Lesson 7 Flashcards#
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1. In one sentence, what is an IADS?
A layered, integrated air-defense system: a cascade of specialized radars, each doing one job and handing its track to the next, that together cover the engagement.
2. What does an Early Warning (EW) radar do, and in what band?
Detects inbound air activity at hundreds of km and alerts higher echelons. UHF or L band, large antenna, low PRF, wide fan beam on a slow rotation (2D track only).
3. What is the job of the ACQ and HF radars?
Acquisition (ACQ) produces 3D tracks for engagement (typically S band); a height-finder (HF) adds elevation to a 2D ACQ. Together they hand a 3D track to the engagement radars.
4. What does GCI provide?
Ground-controlled intercept — the C2 layer that vectors interceptor aircraft using the IADS's 3D track picture.
5. TTR vs TIR — what is the difference?
The target-tracking radar (TTR) is the SAM site's fire-control sensor holding the target. The target-illuminating radar (TIR) floods the target with energy so a semi-active missile seeker can home on the reflection.
6. What band and PRF characterize a TTR?
X band, narrow slewable pencil beam, medium-to-high PRF (often pulse-Doppler), at tens to a low hundred km.
7. What sensors operate in the terminal layer?
The AI (airborne interceptor) radar — X-band AESA fighter fire control; the missile's active seeker — Ka/mmW, very high PRF over the last 5–20 km; and the proximity fuse — short-range CW/high-PRF that triggers the warhead at burst radius.
8. Match the kill-chain links to radar classes.
Detect → EW; Track/Identify → ACQ+HF, GCI, ESM; Engage (cue) → TTR/AI; Engage (illuminate) → TIR; Engage (terminal) → active seeker; Kill → proximity fuse.
9. Why do EW investments tend to attack the early kill-chain rows?
The early rows (Detect, Track) are cheaper to defeat and have higher payoff — everything downstream depends on them, so breaking a handoff early starves the whole chain.
10. How does a B-21-class target (≈ −30 dBsm) change detection range?
Because \(R_{\max}\propto\sigma^{1/4}\), a \(-30\) dBsm RCS collapses detection range to about 17.8% of the legacy (1 m²) value at every layer.
11. Where does LO buy the most absolute kilometers, and why?
At the EW and ACQ layers. The percentage reduction is the same everywhere (\(\sigma^{1/4}\)), so the largest raw shrink happens where the rings start largest — the long-range surveillance layers.
12. Does LO make the bomber invulnerable?
No. It shrinks every ring proportionally; the engagement layers still close in. LO buys standoff and time, not invisibility — which is why later blocks add active EW on top.