Cascade Filter for Precise Gravimeter Signal Processing

In order to suppress serious background noise and get high precise gravity information from the measurement signal of the precise gravimeter, based on the morphological filter and the improved adaptive Kalman filter, a new cascaded filter method is proposed and applied to filter the gravity signal in real time measurement. In the signal processing procedure, the morphological filter is firstly used to eliminate the heavy pulse noise which sometimes leads to huge deviation error of the system model and depresses the performance of the adaptive Kalman filter. Then, the improved adaptive Kalman filter which uses the gravity anomaly state equation as system equation - is set to estimate the actual gravity signal. Emulations and experiments indicate that either the cascade filter method or the improved adaptive Kalman filter method has the better performance than that of the classical Kalman filter, and the performance of the cascade filter method is the best.