## Problem 217 — rank:247

**Title:** Wastewater-to-incidence calibration

**Added binding assumptions (LaTeX):**

```latex
Fix pre-window incidence and background initialization, the normalization of the measured signal and the error dependence across days. Kernel normalization removes one parameterization redundancy but does not identify the amplitude scale $a_tI_t$. A proposed minimum calibration design depends on the dimensions and separation of the admissible incidence, amplitude and delay families. Confidence claims require calibrated sets, not arbitrary residual-tolerance contours.
```

**Direct edits:** 0. **Fresh external checks:** None; supplied sources retained as provenance.