By using zero shill rectifying, digital filter and cutting, the precision and depth of transient Rayleigh wave exploration can be considerably improved.

Application of Multiscale Estimation to ZUPT for Terrestrial Navigation Vehicle;

The accumulated error of SINS can be fixed by the Zero Velocity Update (ZUPT) technology effectively without any auxiliary system.

A zero-calibration for piezoelectric velocity gyro was proposed,in which digital filter was applied to tracking and picking up the gyro zero position,and an effective threshold was set according to the missile s working environment on helicopter to ensure the reliability of zero-position being picked up.