L29 Pre-flight

L29 Pre-flight#

Block 3: IR EW and Signature Management — Lesson 29: Project 3 Work Day Work this before L29. 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#

  • The Project 3 handout (B-21 IR/RCS Signature Trade Study), posted with B21_SignaturePattern.csv, SignatureMenu.csv, and L29_Project3Starter.m.

  • The L28 wrap-up (the loudest-band fusion rule).

This quiz checks that you arrive ready to work, not that you have done the project. Read the handout and skim the starter before class.

Quiz questions (5 items, ~5 minutes)#

Q1. (Multiple choice) In Project 3, the product your group must deliver is:

  • [ ] (a) A single new stealth coating that beats every threat

  • [ ] (b) A prioritized package of signature investments, chosen within a fixed budget, that minimizes the aircraft’s detection range

  • [ ] (c) A flight route that avoids all three threats

  • [ ] (d) The exact RCS of the B-21 at every aspect

Q2. (Multiple choice) Detection across the three threats obeys the loudest-band rule \(R_{\text{det}} = \max_b R_b\). To reduce \(R_{\text{det}}\), an investment must:

  • [ ] (a) Reduce any band at all — they all help equally

  • [ ] (b) Reduce the band that is currently the limiter (the longest-range threat)

  • [ ] (c) Reduce the quietest band first

  • [ ] (d) Increase the aircraft’s speed

Q3. (Multiple choice) The scenario has three threats: a VHF surveillance radar, an X-band fire-control radar, and an IR MANPADS. At the baseline signature, which one is the loudest band (sets \(R_{\text{det}}\))?

  • [ ] (a) The IR MANPADS, because IR is always the hardest to hide

  • [ ] (b) The VHF surveillance radar, at about 90 km — and shaping/RAM barely help at VHF

  • [ ] (c) The X-band fire-control radar, at about 45 km

  • [ ] (d) They are all equal at baseline

Q4. (Short answer) Project 3 has a built-in budget tension. In one or two sentences, explain why you cannot simply buy the cheapest signature treatments and why the loudest threat is hard to address.

Q5. (Multiple choice) The starter script L29_Project3Starter.m:

  • [ ] (a) Already contains the optimal package — just read it off

  • [ ] (b) Scores one example package (X-band RAM + plume) that leaves you found at ~85 km, so you must design a better package within the same budget

  • [ ] (c) Computes nothing; it is only a plotting template

  • [ ] (d) Requires the true threat positions, which are hidden

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