docs/PICKING_GUIDE.md

Quick 10-Line QGIS Ground-Truth Point Picking Guide

1. Open Project: Launch QGIS and double-click data/qgis_picking.qgz to load rasters and overlap grid.
2. Target Area: Pick points only inside the red outline (42% overlap region) across center and corners.
3. Target Count & Spacing: Aim for 25 points total, with at least 1 point per $30\text{ m}$ grid cell.
4. What to Click: Choose sharp crater rim crests, bright boulder clusters, small crater centers, or crisp ridge crests.
5. What to Avoid: Never click shadow interiors, feature-less mare, features $< 5\text{ px}$, or anything near frame edges.
6. Two-Pass Picking: Pick every physical feature TWICE — once on Reference layer, once on Registered Product layer.
7. Export CSV 1: Select Reference layer $\rightarrow$ Export Features As $\rightarrow$ CSV as data/heldout_ref.csv.
8. Export CSV 2: Select Registered Product layer $\rightarrow$ Export Features As $\rightarrow$ CSV as data/heldout_prod.csv.
9. Row Pairing Rule: Ensure Row $N$ in heldout_ref.csv corresponds to the exact same feature as Row $N$ in heldout_prod.csv.
10. Attribute Fields: Assign confidence (1=Certain, 2=Pretty Sure, 3=Best Guess) and feature_type (crater_rim/boulder/crater_center/ridge).