Electronic Warfare Notes

Electronic Warfare

Electronic Warfare (EW) involves actions across the electromagnetic spectrum to intercept, analyze, manipulate, or suppress enemy use of the spectrum, while protecting friendly use from similar attacks.

Three Main Components of Electronic Warfare:

  • Electronic Support (ES):
    • Passive surveillance of the EM spectrum.
    • Includes signal intelligence (SIGINT) and direction finding.
  • Electronic Attack (EA):
    • Offensive operations.
    • Techniques: Jamming, deception, use of expendables, or stealth.
  • Electronic Protection (EP):
    • Defensive actions.
    • Protects friendly use of the spectrum.
    • Examples: Encryption and anti-jamming.

Electromagnetic Spectrum

The electromagnetic spectrum is the range of all electromagnetic radiation, categorized by wavelength and frequency. It includes:

  • Radio Waves
    • Used in broadcasting, communication systems, and radar.
    • Possess the longest wavelengths.
  • Microwaves
    • Useful for radar systems, satellite communications, and cooking.
  • Infrared Radiation
    • Transmits heat.
    • Applications: Night vision, remote sensing, and heating.
  • Visible Light
    • The only part of the spectrum that is visible to the human eye.
    • Allows us to perceive color and light.
  • Ultraviolet
    • Found in sunlight; can cause skin burns.
    • Used in disinfection and fluorescent lights.
  • X-rays
    • Penetrate materials.
    • Used in medical imaging.
  • Gamma Rays
    • Most energetic with the shortest wavelengths.
    • Applications: cancer treatment; emitted during nuclear reactions.
  • In EW, the radio and microwave segments are of highest operational interest.

Electronic Support (ES)

ES involves passive collection of EM emissions to provide situational awareness and early warning.

  • Examples:
    • EA-18G Growler
    • EP-3
    • UAVs
    • Satellites
    • SLQ-32
  • ELINT: Information derived from radar emissions.
  • COMINT: Information derived from communications.

Electronic Attack (EA)

EA seeks to degrade, disrupt, or destroy enemy capability to use the EM spectrum. Methods include:

  1. Jamming (Denial and Deception)

    • Jamming Techniques
      • Denial Jamming: Masks target using noise (spot, barrage, swept-spot).
        • Spot Jamming: Focuses energy on a single frequency.
        • Barrage Jamming: Spreads energy across multiple frequencies.
        • Swept-Spot Jamming: Rapidly sweeps energy across a range.
      • Burn-through: The point where radar power exceeds jamming and regains visibility.
      • Look-through: Momentary pauses in jamming to gather information or reassess.
      • Deception Jamming: Sends false signals to confuse radar (angle/range deception).
        • Range Deception: Confuses distance measurements.
        • Angle Deception: Misleads direction-finding.
    • Jamming Tactics
      • Stand-off Jamming: From afar, safer but weaker.
      • Self/Escort Jamming: Close proximity, strong but riskier.
      • Stand-in Jamming: Unmanned platforms conduct jamming at close range.
      • Denial hides you; deception fools the enemy. Tactics vary based on mission risk and objective.

  2. Expendables: Disposable defense systems deployed by aircraft to confuse or divert incoming threats like missiles.

    • Chaff – Radar Countermeasure
      • Made of aluminum-coated fiberglass or metallic strips.
      • Released into the air to reflect radar signals, creating a larger Radar Cross Section (RCS) than the aircraft.
      • Confuses radar-guided missiles by making the chaff cloud look like the real target.
    • Flare – Infrared Countermeasure
      • Emits intense infrared (IR) radiation to mimic the heat signature of an aircraft engine.
      • Used to divert heat-seeking missiles away from the actual aircraft.
      • Typically chemical-based and burns hotter than the aircraft exhaust.
    • Decoys – Electronic Countermeasure
      • Use transmitters that simulate radar signals or aircraft signatures.
      • Designed to deceive enemy radar systems by creating false targets or redirecting missile guidance.
      • Can be towed or deployed remotely.

  3. Stealth and radar cross-section reduction

    • Involves reducing an object’s radar signature through shape, size, and material—making it harder to detect.
    • Stealth refers to design techniques and technologies used to make military assets like ships and aircraft less detectable by radar. One of the most critical factors is the shape of the target, which affects how radar waves reflect off its surfaces.
    • RCS measures how detectable an object is to radar. A smaller RCS means the object reflects less radar energy, making it harder to detect.
      • MASS
        • Material: Radar-absorbing materials reduce reflections.
        • Aspect: The direction the radar views the object (head-on, side, etc.) affects how much signal is returned.
        • Size: Larger objects generally reflect more radar energy.
        • Shape: Angular or faceted designs deflect radar away from the receiver (e.g., the sharp angles on the ship and aircraft shown).
    • Stealth technology reduces an object’s Radar Cross Section (RCS) using clever design and materials, helping it avoid detection by enemy radar systems.

  4. Hard-kill via EM-guided munitions (Home-on-Emitter)

    • A destructive method using EM- guided weapons to physically destroy enemy emitters. This guidance system locks onto and follows the signal of a radar emitter — typically a hostile ground-based or airborne radar. The missile uses this radar signal to guide itself directly to the source. This is commonly used for Suppression of Enemy Air Defenses (SEAD) missions.
      • Example: AGM-88 HARM (High-speed Anti-Radiation Missile)
    • Home-On-Jam (HOJ): Seeks out the source of jamming signals. This guidance allows the missile to follow jamming signals instead of radar emissions. If the enemy tries to jam radar to avoid detection or missile lock, the missile can actually use that jamming as a guidance source — turning the enemy's defensive jamming into a vulnerability.

EA ranges from non-lethal interference (soft-kill) to physical destruction (hard-kill), all aimed at denying the enemy effective use of the EM spectrum.

Electronic Protection (EP)

EP ensures continued friendly use of the EM spectrum by mitigating EA. Techniques:

  • Encryption and frequency hopping
  • Anti-jamming filters and power control