The low noise performance of Silicon Audio’s optical seismometer surpasses that of MEMS and conventional geophones. With a high clip level, the seismometer’s wide dynamic range matches that of state-of-the-art analog-to-digital converters, enabling system integrators to make full use of the data. In marine seismic environments, the technical attributes of the optical sensor enable capture of both incident gun signals and returning subsurface signals at order of magnitude smaller amplitudes. The ability to capture low-frequency (sub 1Hz) signals with high fidelity translates to an additional decade of low-frequency data for deeper imaging into the seafloor.
Silicon Audio’s rugged 3-axis optical seismometer is designed to withstand the rigors of marine seismic deployment and can be customized to fit within existing acquisition systems.
Silicon Audio’s omni-tilt sensor operates in any orientation, enabling rapid deployment without the hassle and additional operating expense of leveling. This sensor demonstrates a 360-degree tilt tolerance when its response is measured over all possible inclinations using a special rotation table. The chart to the right plots the sensor’s sensitivity to tilt at 20Hz.
Silicon Audio has developed unique facilities specific to testing and qualifying the optical seismometer for marine seismic environments, performing sub 5ng/√Hz noise measurements in a special chamber held to freezing temperatures as experienced on the seafloor. Our ocean bottom simulator includes a custom, large-throw coil driver to simulate transient gunboat waveforms, while time domain data are captured to test signal integrity in response to simulated shots of varying amplitude.
The image below depicts data from one run of the ocean bottom simulation. To prepare the test, a reference sensor is placed in the z direction and a 3-axis seismometer is placed in the cooling chamber at an angle so that all three sensors (x, y, and z) experience equal amplitudes. At lower-drive amplitudes designated by the gunboat’s distance from the zero position, all sensors are active and responsive. The test characterizes sensor clip levels by emulating increasing levels of shock at subsea conditions.