USAFA DFEC

ECE 495 — Electromagnetic Warfare and Survivability

Block 1: Radar Fundamentals
Lesson 1: Introduction
Juan Jurado, Col, USAF, Ph.D.
Permanent Professor and Head
Electrical and Computer Engineering
Fall 2026
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Block 1 · Lesson 1 · Welcome

Welcome to ECE 495 - EW

This course studies how modern aircraft survive in contested airspace.

  • Radar physics, RF electronic warfare, infrared warfare, signature management, and integrated mission planning
  • Centered on a single operational thread: the B-21 Raider
  • Class style: short lectures, Socratic discussion, in-class interactive demos, group results presentations
If the aircraft can be killed, none of the rest of the avionics matters.

Block 1 · Lesson 1 · Objectives

Lesson Objectives

By the end of this lesson, you will be able to:

  • Place this course in the broader EW and survivability landscape
  • Describe the threat kill chain and identify where each survivability discipline acts
  • Explain the ES / EP / EA framework and classify common tactics
  • State the fourth-power law and why large RCS cuts buy modest range cuts
  • Recognize how the four Blocks of this course build toward integrated survivability

Block 1 · Lesson 1 · Course Roadmap

Course Roadmap: Four Blocks, 41 Lessons

Four blocks, each one building the tools the next block spends.

Block 1
→
Block 2
→
Block 3
→
Block 4

Block 1 · Lesson 1 · Course Roadmap

Course Roadmap: Four Blocks, 41 Lessons

Block 1
Radar
Fundamentals
→
Block 2
RF Electronic
Warfare
→
Block 3
IR EW and
Signatures
→
Block 4
Survivability and
Mission Planning
  • B1–B3 each end with an individual homework, a group project + presentation, and a project quiz
  • B4 closes with the individual Final Project — in lieu of a final exam
  • Pre-flight worked before every class — you present yours at the board 2–3 times
  • Today we set the stage; the rest of B1 builds the radar physics you need

Block 1 · Lesson 1 · Operational Thread

Operational Thread: The B-21 Raider

  • Long-range penetrating strike bomber
  • All-aspect, broadband low observability — a defining design choice
  • Mission profile stresses every survivability discipline at once:
    • Detection avoidance across radar bands and aspects
    • Passive RF cueing against fielded IADS
    • IR signature management against modern seekers
    • Long-route planning under layered threats
The thread
Every project this semester is a B-21 scenario. The platform is the thread that ties the math back to a real mission.

Block 1 · Lesson 1 · Part One

The Kill Chain

Five links, in order. The whole course is an argument about which one to break.

Block 1 · Lesson 1 · The Kill Chain

The Air Threat Kill Chain

Detectfind it
→
Trackhold it
→
Identifyname it
→
Engagecommit it
→
Killthe outcome
  • Every kill requires that the threat complete every link in sequence
  • Break any one link and the aircraft survives
  • This is the organizing principle for the entire course
Survivability is breaking the chain before it breaks you.

Block 1 · Lesson 1 · Breaking the Chain

Who Breaks Which Link?

Detectfind it
→
Trackhold it
→
Identifyname it
→
Engagecommit it
→
Killthe outcome
LO · EMCON · signatures
noise jamming (EA)
EW deception
and protection
ES · EP · EA
across the track
Tactics · maneuver
decoys · CM
Hardening
redundancy
  • Detect — B2 brings the jamming; B3 and B4 build the signature side
  • Track / Identify — B2 builds the RF side; B3 adds IR
  • Engage — Block 4 brings it together
  • Kill — out of scope here, but worth knowing it exists
Every link broken is a kill prevented.

Block 1 · Lesson 1 · Part Two

Electromagnetic S / P / A

Support listens. Protect defends. Attack denies. Every technique in this course is one of the three.

