From 344a36c568c7fdd22d256dd57afa38ccd5701019 Mon Sep 17 00:00:00 2001 From: Frank Dellaert Date: Sat, 8 Jun 2024 16:11:07 -0700 Subject: [PATCH] Added clarification --- gtsam/navigation/AHRSFactor.cpp | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/gtsam/navigation/AHRSFactor.cpp b/gtsam/navigation/AHRSFactor.cpp index 39969a8f3..14548eafd 100644 --- a/gtsam/navigation/AHRSFactor.cpp +++ b/gtsam/navigation/AHRSFactor.cpp @@ -54,8 +54,10 @@ void PreintegratedAhrsMeasurements::integrateMeasurement( PreintegratedRotation::integrateMeasurement(measuredOmega, biasHat_, deltaT, &D_incrR_integratedOmega, &Fr); - // first order uncertainty propagation - // the deltaT allows to pass from continuous time noise to discrete time noise + // First order uncertainty propagation + // The deltaT allows to pass from continuous time noise to discrete time + // noise. Comparing with the IMUFactor.cpp implementation, the latter is an + // approximation for C * (wCov / dt) * C.transpose(), with C \approx I * dt. preintMeasCov_ = Fr * preintMeasCov_ * Fr.transpose() + p().gyroscopeCovariance * deltaT; }