  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.
