A Sensor Fusion Scheme Integrating Fiber-Optic Geophone and DAS

In this article, we propose and demonstrate a sensor fusion technology that combines Distributed Acoustic Sensing (DAS) with Fiber-Optic Geophones (FOGs) to enhance both the DAS response and vector detection performance. By analyzing fiber winding losses and the dynamic range limitations of DAS demodulation, we designed and fabricated a 40-mm-diameter FOG to improve DAS sensitivity and enable vector detection. Experimental results show that the FOG achieves a sensitivity of 681.5 rad/g at 23 Hz, significantly outperforming the sensitivity of conventional fiber cables used in DAS. The sensor fusion system is capable of simultaneously detecting phase responses throughout the cable, including transmission fibers and FOGs. This demonstrates the potential of the sensor fusion system to provide comprehensive seismic data with enhanced sensitivity and multidirectional vector probing. Additionally, the transmission fiber, positioned in front of the detector array or between multistage detectors, can enable the FOG array with high detection density.