Local Level Lab

Airborne measurements. Open methods.

Native factorization to qualify

The component implementation lll.ilvis0_shared_reference_terms defines the shared vectors, conservative radii, source/expansion binding and mandatory 27-plus-6 column interface. Its local tests cover nonzero rotation/lever centers, actual nonzero levers, product identities and inconsistent bindings. It does not yet supply a factored native remainder.

Preserve initial velocity algebraically

Let v = v_initial + delta_v. In the midpoint update, with skew argument a and B = (I+[a]x)^-1, compute the velocity increment as

increment = -2 B (a x v) + B rhs.

Accumulate delta_v directly and reconstruct the complete velocity from the initial bound plus that increment. The estimate used for the native midpoint must remain the same estimate as in the original solver; changing it to an average based on the final corrected velocity would change the numerical model.

For each coordinate let m_initial be a fixed initial metric coefficient and m(position) the bounded current coefficient. Split rates exactly:

rate = m_initial*v_initial + m(position)*delta_v + (m(position)-m_initial)*v_initial.

The residual integral contains only the last two terms. The reference product uses the correlated clock, rather than separately multiplying the uncertain initial velocity by every uncertain packet cutoff.

Write the clock as S = S_center + slope*delta_tau + e_clock. The initial velocity is linear in its three calibration coordinates. Its product has a shared term slope*m_initial*gamma_v; after separating it, a conservative remaining product allowance is

(|reference_rate_center| + reference_rate_change) * clock_remainder.

Any nonzero reference-rate remainder also needs its complete product terms; the shortcut above assumes the declared reference rate is linear. Intermediate body/geographic states must retain the full reference-product bound. Only the final observation may factor out the common term. This preserves its indirect effects on metric, field and transport calculations.

Preserve the initial lever remainder algebraically

Let initial_action = R0 L. Its full change bound remains available, but its Taylor remainder is the shared vector gamma_L. Map a value with the same center/change and zero unshared remainder through the final metric. The metric-times-action cross term must still use the full action change, including the shared uncertainty. The removed term is metric_center * gamma_L.

The remaining action is (Rt-R0)L. An operator-norm bound for Rt-R0 follows from telescoping the left navigation and right body rotation products:

B_rotation = min(2, sum(body_angle_bounds) + navigation_rate_bound*T).

A conservative speed bound is the initial speed bound plus all corrected delta-V norm bounds and gravity_max*T, because the Cayley factor is a rotation and its inverse-skew factor is a contraction. It bounds height/latitude variation, positive geographic metric minima and transport rate. Unsupported polar/metric domains must abstain. Restore the actual model/removal background bound; no physical term disappears.

For a general nonzero lever center, the derivative of Rt-R0 applied to the parameter displacement is bounded by the sum of the current/initial attitude change and remainder bounds. Consequently a safe, possibly loose action remainder is

B_rotation*(lever_max + lever_center_norm + lever_change) + derivative_delta_rotation_bound*lever_center_norm.

Its actual center is (Rt_center-R0_center)*L_center, and its full change can be bounded by B_rotation*lever_max + norm(actual_center). Passing those bounds through the geographic metric retains the metric's derivative and cross terms. At a zero lever expansion center this simplifies substantially while still covering every nonzero actual lever in the original region.

Joint output contract

The complete mean and 27 native tangent columns remain those of the original physical predictor. The six added columns multiply normalized bounded shared vectors. Coefficients and all epochs must have the same source/domain/expansion binding. A native consumer cannot use a shortened unshared remainder without the associated columns. Distinct recordings cannot share a block merely because their configuration bytes agree.

Qualification must subtract the actual known-control shared vectors from each native Taylor residual before checking the unshared remainder. Include both signs, nonzero centers, timing endpoints and all candidates/processing cases. Reconcile total centers/Jacobians against the unchanged engine and preserve full inputs, inequalities and certificates. A pass still does not establish whole-program numerical enclosure or observational coverage.

Design and gates · Saved diagnostic evidence · Roadmap.