不均匀地质条件下地震动目标定位方法

Localization Method of Seismic Target in Anisotropic Ground

针对不均匀地质条件下地震动信号传播速度差异造成定位精度较低的问题,通过将位置域的传播速度转换为时延域的等效传播速度,提出了一种基于时延-等效传播速度检索表的到达时间差(TDOA)目标定位方法.对等腰直角三角形传感器阵列的定位盲区进行了仿真分析,为消除定位盲区,提出了五元十字阵传感器布置方法;进行了场地试验,对运动车辆进行目标定位,对基于时延-等效传播速度检索表的TDOA定位方法与固定传播速度TDOA定位方法的定位结果进行了比较,结果表明,前者的定位效果远优于后者.

In order to solve the problem of low seismic target localization accuracy due to propagation speed variation in anisotropic ground, a novel target localization method was proposed based on the time difference of arrival （TDOA） from the time delay-equivalent propagation speed search table through transforming a position-related propagation speed into a time delay-related equivalent propagation speed. A simulation was carried out to investigate the localization ambiguity area with a fight isosceles triangle sensor array. To eliminate this ambiguity area, a five-sensor cross array was put forward. A field experiment was conducted to locate a moving vehicle. The localization results based on the proposed method and the traditional TDOA based method assuming a constant propagation speed of seismic signal were compared with. The comparison result shows that compared with the traditional TDOA based method, the proposed method is much more efficient.