Block 1 · Lesson 1 · The EW Framework

Electromagnetic Warfare: ES / EP / EA

Goal of EW: control the EM spectrum for our use, deny it to the enemy.
ES — Electromagnetic Support
Situational awareness. Know what is emitting, where, and what it is.
Examples: Radar Warning Receiver (RWR), ELINT.
EP — Electromagnetic Protect
Protect our use of spectrum. Make our radios and radars resistant to the threat.
Examples: LPI waveforms, frequency hopping, EMCON.
EA — Electromagnetic Attack
Deny enemy use of spectrum. Jam, deceive, or destroy threat sensors.
Examples: noise jamming, DRFM, chaff, towed decoys.
listens
defends
attacks
“Electronic” is the legacy term; “Electromagnetic” is the current Joint term.

Block 1 · Lesson 1 · The Problem

Why EW Is Hard

  • Everyone is a player. Friendly, neutral, and adversary systems all touch the same spectrum
  • Crowded and contested. Wideband, dense, shared use; commercial overlay
  • Multi- and hyper-spectral. Many bands active at once, often beyond a single receiver's BW
  • Information-rich. Massive data flows; constant emissions are also constant opportunities
  • Extremely dynamic. Move and counter-move on tactical timescales — chess with strategy, tactics, and adaptation
EW is decided as much by speed of adaptation as by hardware.

Block 1 · Lesson 1 · Type-along

Your Turn

Laptops open, MATLAB up. Twelve lines, typed together.

Block 1 · Lesson 1 · Quick Exercise

Quick Exercise / Type-along: dB in Your Head

Open MATLAB. Type this with me — twelve lines, no toolboxes.

% L1 type-along -- dB is a language for ratios
clear; clc
ratios = [2 4 16 1000];           % power ratios worth memorizing
dB     = 10*log10(ratios);        % ratio -> dB
for k = 1:numel(ratios)
    fprintf('x%-5g = %6.2f dB\n', ratios(k), dB(k));
end
rcs_cut_dB   = -12;               % the B-21 shaves 12 dB off its RCS
range_dB     = rcs_cut_dB/4;      % fourth-power law: R ~ sigma^(1/4)
range_factor = 10^(range_dB/10);  % dB -> plain ratio
fprintf('RCS %+d dB -> range %+.1f dB -> R_max x %.3f\n', ...
        rcs_cut_dB, range_dB, range_factor);

What do you notice?

Twelve dB of RCS came out the other side as three dB of range — and three dB is the first number in your table.

Block 1 · Lesson 1 · Mechanics

How This Course Works

  • Pre-flight worked before every class
    • A short problem set on the lesson — do it before you walk in
    • Called at random 2–3 times a semester to present yours
    • That recitation is the 10% participation grade
  • In class — short lecture, Socratic discussion, in-class interactive demos
    • Bring a laptop with MATLAB
  • B1–B3: individual homework, group project, individual project quiz
    • Projects end with a group results presentation — innovation bonus available
    • B4 swaps the group project for the individual Final Project
  • Out of class: online companion book with reading, flashcards, and interactive demos

Block 1 · Lesson 1 · Grading

Grading Snapshot

CategoryWeight
Group Projects (B1–B3)30%
Final Project — individual, in lieu of a final exam20%
Individual Homeworks20%
Individual Project Quizzes20%
Participation (pre-flight board recitation)10%
Total100%
  • Homework: binary rubric (1 / 0); one resubmission per question
  • Projects: category rubric; innovation bonus available; no regrades
  • Project quizzes: open book, 15 min, related to project work and topics
  • Participation: graded on the pre-flight you present, not on attendance

Today's Interactive Demo: Kill Chain Explorer

Companion script: L1_FourthPowerLaw.m
plots $R_{\max} \propto \sigma^{1/4}$ across a 60 dB RCS range
Live demo

Kill Chain Explorer

usafa-ece.github.io/ece-495-ew

Block 1 · Lesson 1 · Wrap-Up

Wrap-Up

Key ideas
  • Survivability = breaking the kill chain (Detect, Track, Identify, Engage, Kill)
  • EW operates in three pillars: ES (sense), EP (protect), EA (attack)
  • Four Blocks, three group projects, an individual Final Project capstone
Next lesson
  • L2: EM spectrum, propagation, polarization, and antenna basics
  • Work the L2 pre-flight before class — you could be the one up front