Development of a High-Gain Rotational-Motion Seismograph

本研究项目的目的是研制一种用于测量地震波旋转运动的新型光纤陀螺。便携式的灵敏度目标值小于10；-9 rad/秒，长周期类型的灵敏度目标值小于10；-1 rad/秒。便携式频率范围为0.02-50赫兹，长周期频率范围为0.01赫兹-1赫兹。光纤陀螺具有以下优点。通过增大光纤环的尺寸很容易提高灵敏度，而且它没有产生内部噪声的运动元件。由于这些优点，我们选择光纤技术作为旋转运动地震仪的基础技术。我们用三个高增益光纤陀螺研制成功了三轴旋转地震仪，其内部噪声降到了5×10~(-9)rad/s。为了确认新的高增益旋转地震仪的性能，我们使用另一种基于不同技术的旋转传感器进行了并行操作。我们使用的是EENTEC公司生产的R1型旋转传感器。R-1是采用最先进的电化学技术的传感器系列之一，在1赫兹时分辨率为5 x 10；-7 rad/s。总之，我们已经成功地研制出了能够记录局部小震的新型高增益旋转地震仪。

The aim of this research program is to develop a new fiber optic gyro for measuring rotational motion of seismic waves. The target value of sensitivity is less than 10^<-9> rad/sec for portable type and 10^<-1> rad/sec for long-period type. The frequency ranges are 0.02 Hz - 50 Hz for portable type and 0.01 HZ - 1 Hz for long-period type. Fiber optic gyro has the following advantages. It is easy to increase sensitivity by enlarging the size of the fiber coil, and it has no moving elements which make internal noise. Because of these advantages, we select a fiber optic technology as a basic technology of the rotational-motion seismograph. We have succeeded in developing a triaxial rotational seismograph using three high-gain fiber optic gyros whose internal noise is reduced down to 5 x 10^<-9> rad/sec. To confirm the performance of the new high-gain rotational seismograph, we perform a parallel operation using another rotational sensor based on a different technology. We used a rotational sensor model R1 produced by EENTEC.The R-1 is in a line of sensors using state-of-the-art electro chemical technology, and the resolution is 5 x 10^<-7> rad/sec at 1 Hz. Anyway, we have succeeded in developing the new high-gain rotational seismograph which can record local small earthquakes.