Lattice digital filtering techniques have developed rapidly during the past ten years. The achievement are of interest in the earthquake wave date processing field. In this paper, we report the results of three lattice filtering applications on the strong-motion data and observation. The first is an application to estimating the frequency-wavenumber spectrum. An all-zero complex lattice filter is applied to the strong-motion array data. The next is a model of equivalent observation systems which has two seismometers installed both on the free ground and at the bottom of borehole. An all-pole lattice filter is applied to such abservation system for the modeling of earthquaker response of multi-layer system for SH waves The last is implementation of digital integrator with lattice structure. We show velocity seismograms obtained at the depth of 500m by using such digital integrator.
