Low-Frequency Tilt Seismology with a Precision Ground-Rotation Sensor
نویسندگان
چکیده
We describe measurements of the rotational component of teleseismic surface waves using an inertial high-precision ground-rotation sensor installed at the Laser Interferometer Gravitational-Wave Observatory (LIGO) Hanford Observatory (LHO). The sensor has a noise floor of 0:4 nrad= Hz p at 50 mHz and a translational coupling of less than 1 μrad=m enabling translation-free measurement of small rotations. We present observations of the rotational motion from Rayleigh waves of six teleseismic events from varied locations and with magnitudes ranging fromM 6.7 to 7.9. These events were used to estimate phase dispersion curves that show agreement with a similar analysis done with an array of three STS-2 seismometers also located at LHO.
منابع مشابه
Precision and Reliability Incensement of Inertial Navigation System with Rotation and Redundancy
Precision and reliability are two main performance characteristic in low-cost Inertial Navigation System(INS). Increase of precision in low-cost INS without auxiliary sensors is main challenge. Bias instability leads to position drift error in inertial navigation system. In addition, fault occurrence makes the sensor reliability is decreased. Rotation of Inertial Measurement Unit(RIMU) and use ...
متن کاملA high precision, compact electromechanical ground rotation sensor.
We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor...
متن کاملOn the Use of Mechanical Filters to Attenuate the Transmission of Tilt Motion to Inertial Sensors
Inertial sensors such as seismometers, geophones, and accelerometers cannot distinguish horizontal motion from tilt motion. Rotation measurements can be used to subtract the tilt component from horizontal measurements, but the noise in the tilt sensor is often a limiting factor. No mechanism can change the dual sensitivity of inertial sensors to tilt and translation, but the transmission of gro...
متن کاملPassive, free-space laser gyroscope
Laser gyroscopes making use of the Sagnac effect have been used as highly accurate rotation sensors for many years. First used in aerospace and defense applications, these devices have more recently been used for precision seismology and in other research settings. In particular, mid-sized (∼ 1 m-scale) laser gyros have been under development as tilt sensors to augment the adaptive active seism...
متن کاملModeling and experiment of the suspended seismometer concept for attenuating the contribution of tilt motion in horizontal measurements.
Tilt-horizontal coupling in inertial sensors limits the performance of active isolation systems such as those used in gravitational wave detectors. Inertial rotation sensors can be used to subtract the tilt component from the signal produced by horizontal inertial sensors, but such techniques are often limited by the sensor noise of the tilt measurement. A different approach is to mechanically ...
متن کامل