The objective of this work is to sense seismic particle motion by recovering the Doppler shift of a laser beam that is directed to various ground spots from a remote location. This paper presents results from two field tests using experimental, laser-based, data acquisition systems. In the first test, strong ground-roll vibrations were detected at an 800-m range by reflecting the beam directly from various terrain targets. The weaker, seismic-reflection events were inundated by a noise associated with propagation of the laser beam through the atmosphere. The second test used a novel optical interferometer that cancelled the turbulence noise. A reflector apparatus is needed at the ground target position to cancel the turbulence effects in this system.

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