Demonstration of static atomic gravimetry using Kalman filter

TL;DR

This paper introduces a Kalman filter-based approach to improve static atomic gravimetry by reducing white Gaussian noise, achieving higher sensitivity and precision in gravity measurements over extended periods.

Contribution

The work applies a Kalman filter to static atomic gravimetry, effectively reducing measurement noise and surpassing the quantum projection noise limit at certain timescales.

Findings

Sensitivity of 0.6 nm/s^2/√s achieved

Measurement noise below quantum projection limit at ~30 s

Precision of 1.7 nm/s^2 at single sample time

Abstract

The measurement precision of the static atomic gravimetry is limited by white Gaussian noise in short term, which costs previous works an inevitable integration to reach the precision demanded. Here, we propose a statistical model based on the quantum projection noise and apply the Kalman filter to the waveform estimation in static atomic gravimetry. With the white Gaussian noise significantly removed by the the Kalman-filter formalism, the measurement noise of the gravimetry is reshaped in short term and shows $\tau^{1/2}$ feature that corresponds to random walk. During 200 hours of static measurement of gravity, the atomic gravimeter using Kalman filter demonstrates a sensitivity as good as 0.6 $\rm{nm/s^2}/\sqrt{\rm{s}}$, and highlights a precision of 1.7 $\rm{nm/s^2}$ at the measuring time of a single sample. The measurement noise achieved is also lower than the quantum projection limit below $\sim$ 30 s.