An augmented reality device has a radar system that generates radar maps of locations of real world objects. An inertial measurement unit detects measurement values such as acceleration, gravitational force and inclination ranges. The values from the measurement unit drift over time. The radar maps are processed to determine fingerprints and the fingerprints are combined with the values from the measurement unit to store a pose estimate. Pose estimates at different times are compared to determine drift of the measurement unit. A measurement unit filter is adjusted to correct for the drift.