this sequel delves into EW and the mechanisms employed to protect radar systems from interference, such as jamming, which can also have implications in civilian contexts like critical infrastructure protection.

Understanding Radar Jamming

Radar jamming involves emitting signals that interfere with the normal operation of radar systems.

The goal is to confuse or overwhelm the radar, making it difficult to detect or track targets accurately. SkySim's EW module focuses on simulating different types of jamming, including:

  1. Barrage Jamming: A broad-spectrum jamming technique that transmits signals across a wide range of frequencies, including those used by radar systems. This approach is simple but inefficient because much of the energy is wasted outside the radar’s operating frequency.

  2. Spot Jamming: A more focused technique, spot jamming targets a specific radar frequency, concentrating energy in a narrow band. It is more efficient but can be countered if the radar shifts its frequency.

  3. Swept Spot Jamming: This technique periodically shifts the jamming frequency across a small band, increasing the chance of hitting the radar’s operating frequency without wasting energy on irrelevant frequencies.

These jamming techniques are widely used in electronic warfare to disrupt radar systems. SkySim, combined with FreeScopes, allows users to simulate these jamming methods and analyze their effects on radar performance.

Jamming Simulation in SkySim

SkySim offers comprehensive tools for simulating radar jamming scenarios. Users can manually activate jamming in the admin panel, select the type of jamming—barrage or spot jamming—and configure jamming power in decibels. FreeScopes, through its visualization tools like the Plan Position Indicator (PPI) and A-scope, provides real-time feedback on how the jamming impacts radar signals.

For instance, when barrage jamming is activated, the radar signal becomes cluttered with noise, making target detection difficult. Similarly, spot jamming focuses the noise on a specific radar frequency, and by visualizing this through the PPI, users can see the degradation in signal clarity. These simulations allow students and trainees to understand the impact of various jamming strategies on radar performance.

FreeScopes Disturbance Filtering: Overcoming Jamming

SkySim’s EW extension isn’t just about simulating attacks. It also includes tools to counter them through disturbance filtering and jamming detection algorithms. FreeScopes Disturbance Filtering & Analysis modules offer exercises that help users learn how to filter out jamming signals and restore radar functionality.

Some of the key algorithms and filters include:

  1. Barrage Jamming Detection: This algorithm identifies barrage jamming signals by analyzing the covariance of the reflected radar signal. It filters the data to enhance the visibility of potential targets hidden within the jammed signal.

  2. Spot Jamming Detection: Spot jamming detection leverages statistical analysis and correlation techniques to locate targets obscured by concentrated noise. By correlating the radar’s actual signal with pre-recorded template signals, the system can detect where the jamming is taking place and isolate the target.

  3. Range Gate Pull-Off (RGPO) Detection: RGPO jamming is a deceptive tactic used to confuse radar systems by altering the apparent distance of a target. The RGPO detection algorithm in FreeScopes identifies this by comparing radar reflections over multiple rotations and detecting any discrepancies in range that indicate jamming. This is visualized on the PPI, showing how a target's position changes due to jamming interference.

Exploring Jamming Detection Algorithms

SkySim’s Electronic Warfare module offers a range of jamming detection algorithms that ensure radar systems remain functional under electronic interference.

  1. Jamming Detection Algorithms focus on identifying and filtering out common jamming types like barrage and spot jamming, enhancing target visibility even in noisy environments.

  2. RGPO Detection Algorithm counters range-gate pull-off jamming by analyzing discrepancies in target range data across multiple radar rotations, ensuring accurate tracking.

  3. Prediction-Based RGPO Detection Algorithms use velocity gating, target association, and predictive models to maintain target tracking, even when faced with sophisticated jamming techniques.

  4. SASP Deception Detect applies statistical and adaptive processing to identify and counter advanced deception jamming, ensuring reliable target detection in dynamic environments.

These algorithms equip radar systems to handle various forms of jamming, maintaining radar performance and target detection in contested scenarios.

