Lesson 11 Flashcards#
Click a question to reveal the answer.
1. How is the radar range equation "a target list" for EW?
Every factor is something one side attacks and the other defends: shrink \(\sigma\) (LO, EP), raise \(S_{\min}\) (noise jamming, EA), exploit \(G_t,G_r\) side lobes (EA), and collect the emitted \(P_t,\lambda,\) PRF (ES).
2. Define Electromagnetic Support (ES).
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.
3. Define Electromagnetic Protect (EP).
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.
4. Define Electromagnetic Attack (EA).
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").
5. One-sentence relationship among the three pillars?
ES senses, EP defends, EA attacks — and ES feeds the other two (attack needs cueing, protection needs to know what it faces).
6. Why does the listener detect at a longer range than the radar?
The radar's energy makes a round trip, so echo power falls as \(1/R^4\). The RWR hears a one-way transmission, falling as \(1/R^2\). Same emitter, same instant — the listener wins by orders of magnitude.
7. In practice, what limits an RWR's intercept range?
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.
8. Which EW lever attacks \(S_{\min}\), and how?
Noise jamming (EA). It injects energy into the threat receiver so the minimum detectable signal rises, shrinking the radar's effective detection range.
9. Which EW lever attacks the antenna gains, and how?
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.
10. State the move–countermove cycle of EW.
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.
11. Give a Block 1 example of the move–countermove cycle.
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.
12. What is the arc of Block 2?
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).