No new theory today. Your group is the B-21 mission-planning cell, and the period belongs to Project 2: geolocate the IADS emitters defending a target area — passively, from RWR bearings — precisely enough to cue a weapon, while the aircraft stays outside every threat's lethal range.
## The ask Produce **weapon-quality locations** for the emitters defending a target area, found passively from RWR bearings while the B-21 stays on a standoff orbit outside every threat ring. Everything you need is in L13–L14: angle of arrival, lines of position, and crossing bearings into a fix. A bearing is a line — the *fix, and its precision*, is the product. ## The scenario A notional IADS sector near the grid origin (km, North/East). The priors are coarse ELINT ($\pm 5$ km) — good enough to plan against, not to shoot: | 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 | Your entire flight path must stay **outside** all three keep-out circles. ## Bearings to a fix to an ellipse Each RWR cut is a bearing with noise $\sigma_\theta = 0.5^\circ$. Cross cuts taken from different points along your path and the lines meet at a fix — with an **error ellipse** set by geometry and noise. A wide cut and a long baseline shrink the ellipse; a 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. ## The spec — and the tension The standoff weapon's seeker acquires within a 1 km basket, so to cue it confidently you need $$ \mathrm{CEP} \le \tfrac{1}{2}(1\ \text{km}) = 0.5\ \text{km} $$ for the lethal emitters (ACQ and TTR at least). **Accuracy** wants you close and on a long baseline; **survivability** wants you far, outside every keep-out. The whole project lives in that tension — defend your geometry. ## Your tasks 1. **Geolocation pipeline** — bearings to a fix to a $1\sigma$ ellipse; verify on the starter. 2. **Collection design** — choose standoff, baseline, heading, and 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, and ellipses, to scale. 6. **Recommendation** — one slide to the strike cell. ## Materials Project 2 handout (PDF) IADS_Scenario.csv MATLAB · code/L19_Project2Starter.m↓ The starter reads `IADS_Scenario.csv`, flies a two-waypoint sample leg, calls `rwr_collection_sim.m` to collect noisy bearings, and cross-fixes one emitter with its $1\sigma$ ellipse and CEP. The true emitter positions are hidden inside the simulator — estimating them is the job. **Verify the two-point case first, then add cuts, emitters, and geometry.** (The simulator and CSV are bundled in the code zip beside the starter, which reads them from the current folder.) ## How to use the work day - **First 10 minutes** — groups assigned; read the handout together and sketch the geometry. - **Next 30 minutes** — divide the work: pipeline, collection design, execution, visualization, story. - **Last 10 minutes** — regroup: what's done, what's blocked, who owns what before L20. Plan the presentation first — it tells you what to compute. Next lesson: **L20 — Project 2 presentations.** Slides and code due before class, HW2 due at the start of class, and Quiz 2 in class.