# Lesson 11 Flashcards

Click a question to reveal the answer.

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<summary><strong>1. How is the radar range equation "a target list" for EW?</strong></summary>
<div class="card-answer"><p>Every factor is something one side attacks and the other defends: shrink <span class="math notranslate nohighlight">\(\sigma\)</span> (LO, EP), raise <span class="math notranslate nohighlight">\(S_{\min}\)</span> (noise jamming, EA), exploit <span class="math notranslate nohighlight">\(G_t,G_r\)</span> side lobes (EA), and collect the emitted <span class="math notranslate nohighlight">\(P_t,\lambda,\)</span> PRF (ES).</p></div>
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<summary><strong>2. Define Electromagnetic Support (ES).</strong></summary>
<div class="card-answer"><p>Sensing the spectrum to support targeting, warning, and intelligence — RWRs on-board, SIGINT/ELINT off-board. It exploits the radar's one unavoidable weakness (it must radiate) and feeds EA and route planning. Legacy term: ESM.</p></div>
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<summary><strong>3. Define Electromagnetic Protect (EP).</strong></summary>
<div class="card-answer"><p>Defending our own use of the spectrum from enemy attack and friendly interference: LPI waveforms, frequency/polarization agility, side-lobe cancellation, hardening, and LO. Legacy term: ECCM.</p></div>
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<summary><strong>4. Define Electromagnetic Attack (EA).</strong></summary>
<div class="card-answer"><p>Denying, degrading, or deceiving the enemy's use of the spectrum: noise jamming, DRFM deception, expendables (chaff/flares), and counter-PNT. Legacy terms: ECM (and, confusingly, "EW").</p></div>
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<summary><strong>5. One-sentence relationship among the three pillars?</strong></summary>
<div class="card-answer"><p>ES senses, EP defends, EA attacks — and ES feeds the other two (attack needs cueing, protection needs to know what it faces).</p></div>
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<summary><strong>6. Why does the listener detect at a longer range than the radar?</strong></summary>
<div class="card-answer"><p>The radar's energy makes a round trip, so echo power falls as <span class="math notranslate nohighlight">\(1/R^4\)</span>. The RWR hears a one-way transmission, falling as <span class="math notranslate nohighlight">\(1/R^2\)</span>. Same emitter, same instant — the listener wins by orders of magnitude.</p></div>
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<summary><strong>7. In practice, what limits an RWR's intercept range?</strong></summary>
<div class="card-answer"><p>The radio horizon (a few hundred km at altitude), not its sensitivity. The listener's detection problem is solved by geometry; the radar's is bounded by the fourth-power law it cannot escape.</p></div>
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<summary><strong>8. Which EW lever attacks <span class="math notranslate nohighlight">\(S_{\min}\)</span>, and how?</strong></summary>
<div class="card-answer"><p>Noise jamming (EA). It injects energy into the threat receiver so the minimum <em>detectable</em> signal rises, shrinking the radar's effective detection range.</p></div>
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<summary><strong>9. Which EW lever attacks the antenna gains, and how?</strong></summary>
<div class="card-answer"><p>EA enters through the side lobes (L6) that every antenna has — energy injected off the main beam still reaches the receiver. EP answers with side-lobe cancellation and low-SLL design.</p></div>
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<summary><strong>10. State the move–countermove cycle of EW.</strong></summary>
<div class="card-answer"><p>Action (radar innovates: pulse-Doppler, agility, LPI) → reaction (jammers, chaff, DRFM, LO) → counter-reaction (hopping, side-lobe cancellation, adaptive processing, multistatic). No move is permanent.</p></div>
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<summary><strong>11. Give a Block 1 example of the move–countermove cycle.</strong></summary>
<div class="card-answer"><p>MTI / pulse-Doppler answered chaff and clutter; low-band early-warning radars answer LO. Each Block 1 technique was itself a move in the EW game.</p></div>
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<summary><strong>12. What is the arc of Block 2?</strong></summary>
<div class="card-answer"><p>ES (L12–L14: RWR, AoA, triangulation) → EP (L15–L16: LPI, agility, spread spectrum) → EA (L17–L18: jamming, J/S, DRFM) → Project 2 (L19–L20: standoff geolocation).</p></div>
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