Land seismic source method and apparatus

Method and apparatus for maximizing seismic shear wave productio

Method and apparatus for seismic exploration using non-linear sw

Method and apparatus for seismic exploration using nonlinear swe

Method for generation of acoustic vibrations and source of acous

Method of seismic exploration using elliptically polarized shear

Multivibrator waveform monitoring system

Multivibrator waveform monitoring system

Oscillating orbital vibrator

Pre-loaded vibrator assembly with mechanical lock

Pressure feedback servovalve for a seismic vibrator

Process and apparatus for analyzing and controlling energy trans

Protective drive-level limiter for an electro-hydraulic vibrator

Reaction mass acceleration feedback device

Seismic source vibrator having improved sweep generator

Seismic source vibrator having self tuning controller

Seismic source/receiver probe for shallow seismic surveying

Seismic vibrator control system

Seismic vibrator hold-down weight monitor/controller

Seismic vibrator source having improved phase detector