Measurements of Four-Component Fiber Strainmeters Orientation Using Seismic Coda Cross Correlation

The orientation of the horizontal components of borehole strainmeters is crucial for many seismic analysis. However, most methods of orientation measurement require vertical component observation. In this study, we try to search best-estimated orientations of a location-known station-pair by minimizing the energy of cross-correlation functions between tangential and radial components of seismic coda data. Finally, we estimated the orientation of two horizontal four-components fiber strainmeters in a 60-m deep borehole in Lu'an, China. The result shows that this method can provide possible orientations without vertical component observation.