Advanced Filters: MTI, Clutter-Map, Kalman, MTD, Doppler Phase Shift, and SASP Enhanced Disturbance Filters

SkySim’s EW module, along with FreeScopes, provides a suite of enhanced disturbance filters that allow users to tackle complex jamming scenarios. These filters significantly improve the radar's ability to distinguish between real targets and noise, even in heavily jammed environments.

Each filter focuses on different aspects of signal processing and target detection, enabling the radar to maintain performance despite interference.

MTI (Moving Target Indication) Enhanced Disturbance Filter

The MTI filter is designed to discriminate between moving and stationary objects, particularly in environments cluttered with stationary objects like buildings or terrain. This filter enhances radar performance in detecting moving targets, even when jamming is employed to obscure the signal. It is particularly effective in civil applications, such as air traffic control, where distinguishing between stationary and moving objects is crucial.

Clutter-Map Enhanced Disturbance Filter

The Clutter-Map filter analyzes the environment and builds a map of stationary objects or clutter. This map allows the radar system to ignore non-moving elements in the radar return, focusing only on moving targets. In jamming scenarios, this helps the radar identify genuine targets that might otherwise be masked by stationary noise or background reflections.

Kalman Enhanced Disturbance Filter

The Kalman filter takes disturbance filtering a step further by incorporating predictive algorithms to track the real-time movement of targets. It uses the known physics of a target's motion (such as velocity and acceleration) to predict its position even when the radar signal is compromised by jamming. This predictive tracking enables the radar to follow a target’s trajectory even when it’s temporarily obscured by interference. Kalman filters are widely used in both military and civilian radar systems for their accuracy in dynamic environments.

MTD (Moving Target Detection) Enhanced Disturbance Filter

The MTD filter is particularly effective at isolating moving targets from clutter and jamming. It builds on the principles of MTI but adds enhanced velocity gating and target association capabilities, making it more suitable for detecting fast-moving targets. This is critical in scenarios where objects with different velocities need to be tracked simultaneously, such as in high-traffic airspace or maritime environments where multiple moving objects may be present.

Doppler Phase Shift Enhanced Disturbance Filter

The Doppler Phase Shift filter focuses on analyzing the phase shift of the radar signal caused by moving objects. When a radar signal bounces off a moving target, the frequency of the reflected signal changes due to the Doppler effect. This filter processes these changes to isolate moving targets, even in situations where jamming is designed to blend moving and stationary objects. It is particularly useful in environments where high-speed objects (e.g., aircraft or ships) are involved.

Statistical and Adaptive Signal Processing (SASP) Enhanced Disturbance Filter

The SASP filter employs statistical and adaptive algorithms to detect deception jamming and filter out noise. Using techniques such as Savitzky-Golay and median filtering, SASP focuses on identifying patterns in noisy environments and distinguishing them from legitimate radar returns. By analyzing the statistical features of the radar signal, this filter adapts to changing conditions, ensuring continuous target tracking in a highly jammed or cluttered environment. SASP is particularly effective when dealing with multiple interference sources or dynamically changing environments, such as in air traffic control or maritime monitoring.

Simulating Real-World Scenarios

One of the strengths of SkySim’s EW extension is the ability to simulate real-world electronic warfare scenarios. By using the disturbance filtering tools, users can practice detecting and countering a wide range of jamming techniques. These scenarios can involve multiple targets, varying jamming powers, and different radar configurations, allowing users to explore the full spectrum of radar performance in contested environments.

For instance, an exercise may involve simulating spot jamming against a moving target, with the goal of detecting the target despite the interference. Users can adjust the jamming power, radar parameters, and disturbance filtering settings to see how these factors affect the radar’s ability to maintain target lock. Such simulations provide valuable insights into the practical challenges of electronic warfare.

The Role of SkySim in Electronic Warfare Training

SkySim’s electronic warfare extension, in combination with FreeScopes Disturbance Filtering & Analysis modules, provides a comprehensive environment for learning about radar jamming and countermeasures. These tools are essential for in military contexts. SkyRadar's solutions are available for military academies and military clients. They will require a clearance by the Luxemburgish Department of Defense.

Stay Tuned

Stay connected with our ongoing publications on SkySim and relevant qualification and learning solutions for ATSEP and military radar officers.