# Lesson 24 — IR Countermeasures

<p class="block-synopsis">L23 built the infrared seeker; this lesson fights it. Every countermeasure is a move against the seeker's <em>information</em> — starve the track, clutter it, deceive it, or damage it — and every move is answered, from the flare to the IRCCM cue triad to the DIRCM laser. That move–countermove duel is the whole lesson.</p>

<div class="block-toc">
  <a class="bt-card bt-reading" href="L24_IRCountermeasures_Reading.html">
    <span class="bt-kind">Reading</span>
    <h4>IR Countermeasures</h4>
    <p>The four ways to attack the optical track, the flare seduction contest, the IRCCM cue triad that rejects flares, and why Band IV pushed CM toward DIRCM and signature suppression.</p>
  </a>
  <a class="bt-card bt-flashcards" href="L24_Flashcards.html">
    <span class="bt-kind">Flashcards</span>
    <h4>Review deck</h4>
    <p>Key terms and relations from the lesson, in a self-test deck.</p>
  </a>
  <a class="bt-card bt-preflight" href="L24_Preflight.html">
    <span class="bt-kind">Pre-flight</span>
    <h4>Pre-flight quiz</h4>
    <p>Five questions to work before class — anyone can be called to the board.</p>
  </a>
  <a class="bt-card bt-slides" href="../_static/slides/ECE%20495%20-%20EW%20and%20Survivability%20-%20B3L24%20-%20Fall%202026.pdf" target="_blank" rel="noopener">
    <span class="bt-kind">Slides</span>
    <h4>Lesson slides</h4>
    <p>The deck we work through in class, as a PDF you can annotate.</p>
  </a>
  <a class="bt-card bt-demo" href="L24_SeekerBench_Demo.html">
    <span class="bt-kind">Demo</span>
    <h4>Seeker Bench</h4>
    <p>Drive the flare's peak intensity and rise time and watch the seduction window open when J_flare > J_tgt and slam shut when the pair splits the gate.</p>
  </a>
</div>
