# Study 01 — Sensitivity Map (Method D)

**Type:** Parametric — Prescribed Unit Displacements
**Runs:** 12 (9 unique @ 60° + 1 baseline + 2 spot checks @ 40°)
**Model:** Enforced displacement BCs with expression control

## What This Does

Applies +1 μm displacement at each unique interface point in each global DOF direction, one at a time. Measures ΔWFE to build a sensitivity matrix: **nm WFE per μm displacement per DOF per point.**

This is the PRIMARY deliverable for StarSpec.

## .sim Setup Required

1. Create 9 NX expressions: `dV1_X, dV1_Y, dV1_Z, dV2_X, dV2_Y, dV2_Z, dL1_X, dL1_Y, dL1_Z` (all default = 0)
2. Apply enforced displacement BCs on all 5 support nodes referencing these expressions
3. Symmetry ties: V_right X = −dV2_X, L_right X = −dL1_X; Y/Z same sign as left counterpart
4. Gravity load at target elevation (60° or 40°)

## Extractor

Zernike annular OPD: 50 modes, J5+ filtered, inner_radius = 135.75 mm, reference subcase = 20° elevation.

**Also extract individually:** J9, J10 (trefoil) and J11 (spherical) for secondary reporting.

## Output

Sensitivity matrix → feed into displacement limits and StarSpec deliverable.