ECE 495 — Electromagnetic Warfare and Survivability
Block 2: RF Electronic Warfare
Lesson 19: Project 2 Work Day
Lesson 19: Project 2 Work Day
Juan Jurado, Col, USAF, Ph.D.
Permanent Professor and Head
Electrical and Computer Engineering
Fall 2026
Permanent Professor and Head
Electrical and Computer Engineering
Fall 2026
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Block 2 · Lesson 19 · The Ask
Project 2: The Ask
Your group is the B-21 mission-planning cell.
Product
Weapon-quality locations for the IADS emitters defending a target area — found passively, from RWR bearings, while the aircraft stays outside every threat's lethal range.
- Everything you need is in L13–L14: AoA, lines of position, crossing into a fix
- Handout, scenario CSV, collection simulator, and starter are posted
- Results presentations at L20 — 10 minutes, 5 of Q&A, everyone speaks
A bearing is a line. The fix — and its precision — is the product.
Block 2 · Lesson 19 · Scenario
The Scenario: Three Emitters, Three Keep-Outs
A notional IADS sector near the grid origin (km, North/East).
E1 · EW
E2 · ACQ
E3 · TTR
scale: 55 px = 10 km · circles are keep-out radii
| ID | Class | Band | Prior (N, E) | Keep-out |
|---|---|---|---|---|
| E1 | EW | UHF (0.5 GHz) | (0, 0) | 20 km |
| E2 | ACQ | S (3 GHz) | (10, −8) | 45 km |
| E3 | TTR | X (10 GHz) | (−6, 6) | 40 km |
- Positions are coarse ELINT priors (±5 km) — good enough to plan, not to shoot
- Your entire flight path must stay outside all three keep-out circles
Block 2 · Lesson 19 · Method
Bearings to a Fix to an Ellipse
Each RWR cut is a bearing with noise $\sigma_\theta = 0.5^\circ$. Cross cuts from different points and the lines meet at a fix — with an error ellipse.
The ellipse comes from geometry and noise
$$\mathbf{C} = \left[\frac{1}{\sigma_\theta^{2}}\sum_{k}\mathbf{H}_k^{\top}\mathbf{H}_k\right]^{-1}$$
- Wide cut and long baseline shrink it; shallow cut or long range stretch it
- Summarize each fix by its $\mathrm{CEP} \approx 0.59(a+b)$ from the $1\sigma$ semi-axes
This is L14 made operational: geometry, not receiver quality, sets your accuracy.
Block 2 · Lesson 19 · The Spec
The Spec — and the Tension
The standoff weapon's terminal seeker acquires the emitter once it is within an acquisition basket of radius 1 km of the cued aimpoint.
To acquire with high confidence, the cued location error has to sit well inside that basket — so the fix, not the seeker, is what has to be good.
Cueing specification
$$\mathrm{CEP} \;\le\; \tfrac{1}{2}\,(1\ \text{km}) \;=\; 0.5\ \text{km}$$
Meet it for the lethal emitters — the ACQ and the TTR at least.
Block 2 · Lesson 19 · The Spec
The Spec — and the Tension
Cueing specification
$$\mathrm{CEP} \;\le\; \tfrac{1}{2}\,(1\ \text{km}) \;=\; 0.5\ \text{km}$$
Accuracy wants
You close, and on a long baseline.
Short range and a wide cut angle are what shrink the ellipse — and both of them pull you toward the threat.
Short range and a wide cut angle are what shrink the ellipse — and both of them pull you toward the threat.
Survivability wants
You far — outside every keep-out.
Not at the closest point of approach: the whole flight path, for the whole collection.
Not at the closest point of approach: the whole flight path, for the whole collection.
The whole project lives in that tension. Defend your geometry.
Block 2 · Lesson 19 · Tasking
Your Tasks
- 1 · Geolocation pipeline — bearings to a fix to a $1\sigma$ ellipse; verify on the starter
- 2 · Collection design — standoff, baseline, heading, cuts; stay outside every keep-out
- 3 · Execute and geolocate — run the simulator along your path; report fixes and CEP
- 4 · Meet the spec — who passes, who doesn't, and the accuracy–standoff trade
- 5 · Visualization — emitters, keep-outs, path, fixes, ellipses, to scale
- 6 · Recommendation — one slide to the strike cell
Block 2 · Lesson 19 · Starter
Starting Point
The starter gives you a working pipeline for the simplest case:
- Reads
IADS_Scenario.csvand flies a three-waypoint sample leg - Calls
rwr_collection_sim.pto collect noisy bearings - Fixes one emitter by least squares (its
lsq_fixhelper) and draws its $1\sigma$ ellipse with CEP
Example File: L19_Project2Starter.m
The true emitter positions are hidden in the simulator — estimate them. Verify the two-point case, then add cuts, emitters, and geometry.
Block 2 · Lesson 19 · Battle Rhythm
Today's Battle Rhythm
| Clock | What happens |
|---|---|
| First 10 min | Groups assigned, claim a whiteboard, read the handout together |
| Next 30 min | Divide the work: pipeline, geometry design, visualization, story |
| Last 10 min | Regroup: what's done, what's blocked, who owns what before L20 |
I am floating between groups — pitch me your collection geometry early.
Sketch the geometry before you write code — it tells you what to fly.
Block 2 · Lesson 19 · Wrap-Up
Wrap-Up
Before you leave
- Pipeline verified against the starter's three-cut fix
- A first collection geometry sketched — and checked against the keep-outs
- Task owners assigned through L20
Next lesson
- L20: Project 2 results presentations — slides and code due before class
- HW2 due at the start of L20
- Quiz 2 (open book) in class, tied to your project work