Geospace Technologies Corporation
A Houston-based maker of rugged sensing gear that listens to the ground, Geospace Technologies builds the geophones, hydrophones, and cable-free seismic nodes used by oil and gas crews to map what lies beneath the Earth's surface. Born in 1980 as OYO Geospace, a subsidiary of Japan's OYO Corporation, it struck out on its own and renamed itself Geospace Technologies in 2012. Beyond oil, its gear now tracks leaky water pipes, guards borders with seismic-acoustic sensors, and even spots intruders by their heartbeat.