L12 Pre-flight

L12 Pre-flight#

Block 2: RF Electronic Warfare — Lesson 12: Electromagnetic Support Work this before L12. Pre-flights are never collected — in class, anyone may be cold-called to present any question at the board, and that recitation is the participation grade.

Assumed pre-class reading#

  • L11 wrap-up

  • The Jupyter Book Reading page for L12 — ES vs ELINT, the four threat-warning functions, the RWR block diagram, and pulse descriptor words.

Quiz questions (5 items, ~5 minutes)#

Q1. (Multiple choice) The key difference between ES and ELINT is:

  • [ ] (a) ES is flown on tactical aircraft; ELINT is collected only from fixed ground sites

  • [ ] (b) ES collects enough to name the type and mode now; ELINT collects full depth

  • [ ] (c) ES measures pulse parameters; ELINT measures optical and infrared signatures

  • [ ] (d) ES and ELINT collect the same data; only the reporting timeline differs

Q2. (Multiple choice) The four basic functions of every threat warning system, in order, are:

  • [ ] (a) Search, Acquire, Track, Engage

  • [ ] (b) Observe, Detect, Classify, Alert

  • [ ] (c) Detect, Jam, Deceive, Evade

  • [ ] (d) Monitor, Record, Analyze, Disseminate

Q3. (Multiple choice) An RWR must monitor tens of GHz of spectrum at once. The price of that bandwidth is:

  • [ ] (a) Nothing — bandwidth is free in a receive-only system, since nothing is radiated

  • [ ] (b) A higher thermal noise floor, \(N = kTB\), and so reduced sensitivity

  • [ ] (c) Antennas long enough to resonate across every band covered

  • [ ] (d) A transmitter powerful enough to cover the same bandwidth

Q4. (Short answer) An RWR builds its pulse descriptor word as pulses arrive. Sort these five parameters by how many pulses each one needs — carrier frequency, pulse width, angle of arrival, PRI, antenna scan rate — and say why the last one cannot be hurried.

Q5. (Multiple choice) Your RWR scope goes completely quiet mid-ingress. The safest interpretation is:

  • [ ] (a) Every emitter that was tracking you has been destroyed by the strike

  • [ ] (b) The aircraft is undetectable for as long as the scope stays quiet

  • [ ] (c) Nothing that radiates in RF is currently illuminating you

  • [ ] (d) The RWR has failed and should be assumed unreliable

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