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Sensor Corrections for Multi-Component Monitoring of Seismic Translation and Rotation

Description: 

Seismic sensors are used in a variety of applications, such as monitoring of volcanic activity, structural changes in buildings, seismic velocity changes due to anthropogenic activities or seismic ground motion on land or underwater. All applications depend on the sensors reliably recording the motion above the frequency-dependent noise level of the sensors. However, many of the sensors in use are susceptible to errors that derive from the rotational motion that coexists with the translational motion. For example, inertia motion sensors that rely on translational acceleration observations, such as strong motion or broadband sensors, are affected by rotations through changing attitude of the body to the local frame, leading additionally to gravitational errors and inertial effects such as Coriolis, centrifugal, and Euler forces. GNSS sensors, on the other hand, are affected differently and will show errors due to tilting of the antenna pole or phase wind-up from torsional motion. Without a collocated rotational sensor it is impossible to distinguish, which part of the signal is translation and which is due to rotations. Most of these rotation effects can be corrected with appropriate methods if the local dynamic and static rotations are known. However, to correct for inertial effects, additional information on the distance between the point of rotation and the sensor itself is required. This might not be possible in field observations. Unfortunately, the sensor measuring rotations is also falsified by the dynamic tilt and torsion which misorient the sensor and additionally the false projection of the Earth’s rotation rate.

Here, we show how the observations from the rotational sensor can not only be used to self-correct for misorientation of the body versus the local system, but additionally correct for the error that derives from the earth’s rotation rate being wrongly projected on the channels. The correction scheme will be provided using not only Euler angles but also the more precise quaternion angles. We will present results from the application of different correction schemes on synthetic test scenarios.

Session: Network Seismology: Recent Developments, Challenges and Lessons Learned - IV

Type: Oral

Date: 5/2/2024

Presentation Time: 11:30 AM (local time)

Presenting Author: Yara

Student Presenter: No

Invited Presentation: 

Authors