 Response-normalized tolerance for baseline-feasibility residuals

A response-normalized tolerance for baseline-feasibility residuals measures a pulse estimator's constraint errors against physically chosen response limits. For residual $\mathbf{r}=F^T\hat{\mathbf{a}}-\mathbf{b}$, assign positive tolerances ${\delta }_j$ in the corresponding response units and calculateThe criterion $\eta \le 1$ means every specified response limit is satisfied. Numerical feasibility residual for baseline constraints explains why a raw unscaled norm alone has no universal physical interpretation.

These tolerances can enforce a deterministic bias budget. If signal and background coefficients are bounded by $|\theta |\le B_s$ and $|{\beta }_j|\le B_j$, thenThe second inequality follows when the normalized test passes. The allocation of a deterministic bias budget among baseline constraints therefore connects a numerical acceptance criterion to a stated physical error allowance.

For an original example, bound the signal amplitude by $1\mathrm{mV}$, constant background by $20\mathrm{mV}$ and drift rate by $100V/s$. Choose signal-response tolerance $2\times 10^{-6}$, constant-response tolerance $2\times 10^{-7}$ and linear-time-response tolerance $4\times 10^{-11}\mathrm{s}$. Their maximum bias contributions are respectively $2$, $4$ and $4\mathrm{nV}$, totaling $10\mathrm{nV}$. If all actual residuals are half these tolerances, $\eta =0.5$ and the corresponding bias bound is $5\mathrm{nV}$.

The normalized test can be invariant to constraint units. Multiplying one equation and its required response by a nonzero factor $q_j$ multiplies its residual by $q_j$; replacing its tolerance by $|q_j|{\delta }_j$ keeps the ratio unchanged. The associated coefficient bound changes inversely, so the physical product $B_j{\delta }_j$ is unchanged as well.

NIST's before/after pulse baselines supply a measurement setting where residual offset and drift responses matter.^[ref] The example bounds and tolerances are stipulated, not specifications of that apparatus. This deterministic leakage test is separate from noise variance, which needs the actual measurement covariance.^[ref] Backgrounds outside the assumed family also need separate treatment.